DC Systems, Energy conversion & Storage
Matchmaking Event
25th April 2018
Efficient Energy Conversion Electromechanics and Electric Mobility
DC Grids and Storage for Smart Cities High Voltage DC Systems
High Voltage DC Diagnostics and Monitoring High Voltage DC Materials and Components
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
HARMONIC MODELLING IN OFFSHORE WIND POWER PLANTS
Type of project: MSc thesis
Scope: Computer modelling of an Offshore Wind Power Plant for harmonic studies
Problem definition:
Due to the increasing penetration of power electronics, harmonic emissions are becoming a prevalent
phenomenon in electric power grids. The increased bandwidth of converters might overlap with these
harmonics, creating unexpected and undesired interactions.
In the case of Large Offshore Wind Power Plants (OWPPs), the concern for power quality is higher due to
several reasons. First, the existence of numerous harmonic sources in these systems. Second, the fact that
offshore wind power plants are typically connected to weak points in the grid, whose sizeable equivalent
impedance might interact with the OWPP. Third, the high capacitance of the long submarine transmission
cables which might create unexpected resonances.
Typically, wind turbines have been modelled as simple harmonic current sources, neglecting possible
interactions in between converters. Even if more complex models have been lately applied, deep knowledge of
what converter parameters (in the control structures and in the physical parameters) are most influential
needs to be developed.
Methodology:
Model a real case study of an Offshore Wind Power Plant
Sensitivity analysis of the parameters of the system
Research Objectives:
Feasibility of the harmonic modelling of a full Offshore Wind Power Plant in Matlab Simulink
Determination of the most influential parameters on harmonic behaviour
Contact details:
PhD student: Lucia Beloqui Larumbe ([email protected])
Supervisor: Dr. Zian Qin ([email protected]),
Prof. Dr. Eng. Pavol Bauer ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
IMPEDANCE-BASED HARMONIC MODELLING FOR OFFSHORE WIND POWER PLANTS
Type of project: MSc thesis
Scope: Computer modelling of a small Offshore Wind Power Plant (OWPP) with a novel method in order to
check its feasibility for harmonic studies in steady state and transient operation
Problem definition:
Due to the increasing penetration of power electronics, harmonic emissions are becoming a prevalent
phenomenon in electric power grids. In the case of OWPPs the concern for power quality is higher due to
several reasons. First, the existence of numerous harmonic sources in these systems. Second, the fact that
offshore wind power plants are typically connected to weak points in the grid, whose sizeable equivalent
impedance might interact with the OWPP. Third, the high capacitance of the long submarine transmission
cables which might create unexpected resonances.
Lately, a new method for the modelling of the wind turbines has appeared: Impedance Based Method (IBM).
The potential of this modelling method is substantial, but before its application it is necessary to determine its
limitations.
Methodology:
Model a small case study of an OWPP in Matlab Simulink with detail (PWM model)
Model the same case study using the Impedance Based Method (IBM)
Comparison in steady state(s)
Further development of the Impedance Based Model into a transient model
Research Objectives:
Detect the limitations of the IBM in steady state
Feasibility of using the IBM, a priori designed for small-signal analysis, for transient analysis
Contact details:
PhD student: Lucia Beloqui Larumbe ([email protected])
Supervisor: Dr. Zian Qin ([email protected]),
Prof. Dr. Eng. Pavol Bauer ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
ANALYSIS AND MITIGATION OF HARMONICS IN OFFSHORE WIND POWER PLANTS
Type of project: Extra Project (15 ECTS)
Scope: Literature review and computer simulations
Problem definition:
Due to the increasing penetration of power electronics, harmonic emissions are becoming a prevalent
phenomenon in electric power grids. The increased bandwidth of converters might overlap with these
harmonics, creating unexpected and undesired interactions.
In the case of Large Offshore Wind Power Plants (OWPPs), the concern for power quality is higher due to
several reasons. First, the existence of numerous harmonic sources in these systems. Second, the fact that
offshore wind power plants are typically connected to weak points in the grid, whose sizeable equivalent
impedance might interact with the OWPP. Third, the high capacitance of the long submarine transmission
cables which might create unexpected resonances.
Lately, considerable changes are occurring in the analysis techniques used in Industry and Academia. In
parallel, several new mitigation techniques, especially through the control of power electronic converters, have
been developed.
Methodology:
Review the analysis techniques used nowadays for harmonic studies in OWPPs
Review the mitigation techniques used nowadays for harmonic emissions and resonances
Small verifications of the concepts through computer simulations in Simulink
Report
Possibility of publishing a conference paper
Contact details:
PhD student: Lucia Beloqui Larumbe ([email protected])
Supervisor: Dr. Zian Qin ([email protected]),
Prof. Dr. Eng. Pavol Bauer ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
OPTIMUM CONCEPT FOR A 1MHZ CONTROLLER AND DRIVER, TO DRIVE THE 1MHZ, 27W,
MOBILE POWER SUPPLY ARCHITECTURE, IN SILICON-ON-INSULATOR PROCESS (SOI)
Type of project: MSc thesis
Scope: Concept for high speed drivers and control in silicon on insulator process
Problem definition:
A 1 MHz, 27W, high power density, flyback power converter will have an active synchronous rectifier at the
secondary side. A correct timing between primary side and secondary side is essential. An active clamp in the
flyback topology will ease this timing requirement. However, it requires a control of an extra floating switch at
the primary side, just like a half-bridge topology. At 1MHz this not straight forward at all. A combination of high
frequency (1MHz .. 2MHz), high voltage (600V) and fast dv/dt, together with our SOI technology, has not been
explored yet.
The challenge for this master thesis is to develop this high side and low side driver structure + related control,
to design it, and to create a test-chip. Finally, this test-chip will be merged into the 27W architecture described
above.
Methodology:
Work out architecture for 1MHz controller concept
Simulation of controller and driver stage
Realize floorplan
Test-chip design
Measurements on test-chip
Research Objectives:
Feasibility of high frequency switching control for AC/DC converter
Explore the boundaries of the used silicon on insulator technology
Contact details:
Company supervisor: Ferdinand Sluijs, [email protected]
Advisor: Arjan van den Berg, [email protected]
University supervisors: Pavol Bauer, [email protected]
Kouchi Zhang, [email protected]
Advisors: Jianning Dong, [email protected]
Zian Qin, [email protected]
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
TEST BENCH AUTOMATION DEVELOPMENT FOR POWER APPLICATIONS
Type of project: MSc internship or thesis
Scope: Automatic characterization of new controller ICs for Smart Power Chargers
Project description:
A complexity of the NXP’s mixed signal controllers requires an extensive testing of their functionality and
performance.
Focus of the project will be on:
1. creating and debugging Matlab scripts for controlling of the external instrumentations such as remotely controlled oscilloscopes and data acquisition units as well as communicating with the device under test using I2C.
2. Creating interface between the existing IC validation test benches and Simulink models. 3. Creating automated reports based on the Excel and Excel VBA.
Requirements:
• Knowledge of the scripting languages preferable Matlab and VBA is required. • Knowledge of Simulink modelling is desired • Some experience in statistics and data processing methods as well as I2C or other interfaces
would be advantageous. • Good report writing ability is required.
Research Objectives:
Automation of characterization of key parameters in power applications, including reporting
Use the results in models for circuit and system simulations
Contact details:
Company supervisor: Ferdinand Sluijs, [email protected]
Advisor: Dimitri Grigoriev, [email protected]
University supervisor: Pavol Bauer, [email protected]
Advisors: Zian Qin, [email protected]
Jianning Dong, [email protected]
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
OPTIMUM CONCEPT FOR A MULTI-OUTPUT, UNIVERSAL MAINS, 1MHZ, 27W, MOBILE
POWER SUPPLY WITH A POWER DENSITY OF >25W/INCH3
Type of project: MSc thesis
Scope: Concept and model of 1MHz adapter in mobile applications with high power density
Problem definition:
Nowadays smart phone chargers become more and more intelligent and powerful. The primary reason is to
reduce charging time. The current sweet spot is 27W charging power. The phone and adapter will “talk” to
each other to select the optimum voltage / current combination. Traditionally a standard flyback topology is
chosen. Together with a secondary side synchronous rectifier and protocol controller an efficient, intelligent
charger can be built. Going to higher switching frequencies will enable us to increase the power density as
(power) components will become smaller. Multiple physical domains are involved:
Electrical domain, especially how to overcome switching losses that will become dominant in 1MHz
applications. The wide input and output voltage range is a challenge. What do new types of switches
like GaN bring?
Thermal domain, the temperature constraints will not change. So how to solve the thermal issues
when we make the charger smaller?
Magnetic domain, how to create the optimum isolated transformer for the 1MHz frequency range.
And that can meet the EMI regulations at the same time.
Methodology:
Simulate and model the targeted adapter
Build the adapter
Measurements and comparison against model
Research Objectives:
Feasibility of a predictive adapter model with wide input and output voltage range
Influence of the parasitic components at high frequency operation
Contact details:
Company supervisor: Ferdinand Sluijs, [email protected]
Advisor: Arjan van den Berg, [email protected]
University supervisor: Pavol Bauer, [email protected]
Advisors: Zian Qin, [email protected]
Jianning Dong, [email protected]
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
RESONANT CONVERTER WITH GAN SWITCHES (100 - 300W)
Type of project: MSc thesis
Feasibility study and demo project for a 100 – 300W mains isolated resonant converter, wherein for size & loss
reduction the traditional Si-MOSFETs are replaced by GaN switches, and a high switching frequency. There is
already a controller for a very high efficient resonant power supply, but further improvement is still highly
wanted.
Scope:
Reduction of size and losses in a power supply saves energy and raw materials. For size reduction a high
switching frequency is a must.
Problem definition:
There is ongoing request for reduction of waste energy and reduction of size of power supplies for various
applications Also from an environmental point of view this is highly preferable. One of the key issues for this is
switching at very high frequency. Present day Si MOSFETs have only limited capabilities to switch at high
frequency. GaN switches promise to overcome this limitations, as they have low on-resistance, low
capacitances, easy drive and fast switching. Before proposing this to the market a feasibility study must be
carried out to verify whether the new switches indeed live up to their promises.
Methodology:
1. study the behaviour of the normal operation of a resonant converter. 2. make a rough model for the losses n the GaN switch to verify optimal frequency setting 3. design a resonant converter for 1 MHz, incl. the mains filter for CM noise 4. build the converter 5. measuring efficiency etc. and verify EMC behaviour
Research Objectives:
study hf switching with GaN in a mains isolated resonant converter (
investigation of influence of parasitics in this type of converters
verify optimal usage of GaN switches
Collaboration with Industry: Yes. The study is preferably done at the NXP premises in Nijmegen, in an expert-
group on world class flyback and especially also world class resonant converters
Contact details:
NXP: Ferdinand Sluijs, ([email protected])
Supervisor at TUDelft: Frans Pansier ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
REPLACEMENT OF OPTOCOUPLER BY RF COMMUNICATION THROUGH TRANSFORMER
Type of project: MSc thesis
In mains isolated converters most often the control information is transferred by means of an optocoupler. Can
this be replaced by a rf signal using the existing transformer?
Scope:
In a mains isolated flyback converter reducing component count and increasing efficiency simultaneously. The
numbers of chargers etc for mobile equipment is huge. Any reduction of power consumption and component
count help reducing pollution, and reduces the consumption of raw materials
Problem definition:
In most isolated converters the control info is transferred from secondary side to primary side using an
optocoupler. This coupler consumes energy, and adds to cost. The questions arises: can the transfer of
information be done with components that needs to be used anyhow, esp. the transformer. A transformer can
be used for transferring power, but also for transferring information. Can this be done with the same
transformer? A potential candidate is to use an rf signal to be coupled to the transformer to do this. The
bandwidth of the communication must be large enough and the communication should be bidirectional,
paving the way for more sophisticated features.
Methodology:
6. study the behaviour of the normal operation of a flyback converter as used for chargers 7. study the possibility of transferring power and hf information using the same transformer, including
constraints on frequency span, sensitivity for noise, etc. 8. proposal for the way the information is transferred by means of a hf signal (e.g.: pulses (with
protocol), fm modulation, etc.) 9. building prototype, and assessing feasibility (efficiency, performance,cost etc.)
