webinar | hil testing of electric transportation

HIL Testing of Electric Transportation

May 26, 2016

Your Hosts

DemoSébastien CenseFPGA Application SpecialistOPAL-RT TECHNOLOGIES

Presenter François BerthelotEngineerOPAL-RT TECHNOLOGIES

Keynote SpeakerDr. Hao HuangTechnology Chief – Electrical PowerGE Aviation

Presentation Outline

1 2 3 4 5

Introduction & Challenges

Case Studies

Live Demo

GE AviationDr. Huang

Conclusion

Introduction to electric drives

Electric drives are nowadays found in a wide range of transportationapplications.

In the automotive industry1: Hybrid vehicles Plug-in hybrid vehicles Hydrogen fuel cell vehicles Battery electric vehicles1

In other industries: Aircraft Off-highway vehicles (OHV) Electric locomotives Integrated/full electric marine propulsion systems (IEP/FEP)

For engineers involved in drive simulation and in hardware-in-the-loop testing of electronic control units (ECU), the variety of challenges, technologies and solutions can be daunting.

1 – According to the Society of Automotive Engineers (SAE) International.

Introduction to electric drives

OPAL-RT’s vision on hardware-in-the-loop electric drive applications:

Electric Motors Power ConvertersTypes

Permanent Magnet Synchronous Motor (PMSM)

Switched Reluctance Motor (SRM)

Brushless DC Motor (BLDC)

Induction Motor (IM)- DFIG, DFIM, squirrel-cage

Etc.

Types

DC-DC Converters, Buck / Boost

AC-DC Rectifiers

DC-AC Inverters

Neutral-Point Clamped Converters

Cycloconverters, Matrix Converters

Modular Multi-Level Converters

Etc.

ECU under test

Electric drives, inside transportation systems, do not comealone. They are part of complex ecosystems which includesurrounding physical environments with communicationlayers and dynamics control.

Testing electric drives requires complete test coverage ofpossible failure cases. A real-time HIL simulator that canperform such scenarios must support simple and efficientscripting.

HIL testing of electric drives also aims at minimizingdynamometer testing. Having the freedom to rely on a veryaccurate real-time simulation, rich in harmonics, providingcurrent saturations and real torque phenomena is important.Power amplifiers can also be used to go beyond controllertesting.

CAN bus, Modbus,ARINC, …

FaultsProtocols

Scripts

Dynamics

System&

Environment

Challenge 1: High-Fidelity Motor Simulation

Historically, real-time simulation of electric motors has been achievedby computing equations on processors (CPUs).

With such technology, timing constraints to achieve accuratesimulation of motors and associated drives are non-negligible. Withlimited time steps down to 20 us to 50 us on CPU, model complexityhad to be kept simple in order to run in real-time with no overruns.

In order to get acceptable results, engineers had to fall back ongeneric motor models, average models, limit the rotational speed orlimit the switching frequency among others.

This did not deliver the fidelity required to represent all harmonics,saturations and ultimately to couple simulated motors with fastsimulated power converters and surrounding systems.

Nowadays, real-time electric motor simulation is executed on FPGA, where time steps achieved are typically below 1 microsecond. By being application-specific, FPGAs can be fully dedicated to the task.


… But programming detailed electric motors on FPGA is challenging and requires specialized tools. Due to this, generic or pre-built motor models are still common.

Timing constraints are reduced Simulation accuracy is increased Reach sufficient levels of harmonics and detailed saturation curves Reach extended rotational speeds and switching frequencies in simulation

Test coverage is expanded Reliability and confidence are stronger


To circumvent such limitations, FPGA-based real-time simulationof motor models is now coupled with finite element analysis(FEA) tools. High-fidelity inductance tables are generated fromthose tools and are directly imported in the electric motorsimulation on FPGA.

Takes in account non-linearity and allows real-time simulationmotor inductance variations at high current

Fidelity related to detailed electric motor modeling is increased

Motor designers and HIL specialists work with a common tool Efficiency related to electric motor design and

testing is enhanced

Another key component of electric drives is fast powerelectronics components.

High-frequency switching is used nowadays to reduce the filter size, the size of other components in the converter, the harmonics of the output signals, as well as to increase the control bandwidth among others.

Using an FPGA-based technology for real-time simulation is therefore preferred.

