student poster competition 4 minute ‘elevator pitches’

Student Poster Competition

4 minute ‘elevator pitches’

www.smart-microgrid.ca

Project 1.1Study of Dynamic Characteristics of Autonomous Droop-controlled MicrogridsABOUTALEB HADDADI (McGill University)AMIRNASER YAZDANI (Ryerson University)BENOIT BOULET (McGill University)GEZA JOOS (McGill University)

Problem statement• A challenging task is to

regulate the voltage amplitude and frequency of an autonomous microgrid:– Multi-input multi-output

(MIMO), – Time varying, – Non-linear,– Considerable transient

and steady-state impacts imposed by loads.

Problem statement• Most commonly, the goal is achieved by coordinated control

of multiple Distributed Energy Resource (DER) units through droop-based control.

• Advantages:– Simple structure (use of SISO controllers),– Plug-and-play feature,– No need for communication between the DERs,– Enables power sharing.

• Challenges:– Sensitivity of control to droop gains,– Sensitivity of control to the steady-state power flow (real- and

reactive-power outputs of DGs),– Dependence of stability on the network and loads,– No control over transient performance.

Challenges of droop control - Example

• An induction machine load is connected to Bus 6 at s,

• The network becomes unstable following the connection of the induction machine load.

Example: Poor transient performance of droop-based control due to dynamic coupling between the DER units and loads in a droop-controlled autonomous microgrid � connecting an induction machine load to a test microgrid

Figure 1: The test microgrid.

• A 12.47-kV North american Distribution network, Autonomous mode of operation,

• Droop-based voltage and frequency control,

Figure 2: Response of the DERs to connection of an induction machine to the test microgrid showing poor stability of droop-based control due to dynamic coupling between the DER units and loads.

Fahimeh Kazempour and Reza Iravani

University of Toronto

A Robust Hierarchical Control Structure for

Virtual Power PlantsProject 1.2. Distributed and Hybrid Control

Problem Statement• Unlike the conventional grid-connected mode, a microgrid in

the Virtual Power Plant (VPP) mode of operation is obliged to: Exchange a specified active and reactive power at the PCC, Maintain PCC's voltage and frequency within specified values Provide dynamic power balance within the microgrid.

• A three-level hierarchical control structure needs to be employed to realize the VPP mode of operation.

• A VPP is subject to: Operating point changes, Parametric and topological uncertainties, and unmodeled

dynamics in both the local DERs and their interactions, Exogenous disturbances.

– At the primary control level, a robust control strategy is used to synthesize DER’s local controllers.

The Proposed Solution

• The method of decentralized robust H∞ control with integral quadratic constraint (IQC) uncertainty description is employed to develop dynamic reference-tracking controllers.

• Using this method, necessary and sufficient conditions are derived to: Guarantee the stability of the overall VPP system

Minimize the H∞-norm bound on a map from the disturbance input to the controlled output

• Our method only requires solving a set of game type algebraic Riccati equations

• Algebraic Riccati equations are presented in terms of rank constrained LMIs

• A suitable test system is employed, to investigate the robust dynamic performance of the VPP system under the proposed control structure.


Project 1.3Current State Estimation for MicrogridAhda P. Grilo, Pengfei Gao and Wilsun Xu (University of Alberta)

Current State Estimation for Microgrid

• Smart grids will increase load management opportunities for customers.

• For microgrids the real-time power consumption of loads is a useful information for energy management systems.

• In commercial facilities it is difficult to measure currents.

Idea: Voltages at the load terminals are often accessible and can be measured by distributed voltage sensors.


Proposed method: 1) To measure voltages at the load terminals by

distributed voltage sensors.2) Use these voltages, combined with the

network topologies and parameters, to estimate the load currents.

Traditional: Microgrid:


The proposed technique represents a good solution for microgrid facilities where the load conductors are inaccessible for current sensing.

The idea of using voltages to estimate currents as presented in this paper has some other applications. For example, it could be used to monitor home appliance behavior by using distributed voltage sensors installed at various locations of a home.

A Stochastic Simulation Tool for Studying the Electric Features of Micro-grid

Qingxin Shi and Ricardo Torquato, Department of Electrical and Computer Engineering, University of Alberta

The development of smart micro-grid requires a lot of planning and monitoring studies. Therefore we need to model the real-time performance of the micro-grid. The model should take into consideration all kinds of random factors, such as random behavior of home appliance and random power generation of photovoltaic (PV) panel. This poster presents a simulation platform to handle this work. The application of this platform is: to simulate the real-time network response of the random loads and random PV generation, helping the engineers to manage the micro-grid.