Research Objectives:
knowledge on multi-purpose use of transformers for power supplies
knowledge on interaction of hf signals and switched mode power transfer in transformers
optimisation of efficiency and size of power supplies with mains isolation
Collaboration with Industry: Yes. The study is preferably done at the NXP premises in Nijmegen, in an expert-
group on flyback converters
Contact details:
NXP: Ferdinand Sluijs, ([email protected])
Supervisor at TUDelft: Frans Pansier ([email protected])
10
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
OFFSHORE WIND FARM ELECTRICAL OPTIMISATION AND GRID COMPLIANCE
ASSESSMENT
Type of project: MSc thesis
Scope:
Offshore wind farm (OWF) optimisation by analyzing and comparing different options for collector system, system voltage, offshore high voltage station (OHVS) and assessment of grid compliancy. Problem definition:
The cost of energy from offshore wind has fallen by 32% since 2012 and is now below the joint UK government
and industry target of GBP 100 per megawatt hour (MWh) four years ahead of schedule, according to a
report delivered by the Offshore Renewable Energy (ORE) Catapult on behalf of the Offshore Wind Programme
Board (OWPB). "Subsidy-free" offshore wind is getting a lot of attention after contracts in Germany and the
Netherlands were signed without direct government incentives.
Optimisation of the technical aspects is key in achieving OWF cost reduction and this is what this project will
explore, where the main components of an OWF and key technical constraints will be considered as input
parameters.
Methodology:
Model the offshore wind farm and optimise the electrical configuration in MATLAB
Analyze grid compliancy based on one of the ENTSO-E countries codes
Create an integrated fully functional friendly MATLAB with an in-built GUI
Research Objectives:
Optimisation of offshore wind farm electrical system based on CAPEX and OPEX by considering: the number and siting of Offshore High Voltage Stations (OHVS), the layout of both the interarray and the export cables as well as the selection of electrical components in terms of voltage level and capacity.
Case study of optimizing an OWF and checking grid code compliancy. Theory will have to be complemented with simulation studies to give a systems perspective and a better understanding for techniques involved in meeting grid code demands.
Delivery of a MATLAB model with a GUI functionality which can be used for any wind farm to achieve the above mentioned objectives.
Contact details:
Company contact: Maria Kalogera, [email protected]
University supervisor: Prof. Pavol Bauer, [email protected]
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MAXIMISATION OF ENERGY PER AREA AND LOAD FACTOR IN UTILITY SCALE SOLAR PV
Type of project: MSc thesis
Scope:
Utility scale solar farm maximization of power generation per area and load factor by analyzing and comparing different options for mounting systems, ground coverage ratios (GCRs), including tracking systems and east-west mounting systems, module types and DC-AC ratios. Problem definition: The installation of utility scale solar farms is accelerating globally. While the focus so far has been mostly on reducing cost, in the future land area will become a more important constraint. In fact, in some densely populated countries, including the Netherlands, land availability for solar PV is already limited, leading to sharply rising land prices. This induces a pressure to maximise PV installation (and hence energy generation) per unit area. A related pressure is for higher AC load factors, ie maximizing the power generation in the morning and evening hours, as opposed to maximizing the harvesting around noon.
Methodology:
Investigate and compare options for maximizing Energy per Area and AC Load Factor (literature review, expert interviews)
Model different utility scale PV farm designs in the software package PV Syst, for a number of global reference locations
Report optimal PV farm designs given the competing drivers of low cost, high EpA and high AC load factor
Research Objectives:
Present utility scale PV farm designs for maximum Energy per Area and AC load factor, to determine where the practical limits for the parameters are.
Propose an optimal lay-out for a number of locations and circumstances, including the Netherlands and a number of international reference locations
Delivery of a PV Syst models and power generation profiles for these designs and locations.
Contact details:
Company contact: Domnick, Andreas, [email protected]
University supervisor: Prof. Pavol Bauer, [email protected]
Nishant Narayan, [email protected]
Gautham Ram Chandra Mouli, [email protected]
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
IMPROVING CONVERTER RELIABILITY IN ACTIVE SPEED STALLED TIDAL TURBINES
Type of project: Extra Project
Scope: Improving converter reliability is essential to minimizing the cost of energy from tidal turbines. Wide
fluctuations in speed of tidal turbines (<300kW) due to the turbulence in tidal velocities can impose heavy
thermal loading on the power converter. This is especially true for fixed-pitch turbines. The converter loading
has a significant impact on its lifetime, and hence, the maintenance cost of the tidal turbine.
Problem definition: Investigate the influence of the speed fluctuations in a fixed-pitch tidal turbine on the
converter lifetime. Investigate the different solutions (control strategy, converter topology, etc.) for prolonging
the mean time to failure.
Methodology: The converter current is calculated by coupling the turbine mechanical model with
electromechanical models for the generator and the converter. Based on the converter currents, a thermal
model is used to estimate the thermal cycling in a tidal power converter, and mean life to failure is estimated.
Different speed control strategies, converter topologies, etc. can then be compared based on the mean time to
failure.
Research Objectives:
Influence of tidal turbulence on the converter lifetime in a fixed-pitch turbine.
Comparison of different converter topologies based on their lifetime.
Suggesting optimal topology or speed control strategy for maximum lifetime.
Collaboration with Industry: Yes
Contact details:
PhD candidate: Faisal Wani ([email protected])
Supervisor: Dr. Jianning Dong ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
WIND POWER OUTPUT PREDICTION CONSIDERING COMPONENT DEGRADATION
Type of project: MSc Thesis
We are getting old…
Photo courtesy: Tim Strous
Scope: This project aims at wind power output prediction considering degradation of different components in
wind turbine, while concentrating on the electrical generator system.
Problem definition: As the share of wind power grows large, operation and maintenance (O&M) cost reduction
becomes a catching and demanding topic. Power output prediction is an important part to schedule O&M to
reduce cost. The power output depends on many factors. The degradation of different components, e.g.
blades, power electronics and generators leads to efficiency and availability reduction, but has not been well
understood. This project will explore the influence of component degradation on wind turbine availability, so
that the wind power output can be predicted with quantification of uncertainty. Special attention will be paid
on power electronics converters and wind generator.
Methodology: The project includes literature review, modelling and simulation.
Research Objectives:
Overview of the state of art of wind turbine degradation and availability research.
Model the availability of the generator system considering degradation.
Case study of power output prediction of an offshore wind turbine.
Collaboration with Industry: No.
Contact details:
PhD student: Udai Shipurkar ([email protected])
Daily Supervisor: Dr. Jianning Dong ([email protected])
Supervisor: Prof. Pavol Bauer ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
SOLID-STATE HYBRID CIRCUIT BREAKER – TOPOLOGY COMPARISON
Type of project: MSc thesis
Scope: The two main challenges of meshed low voltage DC grids today are the flexible control
of power flow and the short-circuit protection. The conventional approach to deal with both problems is to incorporate galvanically isolated DC-DC converters with integrated short-circuit protection, which are rated for the full power rating of the grid. In this thesis, we develop an approach based on the combination of a converter which has a partial power rating with respect to the grids power rating and a circuit breaker with full rating with respect to the grid.
Problem definition: Power electronic converters have a limited over-current withstand capability. The breakdown voltage of the semiconductor devices cannot be exceeded at any time. Oversizing the converters for higher currents and/or voltages is possible, but expensive. It is more efficient to develop fast and reliable circuit breakers to protect the converters from the short-circuit effects.
Methodology: In the first phase the student will familiarize with the protection practices and the concept of
partially rated converters for power flow control through literature study. The core of the work load is
evaluating different circuit breaker topologies for the power flow control converter.
Research Objectives:
Define a set of appropriate circuit breakers for partially rated power flow control converter
Analyse and compare the circuit breakers using simulation
Laboratory prototype testing with the partner institution (optional)
Collaboration with Industry: It is an option, Fraunhofer-IISB
Contact details:
PhD student: P.Purgat ([email protected])
Supervisor: dr. Zian Qin([email protected])
prof. P. Bauer ([email protected])
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
DESIGN AND OPTIMIZATION OF THE ELECTRICAL SYSTEM FOR AN AIRBORNE WIND
ENERGY WINCH
Type of project: MSc thesis
Scope: Design and optimization of the electrical system for an airborne wind energy winch. The winch should
be optimized for power generation (reel-out), reel in and temporary energy storage.
Problem definition: The system generates electric power by converting the pulling of the kite in to a rotary
motion and driving a generator. The system should also function as a motor to pull back the kite to the start
position, with a fraction of the energy which was generated. In order to ensure a continuous power output also
an energy storage system is installed. The current 100 kW system is a test system. MSc Thesis would consists of
the preliminary design of the commercial system, including configuration (DC, AC), component selection,
optimization and economical aspects.
Methodology: Optimisation and field test of current system, simulation of improved system, economic analysis
Research Objectives:
Investigate limitations current 100 kW system
Requirements commercial system
preliminary design of commercial system
Collaboration with Industry: Yes, Kitepower (spin-off TUDelft)
Contact details:
Daily Supervisor: Jianning Dong, [email protected]
Supervisor: Joep Breuer, Technical Manager, Kitepower, [email protected]
16
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
LEARNING WITH THE LAB-SCALE MODULAR MULTILEVEL CONVERTER
Type of project: Extra Project (15 ECTS)
Scope: The available lab scaled modular multilevel converter (MMC) can be used to gain knowledge on real
time digital simulator (OPAL-RT) and other hardware operation.
Problem definition: Experiment with the available lab-scaled MMC to understand the operation principles. Its
operation will then be tested by applying different control strategies.
Methodology: Laboratory work is expected.
Research Objectives:
Learn and test different PWM techniques and generate the required carrier wave to switch the
submodules. .
Apply simple control schemes, for instance capacitor balancing to test the proper operation of the
available lab-scale MMC.
Collaboration with Industry: <No>
Contact details:
PhD student: <A. Shekhar, [email protected]>
Supervisor: <Zian Qin; Pavol Bauer>
1.
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D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MODULAR MULTILEVEL CONVERTER AS STATCOM
Type of project: MSc thesis
Scope: This project explores the use of modular multilevel converter (MMC) for harmonic elimination1. The
concept is to be applied to mitigate the power quality issues and highlight the trade-offs and challenges
therein.
Problem definition: Develop schemes to detect and mitigate medium voltage grid current and voltage
harmonics by operating a MMC as STATCOM. Different harmonic detection and current injection strategies
need to be implemented and compared in terms of power quality conditioning.
Methodology: Simulations as well as experimental work is desired. The student is expected to learn about the
operation of the MMC and develop control techniques to comply with different grid requirements at medium
voltage level.
Research Objectives:
Identifying the methodology to detect harmonics at the point of common coupling (PCC).
Determining how fast the convertor needs to react while keeping its internal balancing.
Showing the operation of MMC as STATCOM for harmonic elimination experimentally.
Compare different methods of achieving harmonic elimination using MMC and 2 level VSC.
Collaboration with Industry: <No>
C ontact details:
PhD student: <A. Shekhar, [email protected] >
Supervisors: <L. M. Ramírez-Elizondo; Zian Qin; Pavol Bauer>
1 E. Kontos, G. Tsolaridis, R. Teodorescu and P. Bauer, "High Order Voltage and Current Harmonic Mitigation Using
the Modular Multilevel Converter STATCOM," in IEEE ACCESS, vol. 5, pp. 16684-16692, 2017.
2.
18
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MODULAR MULTILEVEL CONVERTER (MMC) WITH DYNAMIC DC LINK VOLTAGE
Type of project: MSc thesis
Scope: It is possible to increase the dc link voltage without increasing the voltage ‘seen’ by the converter
switches in a MMC. This improves the efficiency of the system without investing in higher rated components.
Problem definition: Develop a control strategy for operating the dc link with dynamic voltage while keeping the
MMC energy within the rated limits to obtain efficiency and capacity improvement.
Methodology: The student is expected to prove this idea through simulations and implement it experimentally
in the available lab scale converter. The fundamental equations will be given to the student for the
implementation of this concept, for which familiarity with MATLAB is important.
Research Objectives:
Show through simulations that the energy in the MMC can be controlled such that the dc link voltage
can be dynamically raised without increasing the voltage seen by the submodule capacitors and
switches.
Define boundaries within which this concept can be applied.
Determine the achievable efficiency/capacity gains of operating the MMC with dynamic dc link
voltage.
Implement the concept in the available lab-scale MMC prototype to justify the claimed gains.
Collaboration with Industry: <No>
C ontact details:
PhD student: <A. Shekhar, [email protected] >
Supervisors: <L. M. Ramírez-Elizondo; Zian Qin; Pavol Bauer>
19
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MODELLING AND GATE DRIVER DESIGN OF SILICON CARBIDE (SIC) DEVICES
Type of project: MSc thesis
Scope: modelling of Silicon Carbide (SiC) power switches
Problem definition:
SiC has wider bandgap compared with Silicon (Si), which brings SiC devices advantages like higher blocking
voltage, non-reverse recovery, faster switching speed, etc. Because of these advantages, it is promising to use
SiC power devices instead of Si based ones for better performance. But due to the different characteristics
between the two devices, one cannot expect much improvement of the performance by simply replacing the
latter with the former ones in circuit. Therefore, in order to use the SiC device in a proper way and push its
performance to the limit, a better understanding of its characteristics is needed before a SiC device dedicated
gate driver can be designed.