Similarly to the electric motors, programming power converters on FPGA is challenging and again requires specialized tools and skills.

Challenge 2: Fast power electronics components in HIL

TypicalApplication

TypicalFrequency

Typical Time Step

Temperature control 1 Hz 1 second

Human Vision (video) 24 Hz 42 ms

Aircraft Model (simulation) 200 Hz 5 ms

Robotics 1000 Hz 1 ms

Fuel Engine Control 10 000 Hz 100 us

Power Grid Simulation (AC systems) 20 000 Hz 50 us

Low frequency Power Electronics 100 000 Hz 10 us

Finite Element PMSM Motors 2 500 000 Hz 0.4 us

High Frequency Power Electronics 5 000 000 Hz 0.2 us

eHS (electric Hardware Solver) enables to simulate fast power converter circuits with time steps ranging from 150 nanoseconds to 2 microseconds:

No FPGA expertise or programming needed Direct interface with SimPowerSystems, PSIM, PLECS and Multisim Test different scenarios without rebuilding code

…But, this could be considered a power electronics HIL environment « only », while users must couple it with multi-rate components of the surrounding system such as motors, power systems, transmissions, braking systems, etc. HIL tools integration then becomes vital.


HIL architecture using CPU and FPGA allows users to get the best from both worlds:

Dedicated FPGA for electric motors, power converters, fault injection, …


Flexible CPU for simulating surrounding systems, dynamics, control algorithms, communication networks, …

CAN bus, Modbus,ARINC, …


21 3 4 5

Case Studies


Live Demo


Conclusion

Case Study: Hybrid Driveline Design & Control

SIMULATION NEEDS:

An electric drive with:

Two Permanent Magnet Synchronous Motors

High-Impedance Capable Inverter

Boost Converter

PWM Frequencies: 2 to 20 kHz

Dead Time: 2 to 20 μs Production Controller

TESTS CONDUCTED:

Phase over-current detection

Boost converter action via speed increase

VVC boost via torque command

Case Study: Conservation of dynamometer time

SIMULATION NEEDS:

Software development phase for ECU includes:

Engine simulation

Electric motor model simulation : Allows the user to check the motor algorithms and drivers

Communication network simulation: Multiple CAN and FlexRay channels

Fault testing: Fault, diagnostic, and error message responses

As presented during the OPAL-RT RT13 Conference (June 2013)

BENEFITS:

Because the dynamometers are expensive, many organizations multiplex the access to the dynamometer across several programs Objective = Reduce dyno time and optimize schedule to lessen the chances of incurring “lost opportunity cost”

With real-time simulation, the developers can approach the dynamometer with a 90% confidence that the system will perform as expected

Allows the engineers to focus on the performance of the system and not on the process of making the system work Wider test coverage

Increase customer satisfaction, while cutting cost, and increasing reliability

Case Study: Rapid Control Prototyping of Powertrains

SIMULATION NEEDS:

Simulink integration

PWM and A/D Synchronization

Resolver Input (position)

Data logging and HCI

OBJECTIVES & ACHIEVEMENTS:

Design new algorithms and control laws

Test their efficiency on a prototype

Demonstrated new electric automobile concepts

Decreased development time


321 4 5

Live Demo

Case Studies



Conclusion

OP8665 DSP Board

eHS Solution – Chassis Support

Host Computer(Console)

Design Power Electronics Circuit

Real-TimeSimulator

FPGA

Execute the simulation

Physical controller

Interface the controller

eHS Solution – Unique Workflow

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1.51 kHz PWM (UA)

Logic

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Offlineresults

eHS Matrix Generation

Real Time Simulation

Onlineresults

eHS workflow

Offline simulation

+-

Model Validation

eHS Solution – Unique Workflow


42 31 5


Case Studies

Live DemoIntroduction& Challenges

Conclusion


521 43

Conclusion

Case Studies



Live Demo

Electric drive real-time simulation evolves in complex ecosystems

- Dedicated software tools running on CPU and FPGA-based technologies that can be

coupled together are required, such as eMEGAsim and eHS

Complete test coverage is needed

- Wide range of fault scenarios possible with accurate models even in limit conditions

Minimize dynamometer testing

- Replaced by high-fidelity real-time simulation and Power-HIL

In Conclusion

For more information

Visit our electric motor and power electronics webpage:

http://www.opal-rt.com/electric-motor-and-power-electronics

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