Project 1.3Contribution of DGs to fault current and their impacts on overcurrent Protection

H. YazdanpanahiPDS Lab, Department of Electrical & Computer Engineering, University of Alberta

Problem• In spite of their undoubted advantages,

DG units impact on over-current protection by contributing to fault current.

Nuisance (sympathetic) tripping

Net R

DG

Fault

F

DG

P1

Net

P2

Failure in fuse-saving scheme

A

Net.

Back-up Main

FaultDG

B

Current

Time (s)

If1

Back-up

Main

If2

Miscoordination between main and back-up

ResearchFour types of DGs have been investigated.

For each type, the magnitude and duration of the current is assessed by analysis and simulation from the perspective of relay coordination.

Inverter-based Synchronous Machine

PMSM

Mechanical torque

Rotor-side converter

Grid

Grid-side converter

DC link

Induction Machine


Project 1.4

Operational Strategies and Storage Technologies to Address Barriers for a Very High Penetration of DG Units in Intelligent MicrogridsMichael Ross (McGill University)Dr. Chad Abbey (Hydro-Québec)Professor Géza Joós

Point of Common Coupling- Limit power fluctuations- Reduce the peak power flow through PCC

Energy Storage System- Time-dependent resource- Limited by power and energy rating

Demand Response- Ability to curtail non-critical load.- Critical load must be supplied with

energy (high reliability)

Problem: Optimized Microgrid Dispatch with a Very High Penetration of Renewable Energy

Energy Storage System Non-Critical

LoadsDiesel Generator

Critical Loads

Electric Power System

Wind Generation

(50% penetration)

Solar Generation

(50% penetration)

Renewable Energy Distributed Generation- Fluctuating and variable power output- Power balance is difficult to achieve

Diesel Generator- High greenhouse gas emissions- Expensive fuel cost

Proposed Solution: Multi-Objective Optimization Dispatch for Microgrids

A Microgrid controller must be developed to coordinate the control of available Distributed Energy Resources (DER) to:• Minimize cost of energy• Reduce peak power through PCC• Minimize power fluctuations through PCC• Improve reliability• Reduce GHG emissions

The multiple benefits can be optimized while mitigating the adverse effects of renewable energy integration.


Project 2.1Cost-Benefit Framework: Secondary Benefits and Ancillary ServicesMIKE QUASHIE AND GEZA JOOS (MCGILL UNIVERSITY)

A Methodology to Optimize Benefits of Microgrids

• Objective:This paper proposes a generalized methodology to determine the optimal configuration of microgrids that maximizes its benefits.The technique proposed herein, incorporates an advanced modeling of variable loads and distributed generators into a power flow problem to solve the benefits’ optimization problem:

Subject to: (2)• …..(3)

The Methodology is applied to real feeder in north America.The study shows significant reduction in cost of energy which seek to advance the business case of microgrids . It also provides potential investors and stakeholders a planning strategy to maximize the benefits accrued from microgrids.

Figure 1. Cigre's North American medium Voltage Distribution Network Benchmark with DG connected to operate as Microgrid

A Novel Affine Arithmetic Method to Solve OPF Problems with Uncertainties in

Microgrids

Mehrdad PirniaClaudio Cañizares

Kankar Bhattacharya Alfredo Vaccaro

Department of Electrical & Computer Engineering

24

Motivation

• Increased focus on renewable generation has brought forth many concerns in planning and operation of microgrids.

• Margins of operation for thermal generators are needed to provide system reliability and efficiency in view of the variability brought about by DR and DG technologies.

• Common methods to consider uncertainties from renewable sources integration (e.g., Monte Carlo Simulation) rely on pdfs of random variables and are not efficient.

• Self Validated Computation Methods (SVC) do not need pdfs and are efficient: – Interval Arithmetic (IA)– Affine Arithmetic (AA)

Methodology and Results

• Develop an accurate and efficient AA-based OPF model to incorporate uncertainties in microgrids.

• Validate the AA-based operation system models with the MCS based method.

• Use the resulting AA based intervals to estimate the spinning reserve requirements in the presence of DR and variable DG penetration in microgrids.

• Test and validate the model on a benchmark microgrid.

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EFFECT OF PRICE-RESPONSIVE DEMAND ON DISPATCH AND COSTS IN

MICROGRIDS

Felipe Ramos-GaeteClaudio Cañizares

Kankar Bhattacharya

Department of Electrical & Computer Engineering

Motivation• With smart microgrids, loads in the grid are required to

react to stressful conditions of the system.

• Depending on load reaction, cost inefficiencies, line congestions and even energy shortage may occur.