Methodology:
Build a double-pulse testing platform
Study the switching behaviour
Extract the values of the parasitics
Study the impact of the environment, e. g. voltage and temperature, on the parasitics
Research Objectives:
Modelling of the SiC devices
Propose gate driver design and application criteria for the SiC devices
Contact details:
Supervisor: Dr. Zian Qin ([email protected])
Prof. Dr. Eng. Pavol Bauer ([email protected])
20
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
BATTERY EMULATOR FOR TESTING PE INTERFACE MODULES
Type of project: MSc thesis
Scope: Design a laboratory setup that can replicate the behaviour of an electrical battery storage unit.
Assemble, program and test the emulator under power electronic (PE) interface conditions.
Problem definition: With the growing interest in nano-grids and a wider utilisation of energy storage units, the
accompanying PE converters that are required to interface and control the power flow need a platform on
which they can be tested. Actual high-power batteries are hazardous to experiments with, while off-the-shelf
emulators are costly and can function in a limited range. The solution therefore is to custom design converters
that can be programed to behave as a battery under both charging and discharging conditions. By
implementing a topology similar to the one in the figure, a wide range of conditions can be achieved by
combining various switches, resistors and quantity of commercially available safer-batteries or power sources.
The task is therefore to design, assemble and program such a setup for laboratory implementation.
Methodology: Assemble a converter based on the layout given in the figure. Choose the appropriate
components and design its PCB board. Program the available controllers to operate the switches in the device.
Test the battery emulator via simulations on a system model and finally laboratory experimentation on the
setup.
Research Objectives:
Identify the key features of a battery emulators.
Design and assemble the emulator based on these features.
Test the operations of this converter via simulation and experimentation.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
21
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
DUAL ACTIVE BRIDGE MODULE FOR MULTILEVEL APPLICATIONS
Type of project: MSc thesis
Scope: Modify a DAB converter to operate as a module in a Multilevel system. By reconfiguring certain
elements on an existing prototype, the module should be able to communicate with other modules while
interfacing certain loads/sources.
Problem definition: Conventional MMC and other Multilevel systems usually implement modules that do not
provide galvanic isolations between their input and out. By modifying existing DAB converters we can
reconfigure them to operate as modules as part of a broader system. The inclusion of certain sensors and
communication ports may also be necessary to achieve access to control parameters and compatibility with
other modules. Reprogramming the DAB converter to function as a module will also be required. Simulation on
a system model and finally experimentation on a laboratory setup will serve as a testing platform and
validation of the expected converter performance.
Methodology: The methodology for this thesis will include getting familiar with the layout and design of the
existing DAB converters. Afterward a reconfiguration process by adding or removing certain elements will be
required. Adjusting the controls for multilevel operations and testing them via simulations should precede the
final experimental verification of the module.
Research Objectives:
Analyse the design and operational principle of DAB converters.
Reconfigure existing DAB converter to operate as an isolated module in a Multilevel system.
Test and analyse the performance of this module via simulation and experimentation on a laboratory
setup.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
22
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
HIGHER RATED PV EMULATOR
Type of project: Extra Project
Scope: Based on the available converters that replicate the power curves of PV cells, the goal is to redesign
them in order to achieve a higher power rating and possibly a more accurate performance.
Problem definition: There are various methods of extracting data from systems that incorporate PV sources.
However, in laboratory environments, where available space is usually limited, any setup needs to be compact
and highly robust. Therefore, by implementing the tools and equipment that are at hand, the task will be to
modify an existing PV emulator for the purpose of testing other converters intended to interface a PV sources.
These emulators function by operating the switch in the linear (active) region while being supplied by a
conventional DC power source. In order to scale up the power rating of the emulator, the student should
reconfigure and possibly reprogram the converter by choosing the proper components and adjusting the
controls to suit their switching needs. Simulations and experimentations should be carried out during the
design process.
Methodology: After getting familiar with the basic design and operating principle of the existing emulator, a
process of redesign should follow. This process includes choosing which elements to preplace and adjusting the
controller to suit them. Assembly, simulation and experimental testing can than take place.
Research Objectives:
Identify key feature of the PV emulator.
Reconfigure the emulator and modify the controls to suit a high power rating.
Test the operations of the converter.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
23
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MULTI-FREQUENCY ACTIVE FILTERING
Type of project: MSc thesis
Scope: Design, build and test a modular series and/or parallel active filter for operation in multi-frequency
micro-grids. This converter will be assembled with pre-existing component submodules equipped with
sufficient sensors and control capabilities. The appropriate control strategy needs to be chosen and then tested
under various conditions.
Problem definition: As part of a novel Multi-frequency micro-grid, the inclusion of a certain components that
provide an enhanced power quality is an important feature. Active filters are common-place in various AC and
DC systems and applications. However, the presence of additional (superposed ) frequencies provides a new
layer of control that needs to be addressed. The physical filtering module (composed from pre-existing
submodules )may require only certain modifications. The main goal is to put forward and test a control strategy
that can actively track and mitigate various harmonics present in the system via the available sensors and
control devices.
Methodology: In order to achieve active filtering under these conditions, certain steps should be followed. This
includes proposing a control strategy based on the available voltage and current measurements. Afterwards,
the control strategy should be tested via a simulations on a Matlab model of the system. Finally, the active
filter should be assembled, tested and evaluated on a laboratory setup.
Research Objectives:
Identify the requirements of MF active filtering.
Propose a control strategy for the MF Active Filter.
Test and evaluate the MF Active Filter via simulation and laboratory experimentation.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
24
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
MULTI-FREQUENCY POWER MEASUREMENT BOARD
Type of project: MSc thesis
Scope: Design, assemble and test a PCB board capable of high-precision measurements of electrical power flow
on various frequencies (including DC) in a MF micro-grid. By incorporating various sensors and available
controllers, a multi-port device should be assembled and programed to track the power flow on individual
frequencies going through it.
Problem definition: In a novel Multilevel, Multi-frequency power systems that is currently being designed,
measurement of power flow is more challenging. This is due to the presence of at least one or more AC
frequencies that are superposed on a DC offset. Power tracking of multiple frequencies can be achieved by a
measurement board containing the proper voltage/current sensors, conditioning circuits and available
controllers. Along with the necessary choice of hardware, the proper algorithms need to be incorporated
within the controller.
Methodology: Firstly a method of isolating and calculating the relevant parameters within the limits of the
available controllers needs to be suggested. This method should then be tested and verified via simulations on
a model MF system. Afterwards, the process of designing the actual prototype board can begin along with the
programing of the controller. Finally, the Measurement Board should be tested on a laboratory setup of the
system.
Research Objectives:
Propose a MF power measuring method.
Design a device to accommodate the required components.
Test the measuring accuracy of the program via simulation and experimentation.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
25
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
POWER ELECTRONIC BUILDING BLOCKS FOR VARIOUS CONVERTER TOPOLOGIES
Type of project: Extra Project
Scope: Implementing existing power electronics submodules to design, assemble and test various common
converter topologies. These include conventional isolated and non-isolated DC/DC and DC/AC converters.
Problem definition: An ideal opportunity for any student that wishes to get hand-on experience with operating
various topologies of widely implemented PE converters. With existing PE “building blocks” ( sub-modules) with
pre-installed switches, sensors and control components a wide assortment of converters can be assembled.
Using standard testing practises, these converters need to be tested under various loads and/or source
conditions. A performance analysis should be presented as part of the final report.
Methodology: Firstly, the student needs to get acquainted with the operating principles of the individual
submodules. After this, a number of possible converter topologies should be suggested along with their control
principle. Finally, adjusting the controller, followed by various experiments under certain conditions will be
carried out in order to demonstrate the PE Building Blocks performance.
Research Objectives:
Identify possible converter topologies.
Experiment with different combinations of PE building blocks.
Test and analyse the performance of the submodules for different topologies.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
26
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
Efficient Energy Conversion DC systems, Energy conversion & Storage
DESIGN AND EVALUATION OF SIC SWITCHING SUBMODULE
Type of project: MSc thesis
Scope: Using available SiC MOSFET switches and high-frequency drivers, the goals is to design a high-
performance half-bridge submodule (SM) for use in “building block” design application. This SM should also
include various sensors, snubbers and communication ports in order to properly function as part of a broader
system.
Problem definition: SiC and other wide band-gap devices are still relatively novel in terms of applications. Due
to their high performance potential, SiC switches could be pushed to high-frequency operation. This is ideal in
some aspects but creates problem in various other domains such as EMI and stress on other components of the
converter. Therefore a proper design is required for modules implementing SiC MOSFETS. This needs to take
into account both the layout and choice of adjacent components. Final incorporation, testing and evaluation of
the SiC switching SM in actual converter topologies (DC/DC, DC/AC) will be carried out.
Methodology: The utilisation of SiC MOSFET switches on a submodule level requires experimentation with
different layouts and design approaches in order to achieve an optimal solution. Several iterations may be
necessary before an acceptable result can be achieve. Simulations and experiments in laboratory setups will be
used in the design phase and final evaluation.
Research Objectives:
Identify the potential benefits and challenges of implementing SiC MOSFET switches.
Design a half-bridge SM that mitigates most of the challenges.
Analyse and evaluate the performance of these submodules.
Collaboration with Industry: No
Contact details:
PhD student: Mladen Gagic, [email protected]
Supervisor: Prof. dr. J.A. Ferreira, [email protected]
27
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
BATTERY SIZING OF EVS FOR ON-ROAD DYNAMIC CHARGING (WIRELESS)
Type of project: MSc thesis
Figure[1]: Dynamic wireless EV charging and dynamic SOC profile
Scope: Dynamic charging of EVs with inductive coupling based wireless power transfer is an attractive research
area. It allows smaller and lighter batteries to be used, due to frequent charging using the charging
infrastructure embedded under roads.
Problem definition: The research challenge in this field is to optimally design a dynamic EV charging system
considering a stochastic driving cycle along an intercity highway. The trade-off between investment cost of a
dynamic IPT system and the reduction of the battery size and extension of the battery life needs to be
investigated.
Methodology: The methodology to arrive at a good design are the following:
Literature review of battery lifetime models and dynamic EV charging system layout
Problem Formulation of a multi-objective techno-economic framework
Sensitivity analysis of stochasticity of driving cycles on battery sizing and lifetime
Research Objectives: The pertinent research objectives are highlighted below:
Quantification of battery size reduction by dynamic charging
Quantification of battery lifetime extension
Multi-objective optimization of techno-economic model
Collaboration with Industry: No
Contact details:
PhD student: S. Bandyopadhyay [email protected], LB 03.640,
Supervisor: Dr. Jianning Dong [email protected], LB 03.630, Prof. Pavol Bauer
[email protected] , LB 03.600
28
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
OPTIMAL COIL TOPOLOGY FOR DYNAMIC WIRELESS CHARGING OF EVS
Type of project: MSc thesis
Figure[1]: Dynamic wireless EV charging and possible coil topologies
Scope: Dynamic charging of EVs with inductive coupling based wireless power transfer is an attractive research
area. The main design challenge of this field is to provide a constant power profile to an in-motion EV.
Therefore, it is necessary to research different coil topologies to select the optimal topology for this
application.
Problem definition: Dynamic IPT systems need to provide a constant power profile for moving EVs. The EV
battery health will deteriorate if pulsed power is used. This design specification needs innovative solutions like
power buffering and misalignment tolerant coil topologies. This research is focused on optimal coil topology
which will ensure low power pulsations.
Methodology: The methodology to arrive at a good design are the following:
Literature review of coil types used in dynamic IPT systems
Electromagnetic model of a lumped multi-coil dynamic IPT system
Optimization and comparison of different coil shapes
Research Objectives: The pertinent research objectives are highlighted below:
Optimal coil topology for dynamic IPT systems
Coil layout and internal spacing guidelines
Multi-objective optimization for efficiency maximization and cost minimization
Collaboration with Industry: No
Contact details:
PhD student: S. Bandyopadhyay [email protected], LB 03.640,
Supervisor: Dr. Jianning Dong [email protected], LB 03.630, Prof. Pavol Bauer
[email protected] , LB 03.600
29
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
THERMAL MODEL OF WIRELESS INDUCTIVE COUPLERS FOR EV CHARGING
Type of project: Extra Project (15 ECTS)
Figure[1]: Wireless inductive coupler arrangement and thermal model
Scope: The possible flexibilities and potential of wireless charging makes it a prime candidate of replacing
conventional wired charging of EVs. However, as the power increases the loss density and thermal behaviour
become the limiting factor. That’s why quantifying the power density limits of the inductive couplers is very
important for designers.
Problem definition: Wireless inductive power charge-pads use materials like litz wire, ferrites and aluminium
which are relatively more expensive than normal copper wires and insulations needed for wired charging.
Charge-pads are of different shapes like DD coils, circular coils , rectangular coils and their loss distribution can
be different depending on core layouts. The goal of this thesis will be to find the thermal weak-links and thus
the power density limits of the charge-pads with or without cooling.
Methodology: The methodology to arrive at a good design are the following:
Thermal modeling using finite element analysis and as well as lumped parameter modeling
Optimization of coil shapes and experimental validation of models
Research Objectives: The pertinent research objectives are highlighted below:
Coil sizing guidelines based on power transfer and airgap specifications
Design trade-offs w.r.t power density and thermal considerations
Comparison of coil shapes based on thermal limits
Collaboration with Industry: No
Contact details:
PhD student: S. Bandyopadhyay [email protected], LB 03.640,
Supervisor: Dr. Jianning Dong [email protected], LB 03.630, Prof. Pavol Bauer
[email protected] , LB 03.600
30
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
DESIGN A CONVERTER FOR EV CHARGING SYSTEMS
Type of project: MSc thesis
Scope:
This MSc assignment entails the design of a PFC converter for electric vehicle charging applications (marked in
red). This part of the power module can be matched to the isolated DC/DC converter that has been developed
in a previous Msc. Assignment (marked in green).
Problem definition: Long term GaN is needed to stay competitive. The prices of the devices are expected to be
on par with current conventional technologies while SiC will always be a bit more expensive. The emphasis is
on technology prototype development I.E. hardware, understanding the week points of the technology. The
sooner we can take new technologies for a spin “outside of the lab”, the better. The prototype will not
immediately be ready for large scale production.
Methodology:
Set general requirements (input voltage: 200V-15% - 240V+10%, 420Vout +/- 20Vripple due to PFC, EMC, power factor, THD, etc.)
2 months literature study -> 1 chapter
2 months simulating 3-5 topologies -> 1 chapter
Refine requirements
Select 1-2 topologies for possible implementation
2 months detailed design of these 1-2 topologies -> 1 chapter
2 months implement, test and benchmark-> 1 chapter
1 month write report
Research Objectives:
Compare different topologies and implement a technology prototype, utilizing GaN (and SiC diodes)
This prototype will possibly be benchmarked against other implementations
This new design should give a benefit for: 1 cost (eventually), 2 efficiency, 3 power density
Contact details:
Company contact: [email protected]
University supervisor: Gautham Ram Chandra Mouli,
([email protected]); Zian Qin ([email protected])
31
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
DESIGN AND MODELLING OF ELECTRIC MACHINE FOR ELECTRICALLY ASSISTED SHORT –
RANGE CIVIL AIRCRAFT
Type of project: MSc Thesis
Scope: Facing the environmental pressure, the aviation industry has to come up with innovative technologies
to reduce its environmental footprint. An electrically assisted propulsion system (EAPS) which embeds an
electrical machine in a conventional turbofan engine can reduce the size and emission of the engine, and
increase the overall efficiency.
Problem definition: The thesis project aims to design a high power density electrical machine which can
operate in parallel with the turbofan engine for short-range mission. Requirements of electrical machines will
be investigated from mission profile, in cooperation with aerospace engineering faculty. Tradeoff between
reliability, efficiency and power density should be made with a preliminary design tool set. Physics based model
should be built for detailed design and analysis of the electrical machine.
Methodology: The project includes electrical machine modelling and simulation based on FEA, circuit and
analytical calculation.
Research Objectives:
Integrative design of electrical machine based on mission profile.
Development of preliminary design tool set for electrical machines in EAPS.
Physics based modelling of PM machine for EAPS.
Collaboration with Industry: No.
Contact details:
Daily Supervisor: Dr. Jianning Dong ([email protected])
Supervisor: Prof. Pavol Bauer ([email protected])
Dr. Arvind Gangoli Rao ([email protected])
32
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
DYNAMIC MODELLING OF A CANNED PERMANENT MAGNET MACHINE
Type of project: MSc thesis
Stator can
Rotor can
Sea water
Scope: Canned permanent magnet machines can be used as motors in marine propellers and as generators in
tidal or wave energy turbines. The canned stator and the rotor structure of these PM machines may not only
cause additional eddy current losses but also influence the dynamic characteristics of the canned PM machine.
Problem definition: The main goal of this thesis is to characterize the impact of the additional inductive effects
of the conductive canned structure on the steady-state and the dynamic characteristics of the PM machine.
Comparisons must be made with the dynamic characteristics of the PM machine with non-conductive glass
fibre cans.
Methodology: The candidate needs to understand the steady-state and dynamic performance of the canned
PM machine, and identify main differences compared to the conventional PM machines. The differences in
operational characteristics can be reflected in terms of the additional differential equations in the circuit model
of the canned PM machine. The developed model needs to be verified against the finite element simulations.
Research Objectives:
Develop a mathematical model for a canned PM machine for steady state and dynamic analysis.
Verification of the equivalent circuit model against finite element simulations.
Influence of can parameters on the performance of the canned PM machine.
Collaboration with Industry: Yes
Contact details:
PhD candidate: Faisal Wani, [email protected]
Supervisor: Dr. Jianning Dong, [email protected]
33
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
FOREIGN OBJECT MODELLING AND DETECTION IN DYNAMIC INDUCTIVE CHARGING OF
ELECTRIC VEHICLE
Type of project: MSc Thesis
Scope: The goal of the project is to analyse and assess the effect of conductive or magneto-conductive objects
placed near the dynamic charging system and seek ways to detect them.
Problem definition: Dynamic inductive charging of electric vehicles means the electric vehicle (EV) is charged
through contactless inductive power transfer while driving. The performance of inductive power transfer (IPT)
system might be affected by conductive or magneto-conductive foreign objects having a limited size (typically
road side refuse, e.g. aluminium cans). The project will evaluate the effects of foreign objects on electrical
waveforms and efficiency of the dynamic IPT system. Method to detect the foreign objects from electrical
quantities will be investigated and implemented.
Methodology: Finite element method and circuit analysis will be used to study the effects of foreign objects.
Analog or digital circuits will be designed and implemented to detect the foreign objects.
Research Objectives:
Modelling the foreign objects in DIPT system
Evaluation of foreign objects on DIPT performance
Methodology to detect the foreign objects
Collaboration with Industry: No.
Contact details:
Daily Supervisor: Dr. Jianning Dong ([email protected])
Soumya Bandyopadhyay ([email protected])
Supervisor: Prof. Pavol Bauer ([email protected])
34
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
HARDWARE-IN-LOOP SIMULATION OF ELECTRIC VEHICLE POWERTRAIN
Type of project: MSc Thesis
Flux Density (T)
Scope: This project aims at development of a hardware-in-loop simulation system of electric powertrain of
electric vehicles.
Problem definition: Hardware-in-loop (HIL) or power-HIL simulations are essential for cost-effect and time-
effective developments of modern powertrains in electric vehicles and electric aircrafts. Control algorithms can
be tested through mathematical dynamic models of electrical machines and power electronics without building
real prototypes. The models of power electronics converters can be replaced with real converters to be tested
if power-HIL is involved. To fully represent the dynamic performance of the powertrain, magnetic saturation,
losses and temperature rise of motors, dynamics of the transmission system, battery and vehicle aerodynamics
should be considered. Comprehensive models should be built and integrated in the real time simulation
platform. Various driving profiles and control algorithms will investigated to validate the effectiveness of the
developed models.
Methodology: Finite element method will be used to generate the dynamic models of electrical machines.
MATLAB/Simulink and OPAL-RT will be used to implement the real-time simulation.
Research Objectives:
Dynamic modelling of different components in EV powertrain
Real time simulation platform of EV powertrain
Comparison of control algorithms using developed simulation platform
Collaboration with Industry: No.
Contact details:
Daily Supervisor: Dr. Jianning Dong ([email protected])
Supervisor: Prof. Pavol Bauer ([email protected])
35
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
LAB SETUP DEVELOPMENT FOR COURSE ET4291 CONTROL OF ELECTRICAL DRIVES
Type of project: Extra project (15 ECTS)
Scope: This project aims at development of a lab setup which can be used for laboratory work for course
ET4291 Control of Electrical Drives.
Problem definition: Currently there are only computer simulations available in the course ET4291 Control of
Electrical Drives, which does not meet the requirements of fast growing applications such as electric vehicles
and renewable energy. The extra project will develop a lab setup which enables implementation and
measurements of real life electrical drives for students. A permanent magnet synchronous machine and an
induction machine will be connected back-to-back. Two three-phase converters will be used to drive both
machines. One of the converters will work in torque control mode for generating. The other one will work in
speed control mode for motoring. Control algorithms will be developed with TI DSP and MATLAB/Simulink.
Methodology: First control blocks should be developed through hardware in loop simulation. Then interface
circuits between DSP and converters should be designed and implemented. Hardware implementation and test
of the system will be carried out afterwards.
Research Objectives:
Choice of components and system topologies.
Hardware in loop simulation of the drives.
Implementation of the lab setup.
Collaboration with Industry: No.
Contact details:
Daily Supervisor: Dr. Jianning Dong ([email protected])
Supervisor: Prof. Pavol Bauer ([email protected])
36
D C E & S
DC Systems, Energy Conversion & Storage
Electromechanics and Electric Mobility DC systems, Energy conversion & Storage
Master’s Thesis Proposal
PWM-INDUCED LOSSES IN FLOODED GENERATORS FOR TIDAL TURBINES
Type of project: MSc thesis
Stator can
Rotor can
Sea water
Scope: The project is an ideal opportunity for any student who wishes to understand how turbine
characteristics affect the generator performance and vice-versa. Flooded generators are proposed as a solution
to improve the reliability in tidal turbines. Materials, such as stainless steel , when used as a can experience
additional eddy current losses in the cans. Can losses may be significantly influenced by the PWM harmonics
introduced by the converter controlling the generator speed.
Problem definition: Estimate the can loss contribution to the total power loss in the flooded permanent
magnet generator. The can losses should account for the influence of the variation in tidal current velocity due
to the turbulence in the sea state.
Methodology: A tidal turbine experiences wide speed fluctuation about the reference speed due to low inertia
of tidal turbines and turbulence in tidal current velocities. The speed fluctuations can be calculated by coupling
the generator model (could be finite element, depending on the preference of the student) to the turbine
mechanical model e.g. in MATLAB Simulink. The speed control of the generator/turbine is achieved by using a
pulse-width modulated back-to-back converter. The model developed to estimate can losses must be used to
understand important can loss characteristics and trends, dependency on other system parameters, and
suggest ways to mitigate these losses.
Research Objectives:
Develop models to calculate the eddy current losses in a Canned machine.
Account for losses due to dynamic speed variations caused by turbulence in the sea state.
Influence of turbine and machine parameters, and the control strategies on the can losses.
Collaboration with Industry: Yes
Contact details:
PhD candidate: Faisal Wani, [email protected]
Supervisor: Dr. Jianning Dong, [email protected]
37
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
CONTROL OF DC NANOGRID CLUSTER BUILT WITH MULTI-PORT CONVERTERS
Type of project: MSc thesis
+ 350 Vdc -350 Vdc
MPC #1
PV system
EV
DC House #1
MPC #2
PV system
EV
DC House #2
MPC #n
PV system
EV
DC House # n
Figure[1]: (a)Quad-active Bridge Architecture and, (b) 4-legged transformer
Scope: Research on DC buildings and houses is gaining momentum in recent literature. Multi-port converters
(MPC )integrating multiple sources and loads are designed to realize the dc nanogrids as shown in Fig. 1(b).
Connecting the DC houses with MPCs to the utility grid can be an interesting research topic.
Problem definition: The research challenge in this field is to device a hierarchical control strategy for clustering
the DC nanogrids to form a resilient and reliable DC microgrid.