• It is necessary to examine the effect of price-responsive demand on smart microgrid unit commitment of distributed generators and storage.

• In the long run, is also relevant to study the inter-relationship between demand elasticity and electricity prices.

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Methodology and Results

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• Develop models to represent demand response in dispatch.• Develop a microgrid unit commitment and dispatch model.• Establish a link between prices and customers’ response.• Some interesting findings:

– More elastic demand can make the system less stable, increasing or decreasing the demand beyond feasible operating points.

– Multi-period price-responsiveness presents a similar behaviour as energy storage systems, soothing system variability while minimizing total operation cost.

– A corrected real-time pricing scheme can be derived from this work, which would allow more controllability over demand response.


Stability and Control of Unbalanced Synchronous Machine Based Distributed GeneratorsEhsan Nasr Azadani, Claudio Canizares, and Kankar BhattacharyaDept. Electrical and Computer Engineering, University of Waterloo

Motivation• Rapid development and increase in penetration of

decentralized or distributed generation (DG).• Transition from a passive grid containing only loads to an

active grid, including loads and “small” generation.• The dynamics of both transmission and distribution system

are affected.• Lack of knowledge of the dynamics of DGs under

unbalanced conditions.• A full characterization of the unbalanced system in stability

analyses would allow a better understanding of dynamic behaviour of DGs.

• Most DGs nowadays are equipped with small synchronous generators (e.g., diesel generators, microturbines)

Objectives• Develop both static and dynamic models of synchronous-

machine DG under unbalanced conditions.• Perform:

– Voltage stability studies based on P-V and P-L curves.– Small perturbation stability studies using a model

identification approach to compute the eigenvalues.– Transient stability studies based on time domain

simulations to study contingencies.• Propose a control strategy to improve the stability of

distribution systems with synchronous-machine DG units.


Project 2.4Stochastic evaluation of transient stability of Micro-gridsMayssam Amiri, Ani Gole, Tomás Yebra Vega (University of Manitoba)

Stochastic evaluation of the stability in a Micro-Grid is more realistic and less conservative.

Model

Results

Wind turbine

PV

µ-turbine

Small SM

DG

µ-

Gri

dG

enera

tor

Math

eti

cal

SM 0.0 SM 2.1

sec 0.00 0.50 1.00 1.50 2.00 2.50

0

50

100

150

200

250

300

350

400 delta

sec 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

-40

-20

0

20

40

60

80

100 delta

Statistical approach

• 100’s or 1000’s of variables

• Closer to reality• Less conservative than traditional methodsMonte Carlo Method• Time consuming

Parallel Computing

Evaluation Probability of failure

caused by unstability

ModelProb.LLL & LLLG

Prob.LL & LLG

Prob.LG

SM 0.0

0.0367 0.104

70.155

4SM 2.1

0.0254 0.0250.001

3

• Discrimination type of Fault

• Influence of the mathematical model

• Influence of µ-Grid design.

• Influence of the degree of penetration of DG’s

PDF’s


Project 3.1 Universal Communication Infrastructure

Are Omnidirectional Terminal Station Antennas a Better Choice for Point to Multipoint Deployments in NLOS Environments?

Prof. David G. Michelson (University Of British Columbia)Sina Mashayekhi (PhD student)

Problem: Directional Antennas Performance in NLOS Multipath Environment

• Minimum requirement for P2MP radio systems for management of the electricity supply in Canada: – Minimum 12 dBi gain , maximum beamwidth of 30o

– Appropriate for high capacity systems operating under LOS– What about for relatively low capacity systems in NLOS condition?

• Directional antennas do not have 100% of expected performance in NLOS – Broadening the pattern, Gain reduction– Reduction in Average Area Spectral– Increase of Co-channel Interference– Reduction in Coverage

Solution: Revising SRSP 301.7 to allow using Omni antennas for critical applications in SG

• Impacts of Using Omni for P2MP deployments:– Co-channel Interference, Coverage, ASE– Increased second best server redundancy– Cost effective deployments and Maintenances


THEME 3, PROJECT 3.2

Throughput analysis of Narrow-band Power Line Communications in Advanced Distribution AutomationChon Wang Chao (MEng Student)Quang-Dung Ho (Research Associate)Tho Le-Ngoc (McGill University)

Overview of the project

NSMG-Net Project 3.2: Chon Wang Chao

Fig. 1 – Studied communications architecture of PLC for ADA

Contribution of the project

• Data rate estimation– Packet structure specified by IEC 61850 client-server

communications– Expected data requirements for advanced

distribution automation• Impact of communication channel competition

– Throughput variation – Bandwidth requirement– Improvement from using Clear to Send/ Request to