Methodology: The methodology to arrive at a good design are the following:
Literature review on control of nanogrid clustering
Control model of the DC bi-polar nanogrid cluster and the QAB converter
Research Objectives: The pertinent research objectives are highlighted below:
Combining the dynamic model of the MPC and the DC nanogrid cluster
Analysis of the resilience and availability of the dc grid
Energy management optimization to reduce operational cost
Collaboration with Industry: No
Candidate details:
PhD student: S. Bandyopadhyay [email protected] LB 03.640, Nils van der Blij [email protected] LB 03.690
Supervisor: Dr. Laura Ramirez Elizondo [email protected], LB 03.570 , Prof. Pavol Bauer [email protected] , LB 03.600
38
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
DESIGN OPTIMIZATION OF HF TRANSFORMER FOR A MULTI-PORT CONVERTER
Type of project: MSc thesis
Figure[1]: (a)Quad-active Bridge Architecture and, (b) 4-legged transformer
Scope: DC residential grids consist of multiple sources and bi-directional loads. An integrated multi-port
converter, which utilizes a single power conversion stage to interconnect all ports, instead of the individual dc-
dc conversion stages, can be introduced in order to make the whole grid simpler. Thus, cost, size, and volume
can be reduced due to less amount of devices and associated circuits. The reduced conversion step results in
higher power density and efficiency.
Problem definition: The research challenge in this field is to optimally model and design the high frequency
transformer to couple all the windings of the QAB converter.
Methodology: The methodology to arrive at a good design are the following:
3D and 2D FEM model of the transformer
Detailed loss model and evaluation power density limits of the transformer
Research Objectives: The pertinent research objectives are highlighted below:
A simplified equivalent circuit of the HF transformer
Loss model of the HF transformer
Multi-objective optimization and laboratory implementation
Collaboration with Industry: No
Candidate details:
PhD student: S. Bandyopadhyay [email protected]
Supervisor: Prof. Pavol Bauer [email protected] , LB 03.600
39
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
DC-GRID DESIGN FOR LOW-VOLTAGE DISTRIBUTION
Type of project: MSc thesis
Scope: Investigate and develop a dc-grid design based on current and future converter technologies.
Problem definition: DC grids play an important role in the energy transition as they allow the connection of
renewable energy sources, storage batteries and large consumers such as heat pumps and electric vehicles to
the grid in a single conversion step. This reduces the capital cost of the devices, increases the conversion
efficiency and allows flexible power management. However, standards are currently lacking, resulting in
different voltage levels and grid configurations for the implemented pilot projects. A wide range of possible
solutions makes it hard to come up with a concessive grid design.
Methodology: The goal of the thesis is to investigate and develop a dc-grid design. The design has numerous
degrees of freedom such as the voltage level and configuration (from bipolar 350 V to unipolar 1,5 kV), the
maximal length of the feeders, the integration of distributed or central storage to reduce load and generation
peaks etc. An important factor is the choice of the converter, both contemporary IGBT-based converters with
low-frequency insulation transformers and SiC-converters with high frequency transformers should be
considered. The grid is developed for several scenarios such as a distribution grid for residential connections, as
well as an industrial environment with a much higher load duration and high PV penetration.
Research Objectives:
Cost-effective dc-grid design at high efficiency
Impact of voltage level and grid topology and losses and voltage profile
Impact of converter technology on grid topology and efficiency
Collaboration with Industry: Dynniq Energy
Contact details:
Company contact: Sven De Breucker ([email protected])
University: L. M. Ramirez-Elizondo ([email protected])
40
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
FORECASTING MODELS & THEIR IMPACT ON THE PERFORMANCE OF A DC HOUSE
Type of project: MSc thesis
Battery
Controller
EV
Loads
PVPV
Scope: The goal of this project is to 1) forecast the yield of PV system based on the past data; 2) decide the
system operation in the future; 3) study the forecasting impact of the performance on the DC house.
Problem definition: With the increasing penetration of PV power system into the DC house, the problem
caused by fluctuation and intermittency of PV power output draws more attention. And this will also affect the
load consumption, especially during the peak time. What’s more, the data of PV irradiance is extensive, so
finding out the best method to forecast is also fundamental, such as stochastic method, fuzzy logic method,
machine learning.
Methodology:
Extensive literature review on DC house and forecasting algorithms
Design System architecture including the PV sizing, battery sizing and load profile
Model of the designed DC house system
Research Objectives:
Find the most appropriate forecasting algorithm
Apply the forecasting algorithm to the designed system
Analyse case studiesbased on performance (efficiency) with and without forecasting
Collaboration with Industry: No
Contact details:
PhD student: Na Li, [email protected];
Nishant Narayan, [email protected]
Victor Vega Garita, [email protected]
Supervisors: Pavol Bauer, [email protected]
Laura Ramirez Elizondo,[email protected]
41
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
SYSTEM SIZING & IMPACT OF DEMAND SIDE MANAGEMENT ON THE OFF-GRID DC
HOUSE
Type of project: MSc thesis
Battery
Controller
EV
Loads
PVPV
Scope: Demand side management (DSM) can be used to improve the utilization and efficiency of renewable
energy, especially in some places where there is no access to electricity. The goal is to design an autonomous
household system, decide its size, study the demand side management strategy and its impact on the energy
system sizing for an off-grid DC house.
Problem definition: Considering a typical DC house includes PV, battery and smart controller and some loads.
Because the PV yield doesn’t match with the demand, especially during peak hours, it is very important to
allocate the energy generated by PV system appropriately.
Methodology:
Extensive literature review on DSM for an off-grid DC house
Study the DSM strategies and decide the best one for this system
Model the off-grid DC house system
Research Objectives:
Evaluate the system size including PV, battery and load profile
Apply the DSM strategy in the designed system
Analyse case studies: system performance and sizing with and without DSM
Collaboration with Industry: No
Contact details:
PhD student: Na Li, [email protected];
Nishant Narayan, [email protected]
Victor Vega Garita, [email protected]
Supervisors: Pavol Bauer, [email protected]
Laura Ramirez Elizondo, [email protected]
42
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
SELF-SUFFICIENT OFF-GRID DC-APPLIANCES WITH ENERGY STORAGE AS A MODULAR
SOLUTION FOR CLIMBING UP THE RURAL ELECTRIFICATION LADDER
Type of project: MSc thesis
Fig. 1 Energy ladder in the context of rural electrification
Scope: 1.2 billion people around the world lack access to affordable electricity. Energy access is not a binary
metric as regarded in the past, but consists of multiple levels of electricity demand at different levels of the so-
called rural electrification ladder.
Problem definition: Solar Home Systems (SHS) seem to be a promising off-grid solution to power the off-grid DC
appliances. However, the optimal system sizing of SHS become obsolete when users move up the electrification
ladder. Therefore a modular solution needs to be adopted, which could be in the form of self-sufficient off-grid
DC loads.
Methodology: The research mainly consists of optimizing the system size of SHS for various levels of
electrification with and without the use of self-sufficient appliances. The student will be involved in modelling
and simulating SHS on MATLAB for different scenarios.
Research Objectives:
Comparing the optimal system sizing with and without self-sufficient DC loads in the system
Quantifying the costs and benefits of having storage-integrated DC loads
Comparing the load modularity with other modular architecture options
Collaboration with Industry: No
Contact details:
PhD students: Nishant Narayan<[email protected]>
Supervisor: Zian Qin< [email protected]>
43
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
POWER FLOW CONTROL IN LVDC GRIDS USING LOCAL ENERGY STORAGE
Type of project: MSc thesis
Scope: The LVDC grid faces two major bottlenecks- protection and power flow control. At the TU Delft partially
rated power flow control converter was proposed. The converter is developed with the Fraunhofer-IISB to
achieve the state-of-the-art hardware. The scope of this project is development and application of the novel
control methods for the developed device.
Problem definition: The power flow control converter (PFCC) can be enhanced with a local storage. However,
in doing so the energy storage control problems are included in already complex control of the PFCC. The main
focus of this thesis will be to develop the control of the partially rated power flow control converter with local
energy storage.
Methodology: The student needs to familiarize with the power flow control in LVDC grids and associated
challenges. After developing the control models in Matlab/Simulink, the algorithms will be applied in the FPGA
and tested in the laboratory.
Research Objectives:
Literature review of the power flow control and energy storage in LVDC grids
Developing the control algorithms for the partially rated power flow control converter
Application & Testing of the developed control methods in the laboratory
Collaboration with Industry: Optional
Contact details:
PhD student: Pavel Purgat, [email protected]
Supervisor: Dr. Zian Qin, [email protected],
prof. Pavol Bauer, [email protected]
44
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
MODELLING, STABILITY, CONTROL AND MANAGEMENT OF DC DISTRIBUTION GRIDS
Type of project: MSc Thesis
Microgrid
MicrogridNanogrid
Energy Storage System
Renewable Energy Sources
Electrical Loads
Fault Isolation Device
Microgrid
MV Grid
~
Scope: To aid the broad adoption of DC distribution grids more research is required on the modelling, stability,
control and management of dc distribution grids. Many topics within these categories are available for master
students.
Problem definition: Distribution grids are subjected to changes such as the increasing participation of
distributed energy resources (DER), segmentation of the grid, and increasing participation of consumers and
producers. This poses significant challenges with respect to stability and control. It becomes attractive to
employ DC distribution systems since they have several advantages to AC distribution systems. DC distribution
grids do not require the synchronization or reactive power governance, and do not have issues with harmonic
and inrush currents. Moreover, the interconnection of dc (micro)grids is significantly simpler. Furthermore, dc
distribution grids are also foreseen to have advantages over ac in terms of efficiency, distribution lines, and
converters .
Methodology: These topics mainly involve literature research, analytical derivations, simulations and/or
programming. However, design/experimental topics are also available.
Examples of available topics are:
Steady state (load flow) analysis of DC distribution grids
Transient analysis of DC distribution grids
Small-signal stability of DC distribution grids
Centralized/Decentralized/Distributed control of DC distribution grids
Demand Side Management in DC distribution grids
Cost of Flexibility in smart grids
Blockchain for Smart Grids
Collaboration with Industry: In some cases possible.
Contact details:
PhD student: Nils H. van der Blij ([email protected])
Supervisor: Laura M. Ramirez-Elizondo ([email protected])
Prof. Dr. Eng. Pavol Bauer ([email protected])
45
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
DESIGN AND EXPERIMENTAL VERIFICATION OF DC DISTRIBUTION GRID CONTROL
Type of project: MSc Thesis
Scope: It is essential for the broad adoption of DC distribution grids to design and experimentally verify the
research done on the modelling, stability, control and management of DC distribution grids. Different projects
are available to design converters or do experimental work.
Problem definition: Distribution grids are subjected to changes such as the increasing participation of
distributed energy resources (DER), segmentation of the grid, and increasing participation of consumers and
producers. This poses significant challenges with respect to stability and control. DC distribution grids are
foreseen to have advantages over ac in terms of efficiency, distribution lines, and converters . However, more
theoretical and experimental work is required to research and prove these advantages.
Methodology: These topics either mainly involve the design of suitable converters and/or the execution of
experiments. Moreover these projects entail literature research, simulations and programming.
Examples of Research objectives:
Design of a DC distribution system
Design of the communication between power electronic converters
Simulation of DC distribution systems
Conduct experiments regarding the control of DC distribution grids
Converter (PCB) design
Programming power electronic converter’s microcontroller
Collaboration with Industry: In some cases possible.
Contact details:
PhD student: Nils H. van der Blij ([email protected])
Supervisor: Laura M. Ramirez-Elizondo ([email protected])
Prof. Dr. Eng. Pavol Bauer ([email protected])
46
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
BATTERY MANAGEMENT STRATEGIES
Type of project: MSc thesis/Extra Project
Fig. 1 Battery management system board (left), and battery tester (right).
Scope: Energy Storage, especially batteries, have become an indispensable part of sustainable energy systems.
From PV Systems and Electric Vehicles to grid-scale applications, batteries play a vital role.
Problem definition: Batteries are often the first components to fail in an energy system, owing to short
lifetimes and demanding, complex trade-offs in their operational parameters. A battery management system
(BMS) needs to be designed for the most common battery technologies like Lead-acid gel, and Lithium Iron
Phosphate. The BMS should be capable of achieving controlled voltage balancing across the different battery
cells. Consequently, capacity fading rates can be observed.
Methodology: The research consists of firstly understanding the operational battery parameters and their
interdependencies. Secondly, the student will use dedicated hardware for BMS implementation, including TI
board (EM1401), and Arbin battery tester (LBT22043). Additionally, the student will devise test-case patterns
for charging and discharging the battery, along with implementation of Ah-counting through the available
hardware.
Research Objectives:
Develop test-case patterns for charging and discharging different batteries.
Implement Ah-counting and controlled voltage balancing for the different battery cells.
Analyse the expected different capacity fading rates between battery technologies.
Collaboration with Industry: No
Contact details:
PhD students: Yunhe Yu, Victor Vega-Garita, Nishant Narayan
Supervisor: Zian Qin < [email protected]>,
Pavol Bauer, <[email protected]>
47
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
DC Grids and Storage for Smart Cities DC systems, Energy conversion & Storage
LEARNING WITH THE BATTERY MANAGEMENT SYSTEM
Type of project: Extra Project/ SIP 2
Scope: The available battery cells and battery management circuit in the lab can be used to obtain the
knowledge of battery management system
Problem definition: Battery cells are always connected in series for a higher terminal voltage. Due to the
inconsistencies of the battery cells in terms of impedance, status of health (SOH), self-discharging, heat
dissipation, a battery management system is necessary to make sure the load is properly shared among the
cells and thereby maximize the lifetime of the entire battery stack.
Methodology: Laboratory work is expected
Research Objectives:
Build up the platform to test the battery management system
Able to control the charging/discharging current of the battery stack
Able to observe or estimate the parameters of the batter cells, e.g. capacity, state of charge,
temperature
Collaboration with Industry: <No>
Contact details:
PhD students: Yunhe Yu, Nishant Narayan, Victor Vega Garita
Supervisors: Zian Qin, <[email protected]>
Pavol Bauer, <[email protected]>
48
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Systems DC systems, Energy conversion & Storage
DISTRIBUTION GRIDS WITH FLEXIBLE DC LINKS
Type of project: MSc thesis
Scope: The existing ac link between two substations needs to be converted to partial dc link system2. Think of
how to interconnect the system to have maximum infrastructural utilization and showcase the operational
modes of the new system3. Provide grid support to the distribution network using this flexible ac-dc link.
Problem definition: Design and simulate a grid integrated flexible dc link for power redirection, reactive power
support, harmonic elimination and other ancillary services to improve the operability of the existing medium
voltage ac distribution network.
Methodology: Ability to simulate state space model and control strategies in MATLAB is required.
Understanding of modular multilevel converters (MMC) is to be developed. Enthusiastic student may use the
available laboratory prototype of MMC to implement his/her findings.
Research Objectives:
Show how parallel ac-dc link topology can operate with converter based voltage regulation.
Develop various grid supporting ancillary services using MMC, such as active power redirection,
reactive power support, fault ride through, harmonic elimination, etc.
Prove the working of the developed optimal ac-dc load sharing algorithm.
Analyse the proposed system feasibility with an economic/functionality study.
Collaboration with Industry: <No>
Contact details:
PhD student: <A. Shekhar, [email protected]>
Supervisor: <L. M. Ramírez-Elizondo, Pavol Bauer>
2 Aditya Shekhar, Epameinondas Kontos, Laura Ramírez-Elizondo, Armando Rodrigo-Mor, Pavol Bauer, Grid capacity and efficiency
enhancement by operating medium voltage AC cables as DC links with modular multilevel converters, In International Journal of Electrical Power & Energy Systems, Volume 93, 2017, Pages 479-493, ISSN 0142-0615, https://doi.org/10.1016/j.ijepes.2017.06.012. 3 Aditya Shekhar, Epameinondas Kontos, Laura Ramírez-Elizondo and Pavol Bauer, “AC Distribution Grid Reconfiguration using
Flexible DC Link Architecture for Increasing Power Delivery Capacity during (n-1) Contingency,” IEEE SPEC, 2017.
Outer
Substation AInner City
Substation B5-20 km
Operate the Overloaded MVAC
Underground Cable Under DC Conditions
MV/LV
Radial In-city
Distribution
<
Photograph>
49
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Systems DC systems, Energy conversion & Storage
SMALL-SIGNAL ANALYSES FOR INVESTIGATING SLOW CONTROL INTERACTIONS BETWEEN
POWER ELECTRONIC ELEMENTS IN MODERN ELECTRICAL POWER SYSTEMS
Type of project: MSc thesis
Scope: Multi-infeed and interaction of power electronics
Problem definition: For reliably integrating power electronic elements in modern power systems, the interoperability of the elements with the network and amongst each other needs to be ensured. The wide range of potential interaction phenomena can only be covered by a bundle of complementary approaches.
In a first step Siemens has proposed a methodology to investigate slow control interaction phenomena of a single VSC HVDC with the network in the linearized state space of complex systems based on small-signal analyses, i.e. modal analysis (eigenvalues and eigenvectors of the state matrix, etc.) and linear analysis tools (Bode, Nyquist, etc.).
For this thesis the proposed method shall be refined and extended to “multi-infeed” configurations addressing the interaction of multiple power electronic elements.
MATLAB and Simulink will be employed for the analyses of the linearized differential equations.
Methodology:
Enhance and extend proposed methodology to multi-infeed configurations in MATLAB/Simulink
Research Objectives:
Evaluate and understand interaction of slow control functions
Identify potential controller interaction
Find risk factors for detrimental controller interaction
Collaboration with Industry: SIEMENS. Probably a 3 month internship + 6 month Thesis (Erlangen, Germany)
Contact details:
Company: Sebastian Höhn, [email protected]
University: Lucia Beloqui Larumbe, [email protected]
50
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Systems DC systems, Energy conversion & Storage
SMALL DC LINK SUBMODULE FOR MODULAR MULTILEVEL CONVERTERS
Type of project: MSc thesis
Scope: Studying the methods to achieve small dc link of the submodule for MMC.
Problem definition: The modular multilevel converter (MMC) is the key technology of high voltage direct
current (HVDC) that enables power transmission through an extra-long distance. The submodule in MMC, as a
single phase dc-ac inverter, inherently suffers from second-order power ripple, which needs a large dc link
capacitor bank to overcome passively. The large dc link composed of electrolyte capacitors is bulky, heavy and
with short life, it is therefore a crucial challenge especially when the number of the arm converters is
tremendous, e.g. 300.
Methodology:
Build the MMC model
Deploy different modulation strategies in the MMC
Compare the impact on power ripple of the submodule
Research Objectives:
Find out the modulation strategy that can achieve the lowest power ripple in submodule
Evaluate the feasibility of using hardware method to reduce the power ripple in submodule
Contact details:
PhD student: Aditya Shekhar ([email protected])
Supervisor: Dr. Zian Qin ([email protected]),
Prof. Dr. Eng. Pavol Bauer, ([email protected])
Large capacitor bank
51
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
ARBITRARY VOLTAGE WAVEFORM FOR INSULATION TESTING PURPOSE
Type of project: <MSc thesis>
Scope: <To determine the extra information that can be extracted about dielectric condition when arbitrary
voltage waveform is used for diagnostics, instead of traditional AC or DC voltage >
Problem definition: < Partial Discharge (PD) measurement and dielectric spectroscopy are powerful tools used
for diagnostic of high voltage equipment . PD and DS measurement are often done at AC 50 Hz sinusoidal
voltage. While there are a lot of study regarding this type of measurement, still a comprehensive figure about
the insulation condition cannot be derived out of these measurements. On reason is that only limited amount
of information related to dielectric aging state would be present in PD and DS measurement when they are
done using 50 Hz sinusoidal waveform. The goal for this project is to investigate PD and DS measurement using
arbitrary voltage waveform and on oil-impregnated paper insulation to investigate whether it is possible to
extract valuable information about aging state of the paper insulation.
Methodology: <The work is mostly experimental work which has to be carried out at high voltage laboratory.
PD and DS measurement will be performed at different arbitrary voltage waveform and the measurement
results should be compared with AC 50 Hz voltage waveform>
Research Objectives:
<literature review of PD and DS measurement techniques>
<preparation of experimental set-up for investigation of aging status of oil-impregnated paper,
including how to generate arbitrary high voltage waveform, and how do PD and DS measurement >
<comparison of PD and DS measurement between arbitrary voltage waveform and AC 50 Hz>
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
Xiaolei Wang, “Partial Discharge Analysis of Stator Insulation at Arbitrary Voltage Waveform Stimulus”, PhD thesis, 2015
52
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
FEASIBILITY STUDY OF TRANSFORMER NOISE MAPPING BY MEANS OF VIDEO/IMAGE
PROCESSING>
Type of project: <Extra project>
Scope: < In this project feasibility study of transformer noise mapping using video files and image processing
techniques should be investigated.>
Problem definition: < A video file captured of an object can reveal significant amount of information about that
object. These information can be extracted if proper image processing technique is used. Recently it has been
shown that vibration of overhead line conductor can be extracted using signal processing of captured video
files from a vibrating conductor. Noise generated from a transformer can be used as a diagnostic tools to assess
the performance of the transformer. High amount of acoustic noise can also be disturbing for the people living
nearby a substation and hence requires action to reduce the noise level. Acoustic noise measurement and
creation of a noise map for a transformer is therefore of interest. Conventionally this is done by means of
microphone that are moved around the transformer and a colour map representing the magnitude of the
noise with respect to the location of the noise is created. This kind of map can be used to interpreting the
reason behind high amount of noise and possible active damping arrangement to suppress the disturbing
acoustic noise in the environment. Acoustic noise generated by a transformer is equivalent to vibration of the
transformer body. This vibration is different at different locations on the transformer tank. This subtle vibration
can be extracted out of colour change of a video file taken from the transformer.>
Methodology: <The work mostly involves MATLAB coding and video/image processing. An algorithm should be
developed to extract tiny motion through colour change of images in a video files. Simple experimental setup
with known noise sources will be used to test the developed algorithm>
Research Objectives:
<literature review of available motion magnification techniques>
<Development of a motion magnification algorithm suitable for extraction of tiny colour changes in an
image and verification of the code through experiment>
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Source: http://electrical-engineering-portal.com/transformers-are-never-silent
53
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
DIAGNOSTICS AND MONITORING OF HVDC CONVERTER TRANSFORMER
Type of project: <MSc thesis>
Scope: <To understand aging mechanism of oil-impregnated paper exposed to DC and AC stress at the same
time >
Problem definition: < Converter transformer is an important part of a HVDC link. Any unexpected failure of
such transformer can be very costly due to the cost of transformer itself and the cost of power interruption.
Condition monitoring of such transformer is therefore very crucial. To be able to properly interpret partial
discharge measurements recorded from a converter transformer it is necessary to understand how each
dielectric component inside a converter transformer behave to different stresses. Paper insulation inside a
converter transformer is stressed by DC and AC electric field at the same time while on a conventional
transformer the insulation is only stressed by AC electric field. Partial discharge behaviour of a converter
transformer is therefore different than a conventional transformer and hence the interpretation would be
different.
Methodology: < In this project life time of paper insulation material should be investigated under simultaneous
DC and AC electric stress. Evaluation of PD over the life time should be recorded and interpretation of the
results must be provided.>
Research Objectives:
<literature review of insulation system used in HCDC converter transformer and a summary of
available tests used to ensure a proper made converter transformer >
<Life time of oil-impregnated paper stressed with AC, DC and combined AC and DC stresses>
<Experiment of Impulse breakdown strength when oil-impregnated paper is aged with AC voltage
superimposed with pulsed stresses>
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
Source: ABB
54
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
ELECTRIC & MAGNETIC FIELDS ON HYBRID OVERHEAD TRANSMISSION LINES
Type of project: MSc Thesis
Scope: Analysis of the electric and magnetic fields on hybrid overhead transmission lines with the help of Finite
Element Methods.
Problem definition: One challenge, while designing hybrid overhead transmission lines, i.e. tower structures
that consist of both HVAC and HVDC circuits, is the combined effect of the electric and magnetic fields along
the line route.
Methodology: This project would include a) a literature review and b) basic simulation of electric and magnetic
fields with the help of Finite Element Methods and modelling in COMSOL Multiphysics software package.
Research Objectives:
Literature review and incentivization of applied standards worldwide;
Modelling of electric and magnetic fields in COMSOL Multiphysics.
Collaboration with Industry: Yes
Contact details:
Company: Konstantinos Velitsikakis, [email protected]
University supervisor: Peter Vaessen, [email protected]
Mohamad Ghaffarian, [email protected]
55
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
DESIGN OF A CONTROL SYSTEM FOR PARTIAL DISCHARGE ONLINE MONITORING OF
HVDC GAS INSULATED SYSTEMS
Type of project: MSc Thesis
Scope: To design a control system for continuous online monitoring of partial discharges for offshore HVDC GIS
substations, including the design of special algorithms for signal processing and automatic configuration of the
acquisition parameters.
Problem definition: partial discharges are one of the most efficient ways to monitor the insulation condition of
HVDC Gas Insulated Systems (GIS). Due to renewable energy integration, offshore HVDC substations are
increasing in number and power delivery. Remote online monitoring systems are crucial for the early detection
of insulation defects which can lead to faults and ultimately cause big economic, social and environmental
losses. Remote monitoring systems must be able to operate autonomously. For that purpose, signal processing
is used to extract information from the collected data. New algorithms and control strategies need to be
developed for an automatic and reliable operation of remote monitoring systems.
Methodology: This project includes: a) literature review; b) design of algorithms and control strategies; c)
implementation on acquisition systems using Labview software; d) high voltage experiments for validation.