Send mechanism




Frequency Regulation by Aggregator-based Electric Vehicles Charging Control via Wireless CommunicationsChon Chon Wang Chao (MEng Student)Quang-Dung Ho (Research Associate)Tho Le-Ngoc (McGill University)

Overview of the Project


• Frequency regulation with the battery capacity of electric vehicles (EV) • Intelligence resides at the aggregators which are used to coordinate the responses of the EVs

Fig. 2 – the proposed control and communications architecture of FR with EV

Contribution of the project


• Index system for selecting EV to participate in FR– Map the EV private information (e.g. SOC,

departure time) to an index – Aim to reduce the privacy concerns

• Impact of communications on FR– Frequency regulation performance (e.g. stability)

under non-ideal communications– Communication delay – Packet Loss



EFFICIENT COMMUNICATION ARCHITECTURE FOR INTELLIGENT MICROGRIDSTho Le-Ngoc (McGill University)Quang-Dung Ho (Research Associate)Yue Gao (MEng Student)Gowdemy Rajalingham (MEng Student)

CollectorRouter

Proposed System Architecture

Fig. 1 – Neighbor Area Network

UTILITY

Endpoints1026

LTE

Wired Backhaulxxx

xxx xxx

xxx

Command Center

Performance Evaluation

NSMG-Net Project 3.2: Gowdemy Rajalingham

Fig. 2 – Simulation Scenario, sweep of cluster size

Objective• Determine capabilities and limitations of NAN with GPSR• Investigate NAN clusters performance with various system parameters

TABLE 1 – SIMULATION PARAMETERS

Channel Model Simple pathloss – pathloss exponent , and Lognormal shadowing – variance

MAC layer IEEE 802.11

Routing Protocol Greedy Perimeter Stateless Routing (GPSR)

Performance Metrics Packet Transmission Delay & Packet Delivery Ratio (PDR)

Traffic Per-node data rate -

Topology Clusters of size -

System Parameters Sweeps of • Variance , default value of [dB] • Per-node data rate , default value of • Clusters of size , default value of

Project 3.3 Distribution Automation Communications:

PARTIAL DISCHARGE IMPULSIVE NOISE IN ELECTRICITY SUBSTATIONS AND THE IMPACT ON 2.4 GHZ AND 915 MHZ ZIGBEE COMMUNICATIONS

① What is the problem for substation communication systems:

I. The ZigBee wireless platform is a cost-effective wireless sensor networking system that can be used to monitor substation components in electric substations.

II. Impulsive noise with a short duration and strong energy content caused by partial discharge of a dielectric breakdown can degrade the communication quality of ZigBee nodes.

② What are we doing for the above problem:

I. Modelling the sequence of PD impulsive noise.

II. Analysis of the impact of impulsive noise on ZigBee systems operated at 915 MHz and 2.4 GHz bands.

③ What is the contribution of our research:

I. Assessment of ZigBee operational bands that are more resistant to impulsive noise in electricity substations.

II. Possibility of a ZigBee sesnor network that can be utilized for the detection of partial discharge events.


Project 3.4Integrated Data Management and PortalsStudent: Moein Manbachi (Simon Fraser University)Supervisors:Dr. Hassan Farhangi (British Columbia Institute of Technology)Dr. Ali Palizban (British Columbia Institute of Technology)Dr. Siamak Arzanpour (Simon Fraser University)

*Ref. International Energy Agency (http://www.iea.org)

Canada Electric Power Generation, Consumption and T&D Losses

In 2010, Canada T&D Loss value: 65.661 Billion-kWh. Average Transmission & Distribution Losses: % 8.5388 About %40 of T&D Losses occurs in Distribution Network

Ref. http://www.electricenergyonline.com

Importance of Energy Conservation & Distribution Network Optimization

Volt/VAR Optimization(VVO)

Project 3.4: Real-time

Smart Grid Adaptive Volt/VAR

Optimization

1. How Smart Grid new

features can help VVO?

2. What is our proposed solution?

3. What are the key

benefits of our solution?

4. Centralized Control Vs.

Decentralized Control5. Where we

are now? How far we

can go?

6. What will be the next

generation of VVO?

7. Case Study Results

8. Future Plans & Targets

VVO Technique can be improved by new Smart Grid Technologies

More efficient solution with better results

student poster competition 4 minute ‘elevator pitches’

Documents

hybrid control slide

frequency control

droop based control

sensitivity of control

autonomous microgrid

proposed control structure

microgrid facilities

microgrid ahda