Research Objectives:
Review of existing signal processing methods of noisy signals.
Development of adaptive algorithms for automatic trigger level determination.
Efficient implementation of algorithms in embedded control systems using Labview and control of fast
acquisition oscilloscope cards.
Verification of the system performance by means of high voltage tests.
Contact details:
University supervisor: Armando Rodrigo Mor, [email protected]
Luis Carlos Castro Heredia, [email protected]
Fabio Muñoz Muñoz, [email protected]
56
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Diagnostics and Monitoring DC systems, Energy conversion & Storage
DESIGN OF ALGORITHMS FOR AUTOMATIC DISCRIMINATION OF NOISE AND PARTIAL
DISCHARGE SIGNALS.
Type of project: MSc Thesis
Scope: To design algorithms for automatic discrimination of noise and partial discharge signals to be used in
autonomous and remote online partial discharge monitoring systems.
Problem definition: partial discharges (PD) are one of the most efficient ways to monitor the insulation
condition of high voltage assets. Online monitoring systems are used for continuous monitoring of equipment
for long periods of time, ranging from weeks to years. Nowadays, all the existing systems require human
supervision since measurements are heavily affected by noisy signals and external interferences. The lack of
algorithms for automatic discrimination of pulses hinder the expansion of autonomous and reliable monitoring
systems. Therefore, new signal processing tools are needed to be able to discriminate real PD pulses from noise
pulses and any other source of external interference. This research project focuses on the creation of an
algorithm for reliable discrimination of partial discharge pulses based on their shape and frequency
components. Development of algorithms based on machine learning, neural networks, fuzzy logic and other
advanced processing tools is expected.
Methodology: This project includes: a) literature review; b) design of algorithms; c) implementation of
algorithms on acquisition systems using Labview software and/or Matlab; d) high voltage experiments for
validation.
Research Objectives:
Review of existing signal processing methods for PD discrimination.
Development of algorithms for automatic recognition of PD pulses.
Efficient implementation of algorithms in embedded control systems using Labview and/or Matlab.
Verification of algorithms performance by means of high voltage tests.
Contact details:
University supervisor: Armando Rodrigo Mor, [email protected]
Luis Carlos Castro Heredia, [email protected]
Fabio Muñoz Muñoz, [email protected]
57
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
BREAKDOWN MECHANISM OF HIGHLY VISCOUS DIELECTRIC LIQUID
Type of project: <MSc thesis>
Scope: <The scope of this thesis is to model pre-breakdown phenomenon occurring in highly viscous dielectric
liquids >
Problem definition: <Streamer formation is the pre-breakdown mechanism in dielectric liquids. Based on the
applied voltage it can be classified as positive or negative streamer. Mechanisms of breakdown is different for
each of the streamer type. In the case of negative streamer, streamer is initiated due to formation of
microbubbles adjacent to the needle tip. The bubble itself forms subsequence to a current pulse injected to the
liquid due to an electronic avalanche. The current pulse create a high temperature zone inside the dielectric
liquid which vaporizes the liquid and forms the micro bubble. The bubble would further expands and reach a
maximum size. Thereafter the bubble contracts and vanishes. Due to columbic and electrophoretic forces the
bubble may detach from the needle tip and float into the liquids. Current pulses recorded from the negative
polarity shows a pulse train typically increasing in magnitude. The goal of the project if to simulate these
complex, Multiphysics phenomenon. >
Methodology: <The work include initial laboratory measurement in which corona discharge on a point-plane
geometry immersed in the dielectric liquid must be recorded at positive and negative voltage polarity with fast
and slow detection systems. A FEM model that simulate the pulses of corona discharges has to be developed >
Research Objectives:
<literature review of existing theory and publication about breakdown mechanism of dielectric liquids
and simulation methods that have been used>
<experimental work to record corona discharge under positive and negative polarities which slow and
fast detection circuit>
<Development of a FEM model that simulate the pre-breakdown phenomenon >
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
Source: Henrik Frid, et al. “Simulation of Microbubbles…”
58
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
DESIGN OF A CAPACITIVE VOLTAGE PROBE FOR SURFACE CHARGE MEASUREMENT
Type of project: <MSc thesis>
Scope: < A capacitive voltage probe for measurement of surface charges has to be designed and constructed.
The device will be used to experiment charge decay on surface of different dielectrics. A model representing
the phenomena of charge decay should be developed and verified with the experimental results.>
Problem definition: <Surface charges may accumulate on the surface of DC insulator and alter electric field
distribution. In gas insulated substations due to field emission from the enclosure, electric charges are injected
to SF6 and deposits on the surface of the spacer. In outdoor polymeric insulator surface charges are formed on
the insulator due to corona activity. The presence of surface charges may decrease the breakdown strength of
the insulator, leading to failure of HVDC component (in the event of lightning impulses) and hence interrupting
power transmission. Therefore understanding how surface charges form and decay on the surface of insulator
is very important for HVDC insulation design. >
Methodology: <The work consist of design and construction as well as simulation and experimental validation.
Experimental work will be done in high voltage laboratory with the help of constructed capacitive probe.
Simulation should be performed with COMSOL Multiphysics>
Research Objectives:
<to understand how electric charge and surface potential can be measured >
<To design a circuit capable of measuring surface potential due to surface charges, verification with
circuit analysis software (e.g. PSPICE)>
<construct the capacitive voltage probe>
<experimental work and measurement of surface charge decay on different insulation>
<development of a FEM model to simulate surface charge decay phenomena>
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
Xiaolei Wang, “Partial Discharge Analysis of Stator Insulation at Arbitrary Voltage Waveform Stimulus”, PhD thesis, 2015
59
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
MODELLING OF CHARGE DECAY IN HVDC CABLES
Type of project: <MSc thesis>
Scope: <To develop a model that can demonstrate charge decay and recovery voltage phenomenon on HVDC
cables >
Problem definition: <Space charges can accumulate in DC cables and alter the electric field distribution in the
cable. Space charge build up and decay depends on insulation parameters, temperature, and environment.
Charge decay can happen very quick or can take many days. When voltage is removed from a DC cable, trapped
space charges can remain in the insulation for a long time. A de-energized cable can therefore develop
potential difference between conductor and the sheath due to the available space charges. This is important
from the safety point of view as such electric potential can be lethal. In this project a finite element model and
a circuit model will be develop to demonstrate how the potential decay occurs when the voltage is removed
from the cable. The model must be validated by means of experiment.>
Methodology: <The work consists of development of a numerical model that can simulate charge decay and
voltage recovery phenomenon in HVDC cables. The work also involve experimental work which will be done in
high voltage laboratory. >
Research Objectives:
<literature review of mechanism of charge decay and voltage recovery measurement as a diagnostic
method>
<Development of a FEM model in COMSOL Multiphysics that simulate charge decay in HVDC cable.
Development of a circuit model that can represent voltage recovery phenomenon>
<Comparison of the developed model with experiment>
Collaboration with Industry: < No>
Contact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
E. Kuffel, W et al, High Voltage Engineering Fundamentals.
60
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
MODELLING OF A FAST ACTUATOR FOR HVDC BREAKER APPLICATION
Type of project: <MSc thesis>
Scope: <Development of a FEM model that accurately predicts operation of a Thomson coil >
Problem definition: <To interrupt HVDC current three main technologies are available. In the first technology
power electronic switches are used to interrupt the current. This technology offers a very fast operation (~1𝜇𝑠)
however the on-state loss is rather high which makes the technology expensive to operate. The second
technology is purely mechanical. The on-state loss for this technology is minimized but the operation time of
the switch is rather high (~60m𝑠). In the third technology a combination of both methods are used in which the
on-state operation has almost a minimal loss while the operation time is reduced significantly (~5m𝑠)
compared to purely mechanical switch. To achieve an ultra-fast actuation a Thomson coil can be used. The coil
is connected to a capacitor bank and the armature is connected to the breaker push-pull rod. By discharging
the capacitor bank through the coil, the armature experienced a force which moves it away from the coil. The
phenomenon involves number of physics that are coupled. Electromagnetism, heat transfer, Newton motion
laws, and solid state mechanic equations. The involved physics must be solved together in order to accurately
model the behaviour of the actuator.>
Methodology: <The work is mostly focused on computer simulation. After development of the model, a small
scale Thomson coil has to build to verify accuracy of the constructed model. The experimental part will be done
in high voltage laboratory of TU Delft.>
Research Objectives:
<literature review of the existing HVDC circuit breaker mechanisms and understanding operation
cycle of each method >
<To be able to couple different physics in COMSOL Multiphysics software>
<Development of a FEM model that can accurately predict the operation of a Thomson coil>
<experimental verification of the constructed model on a small scale Thomson coil>
Collaboration with Industry: < No>
C ontact details:
Supervisor: < Mohamad Ghaffarian Niasar, [email protected]>
Rob Ross, [email protected], Peter Vaessen [email protected]
Magnus Callavik et al, Hybrid High-voltage Direct Current Breaker
61
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
MODELLING OF SUPERCONDUCTING TAPES AND CABLES
Type of project: <MSc thesis>
Scope: < The scope of this project is to develop a finite element model for calculating AC losses in the
superconducting tape with different tape size and cable design. >
Problem definition: < Superconductors are materials that can conduct a stationary electrical current without
resistance. Alternating magnetic fields and transport currents cause dissipation of energy in superconductors.
The energy dissipation is called AC loss. The magnetic field penetrates the material in the form of flux lines. The
magnetic-field variation inside the material induces an electric field E according to Faraday’s law. The electric
field drives “screening currents” in the material. The screening currents determine the magnetic-field
distribution in the superconductor according to Ampere’s law. The screening currents dissipate energy given by
E.J. The energy is delivered by the external magnetic field and is supplied by the power source which generates
the magnetic field. The energy is required for depinning and moving the flux lines, which is a dissipative
process. The energy is converted into heat that must be removed by the high cost and low efficiency cooling
system. AC loss is therefore an undesirable phenomenon.>
Methodology: < The research is included the modelling of the cable in COMSOL Multiphysics® software and
calculating the AC loss (the energy which is required for depinning and moving the flux lines).>
Research Objectives:
< Model the superconducting cable in COMSOL Multiphysics® software.>
< Calculating the AC loss and validating with the available publications.>
< Reducing the AC loss by changing the configuration of the superconducting tapes.>
Collaboration with Industry: < No>
Contact details: Babak Gholizad, [email protected]
Mohamad Ghaffarian Niasar, [email protected]
Rob Ross, [email protected]
Source: Marijn Pieter Oomen, PhD thesis
62
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
BREAKDOWN STRENGTH OF SOLID INTERFACE WITH ARTIFICIAL DEFECTS UNDER
DIFFERENT AC WAVEFORMS
Type of project: < Extra Project>
Scope: The scope of this project is to investigate the breakdown strength of solid interface with artificial
defects under different AC waveforms.
Problem definition:
The largest part of the failures in the cable systems occurred in the cable accessories, especially at the interface
between cable insulation and accessory insulation. Defects might be introduced to the interface during the
installation process, or created at the interface due to the aging process. Beside the normal operating AC
voltage, the cable systems are also subjected to other types of AC voltage waveforms, such as the transient
over-voltage caused by switching or lightning impulses, or the AC sinusoidal waveforms with different
frequencies that are applied during after-laying tests, or the AC voltages with harmonics caused by power
electronics in the system. Degradation can be ignited or accelerated by such AC waveforms within the defects
at the interface, which will finally lead to breakdown. This work is to study the breakdown strength at the
interface with defects under the different types of AC waveforms.
Methodology:
this project will be mainly carried out in the high-voltage laboratory of TUD. AC voltage waveforms need to be
determined and generated. Material samples need to be prepared with introducing defects. Statistical analysis
will be performed after breakdown measurements.
Research Objectives:
To learn the different AC voltage waveforms that may stress on the cable accessories
To prepare the samples and fabricate the defects at the solid interface
To measure the breakdown strength of the samples and analyse the results
Collaboration with Industry: < No>
Contact details:
PhD student: Jiayang Wu [email protected]
Supervisor: Armando Rodrigo Mor [email protected]
63
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
PARTIAL DISCHARGE CHARACTERISTICS AT SOLID INTERFACE WITH ARTIFICIAL DEFECTS
UNDER SUPERIMPOSED VOLTAGES IN MATERIAL SCALE
Type of project: <Master Thesis>
Scope: The scope of this research is to investigate the characteristics of partial discharges at the interface of
cable insulation materials with defects under superimposed waveforms.
Problem definition:
Although the HV cable systems should be well designed in order to withstand operation and transient
conditions, failures may still occur especially in the cable accessories. It can be expected that many failures are
initiated by partial discharge activities within the defects, which are caused by installation or aging process.
Therefore, investigation of partial discharges can give useful information about the conditions of cable
accessories and predict the probable failures. On the other hand, impulse voltages caused by switching
operations or lightning strikes, can ride over the operating AC voltage to form the superimposed voltage, which
increase the stress on network components and may trigger partial discharges. Thus, a study on partial
discharge characteristics under superimposed voltages is needed in order to provide information for failure
prediction.
Methodology:
this project is focused on the partial discharge behaviour at the interface of cable accessories. Experiments
need to be performed in the high-voltage laboratory with generating superimposed voltage waveforms,
preparing material samples with defects and performing PD measurements.
Research Objectives:
To generate superimposed voltages (with switching and lightning)
To prepare the samples and fabricate the defects at the solid interface
To measure the partial discharge parameters of the samples
To analyse the results and interpret the mechanism
Collaboration with Industry: <TenneT>
Contact details:
PhD student: Jiayang Wu [email protected]
Supervisor: Armando Rodrigo Mor [email protected]
64
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
MODELLING ELECTROMECHANICAL INSTABILITY MODE IN ELECTROACTIVE POLYMERS
USING FINITE ELEMENT METHOD (FEM)
Type of project: Master Thesis (45 ECTS)
1 Electromechanical stress concentration (from S.Park,2012)
Scope: The scope of the project is to determine in which conditions the electromechanical instability (Pull-in
instability) failure occurs in dielectric elastomer that is typically used in artificial muscles or energy wave
harvesting.
Problem definition: Dielectric electroactive polymers (DEAP) are a class of smart insulating material used in
actuators or energy harvesting devices. When a DEAP membrane is exposed to high electric fields, it deforms
due to Coulomb forces created on its surface. This translates in transforming energy from an electrical domain
to a mechanical one. And vice versa, since reversibility of the process.
The applied force may not be homogeneous all over the surface due to localized stress concentration: these
areas are the weakest spots of the system. It is important to understand how these spots arise in order to
prevent this failure mode.
Methodology: The project includes: a modelling part in which the mechanical and electrical stresses are
coupled and described by a set of non-linear equations; a simulation part in which a standard finite-element
(FEM) discretization is used to evaluate the model on different 3D geometries. Research Objectives:
Designing a model that fully describes the electromechanical coupling of DEAP
Understanding conditions that make electromechanical instability failure mode occur
Collaboration with Industry: No
Contact details:
PhD student: Alessandro Iannarelli, [email protected]
Supervisor: Rob Ross, [email protected]; Pavol Bauer, [email protected]
65
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
PERFORMANCE REDUCTION STUDY OF ELECTROACTIVE POLYMER USED IN ENERGY
HARVESTING GENERATOR OR ARTIFICIAL MUSCLES
Type of project: Master Thesis (45 ECTS)
Scope: The scope of this study is to determine the cause of performance reduction in energy harvesting
generator or artificial muscle due to repetitive and uninterrupted use.
Problem definition: Dielectric electroactive polymers (DEAP) are a class of smart insulating material used in
actuators or energy harvesting devices. When a DEAP membrane is exposed to high electric fields, it deforms
due to Coulomb forces created on its surface. This translates in transforming energy from an electrical domain
to a mechanical one. And vice versa, since reversibility of the process.
During its operation, such material undergo a huge number of deformation cycles. From previous experiments,
it has been observed that the actuation displacement for a DEAP system changes over time albeit the voltage is
kept the same. The actuation jump again back to its max when the device is kept at rest for some time. T make
a reliable and robust system that can work for long time continuously, it is important to know which are the
causes of this loss of performance in time.
Methodology: The project includes: quantitative observation of displacement change over time. This will done
both with visible and IR camera imaging ; Measurement of the conductivity of silicone thin film; Measurement
of possible space charges formation.
Research Objectives:
Quantify the speed of performance reduction over time.
Verify the possibility of space charge formation in thin silicone film.
Possibly understand the performance reduction cause and formulate a solution.
Contact details:
PhD student: Alessandro Iannarelli, [email protected]
Supervisor: Rob Ross, [email protected]; Pavol Bauer, [email protected]
66
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
DESIGN OF A COAXIAL SAMPLE FOR CALIBRATION AND CHARACTERIZATION OF SPACE
CHARGE ACOUSTIC MEASUREMENTS
Type of project: MSc thesis
Scope: Design of a sample resembling a full size HVDC cable, capable of emulating trapped electric charges at
different radius of the cable’s dielectric bulk. The calibrated sample should be compatible with the acoustic
methods used at Space Charge measurements.
Problem definition: HVDC networks are widely increasing their presence in the transmission network due to
the new developments and achievements of HVDC power converters. Therefore, measurement of the Space
Charge phenomena in HVDC components is becoming more relevant. The availability of different space charge
measurement methods brings the necessity of calibration and characterization of measurement equipment in
order to reach standardized measurements. This brings the necessity of a reliable calibrated sample to
reproduce the same charge values in different tests and equipment.
Methodology: The research involves full understanding of the acoustic methods for space charge
measurements. The student will make a design of the coaxial calibration sample and proceed to its
construction and validation tests.
Research Objectives:
Develop a design for a space charge calibration sample.
Construction and testing of the sample prototype.
Collaboration with Industry: No
Contact details:
PhD student: Guillermo Mier, [email protected]
Supervisor: Armando Rodrigo Mor, [email protected]
67
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
INTEGRATED ULTRASOUN SENSOR FOR THE CALIBRATION OF PRESSURE WAVE
PROPAGATION METHODS IN SPACE CHARGE MEASUREMENTS OF HV CABLES
Type of project: MSc thesis
Scope: Design a electroacoustic sensor that will be coupled to a HV cable sample during PWP measurements.
The use of this sensor should be capable of predict the measured space charge values at different trapped
charge values.
Problem definition: HVDC networks are widely increasing their presence in the transmission network due to
the new developments and achievements of HVDC power converters. Therefore, measurement of the Space
Charge phenomena in HVDC components is becoming more relevant. One of the challenges involving the
measurement of SC in HVDC cables is the need of a HV at the inner conductor for calibration purposes; which
brings the necessity of very long cables for the construction of terminations, as well as the incapacity of
measuring SC in post-mortem tests. The capacity to measure the propagating pressure wave at different points
of the cable allows to calibrate without the HV at the inner electrode.
Methodology: The research involves full understanding of the PWP method for space charge measurements.
Selection of the most appropriate sensor according to the electrical and mechanical requirements. The process
involves simulations and extensive laboratory work.
Research Objectives:
Selection and design of the sensor.
Validation of the design by laboratory testing.
Methodology to calibrate PWP method with the measured pressure waves.
Collaboration with Industry: No
Contact details:
PhD student: Guillermo Mier, [email protected]
Supervisor: Armando Rodrigo Mor, [email protected]
68
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
CELLULOSIC INSULATION IMPREGNATED WITH ENVIRONMENTALLY FRIENDLY LIQUIDS
USED IN LARGE POWER TRANSFORMERS AND REACTORS.
Type of project: MSc thesis
Scope: Study on the lightning impulse withstand properties of transformer insulation impregnated with
environmentally friendly liquids.
Problem definition: Due to the efficiency and durability, a modern power transformer is one of the most
sustainable elements of the power system. The market demands as well as legal regulation force the increase
in using environmentally friendly materials in the high voltage components. Royal SMIT Transformers considers
replacing the mineral oil by the environmentally friendly liquids (esters) in the produced power transformers.
On the one hand, such action would decrease the environmental footprint of the produced transformers even
more. On the other hand, it must be ensured that the use of new insulating liquid will not jeopardize the
reliable operation of the transformer for the period of e.g. 40 years. The proposed research will be the first
step to verify the latter.
Methodology: The investigation will consist of both theoretical and practical parts:
Literature study on the breakdown phenomena and withstand capabilities of esters.
Lightning impulse testing of the inter-turn insulation impregnated ester.
Statistical analysis and comparison of the obtained values with those obtained for mineral oils
(reference to the previous research, e.g. MSc thesis of A. Ionut – TU Delft, 2011)
Research Objectives:
Define the withstand capabilities of cellulosic insulation impregnated with ester.
Compare the breakdown characteristics of mineral oil to the properties of ester when considering the
two liquids as impregnating medium for high voltage transformers.
Collaboration with Industry: Royal Smit Transformers
Contact details:
Supervisor SMIT: Lukasz Chmura, [email protected]
Supervisor SMIT: Maarten Deutekom, [email protected]
TUD Supervisor: Armando Rodrigo Mor, [email protected]
69
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
LIGHTNING IMPULSE PROPAGATION WITHIN A NEW TYPE OF WINDING– STEP 1.
Type of project: MSc thesis
Scope: Study on the lightning voltage distribution in the next generation of transformers and reactors.
Problem definition: Part of the factory acceptance test for extra high voltage transformers and reactors is
Lightning Impulse (LI) testing. During such test, the voltage distribution along the winding depends on electrical
parameters of the winding (capacitance, inductance and resistance). The later, in turn, are related to the
physical dimensions of the winding and the ratings of the transformer. It is widely known that the lightning
impulse voltage does not distribute linearly along the winding. The challenge lies in understanding the details
of voltage distribution across the winding during the lightning impulse. As an example, a 230 kV reactor can
contain up to 2000 meters of copper wire per winding. Such length in combination with very short rise-time of
a lightning impulse might additionally introduce the travelling wave effect and oscillations within the winding.
Methodology: Major steps:
Literature study on the transient behaviour within transformer windings.
Inventory of parameters governing the voltage distribution along the winding during LI test.
Winding model development and simulation of the LI voltage distribution.
Measurement of LI voltage distribution on a real winding and model verification.
Research objective:
Develop a tool/model which will help to determine the LI voltage distribution along the winding of
when considering dimensions and number of turns differ.
Collaboration with industry: Royal Smit Transformers
Contact details:
Supervisor SMIT: Lukasz Chmura, [email protected]
Supervisor SMIT: Maarten Deutekom, [email protected]
TUD Supervisor: Armando Rodrigo Mor, [email protected]
70
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
INTEGRITY OF EARTHING GRIDS OF HIGH VOLTAGE SUBSTATIONS
Type of project: MSc Thesis
Scope: Modelling of earthing grids and developing a method to access the integrity of the earthing grid after it
has been installed and is operational.
Problem definition: Earthing system in substations are used to safely carry the short circuit currents in case of
faults to ground conditions. A properly designed earthing grid ensures that the ground and equipment
potentials remain within a safe limit. Earthing grids are made of a mesh of copper conductors buried under the
substation. Therefore, it becomes a challenge to assess the quality of an earthing grid after the system has
been installed. This project aims to the evaluation of various ways for assessing the integrity of an earthing grid
after it has been installed and is operational.
Methodology: This project would include a) a literature review, b) detailed simulation of cases in SES CDEGS
software package and c) field measurement(s) to verify the simulations.
Research Objectives:
Review of existing methods for assessing the integrity of earthing grids;
Modelling of substation earthing grids in SES CDEGS;
Verification of measurement results.
Contact details:
Company: Konstantinos Velitsikakis, [email protected]
University supervisor: Peter Vaessen, [email protected]
Mohamad Ghaffarian, [email protected]
71
D C E & S
DC Systems, Energy Conversion & Storage
Master’s Thesis Proposal
High Voltage DC Materials and Components DC systems, Energy conversion & Storage
MODULAR MULTILEVEL CONVERTER BASED ARBITRARY VOLTAGE WAVEFORM
GENERATOR FOR DIELECTRIC TESTING
Type of project: MSc thesis
Scope: To construct a MMC based arbitrary voltage waveform generator for dielectric testing purpose
Problem definition: Random wave shape generator can bring revolutionary change in the high voltage testing
techniques. For example, the partial discharge’s (PD) appearance and its specific features are greatly
influenced by the testing voltage waveform and frequency; this is because different physical processes may be
stimulated by different durations of the applied waveform. To be able to implement such diagnostics tool, the
first step is to design a generator capable of generating arbitrary voltage waveform. Voltage amplifier that can
generate arbitrary voltage waveform is already commercially available (up to 50 kV), however they are
expensive and the output power is limited. The idea of this project is to design and construct a MMC capable of
generating arbitrary voltage waveforms.
Methodology: To simulate, design and construct a MMC arbitrary voltage waveform generator
Research Objectives:
literature review of MMC technology, design, limitations, control methodology, etc.
to make a computer model for MMC capable of generating arbitrary voltage waveform
to construct a small scale (1 kV) MMC based arbitrary voltage waveform generator
Collaboration with Industry: Yes, DNVGL
Contact details:
Supervisors:
Mohamad Ghaffarian Niasar, [email protected]
Peter Vaessen, [email protected]
Source: Wikipedia