1. Department of Electrical Engineering
Research and Development of Machine Drives and Power Conditioning Strategy and its Development for Electric Vehicles
From 1999 to 2009
Prof. Eric Cheng
Department of Electrical Engineering

2. Four RGC projects leading to Current Accomplishments on Electric Vehicles
From 1999 to 2002
Future Switched Reluctance Machine Drives and Associated Power Conditioning (PolyU5085/98E)
From 2003 to 2005
Development of the Future Power Conversion Techniques Using Adaptive Control and Integrated Magnetics (PolyU 5103/01E)
From 2004 to 2007
Design and Modeling of An Integrated Fuel Cell and Energy Storage System to Enhance Power System Performance and Reliability (PolyU 5245/04E)
From 2007 to 2009
Formulation of DC Energy Factor and Its Implication on Control Method for High Efficiency Power Electronics Conversion System (PolyU 5136/06E)

3. Future Switched Reluctance Machine Drives and Associated Power Conditioning Strategy RGC: PolyU5085/98E) (1999~2004)
Outcome
Proposition of four models of SRM drives
Investigation of the effects of control & output parameters upon power factor in SRM drives
Proposition of new method to design controllers with good power factor
Development of schemes to improve the power factor in SRM drives
Development of a soft-switching power conditioning strategy
a) the interpolation model based on bicubic spline, b) the analytical model of SRM based on the two-dimensional lest squares, c) the hybrid model based on bicubic spline and bilinear spline, and d) the multi-phase model with mutual coupling
b) The control parameters include the turn-on angle, turn-off angle, freewheeling angle, the duty cycle and chopping modes under voltage PWM control, the reference current, hysteresis band and chopping modes under current hysteresis control, input voltage, dc link capacitance.
c) good power factor are that the proper switching angles are determined,
d) One of which is based on the real-time optimization of the switching angles. The other is based on the off-line Hooke-Jeeve pattern optimization of the switching angles.

4. Future Switched Reluctance Machine Drives and Associated Power Conditioning Strategy (RGC: PolyU5085/98E) (1999~2004)
Published papers
10 Journal papers
11 Conference papers

5. Simulation of Switched Reluctance Motor Drives Using Two-dimensional Bicubic Spline
IEEE Transactions on Energy Conversion
A two-dimensional bicubic spline interpolation is used to describe the nonlinear magnetic characteristics in switched reluctance motors

6. Influences of Outputs and Control Parameters upon the Power Factor of SRM
Electrical Components and Systems
Establish a comprehensive SRM drives design to realize good controllers with high power factor

7. An Algorithm for Solving Initial Value Problems of Mutual-Coupling
Electrical Components and Systems
The non-linear modeling of multiphase switched reluctance motors has been developed to simulate SRM accurately.

8. Trigonometry-Based Numerical Method and Self-Training Numerical to Compute Nonlinear Magnetic Characteristics
IEEE Transactions on Magnetics
Provide a valuable approach for design, simulation, sensorless drive and control as well as torque prediction of SRMs

9. Improvement of Power Factor Drives through Optimizing the Switching Angles
Electrical Components and Systems
Novel control strategy to improve the power factor of SRM drives is proposed and two schemes to improve its power factor are developed.

10. Correlation of Modeling Techniques and Power Factor
IEE Proceedings Electric Power Applications
Unified modeling on sensorless control and power factor improve-ment of switched reluctance machine drives has been proposed

11. Position Stepping Method
IEEE Transactions on Energy Conversion
Based on 2-D bicubic spline and 2-D bilinear spline, the proposed position stepping method is used to predict the performances of switched reluctance motor (SRM) drives.

12. AC Resistance of Multistranded Conductor Inductors with Multilayers
IEEE Transactions on Magnetics
Generalized solution for AC resistance
Suitable for multi-layers and multi-strands

13. DC-DC Power Conditioning
IET Proceedings/Letter, IEEE Trans Ind. Elec, EPCS
Switched-capacitor power conditioning
A family of circuit topologies
Improve the current shaping of the switched-reluctance drive

14. Development of Future Power Conversion Techniques Using Adaptive Control and Integrated Magnetics (RGC: PolyU5103/01E) (2002~2004)
Published papers
7 Journal papers
5 Conference papers

15. Project Outcomes
Developed a new analytical method for integrated magnetics
Developed the passivity control method for power converters
Developed a new Quasi Current Mode Control strategy for DC-DC power converters

16. Integrated magnetics version of Forward converter
IEE Proceedings EPA
Integrated magnetics version of Forward converter
Developed a number of integrated magnetic circuits
Examine the efficiency performance vs energy processing
Boost-flyback converter

17. Passivity control
Developed an adaptive controller for phase-shifted control based on a passivity control theory
IEE Proceedings EPA
Conventional
new method
Improvement of output response using PBC

18. Two Axis Indirect Current Mode Control
IEEE Trans Power E
A novel indirect current mode control system with voltage compensation for the control of phase shifted resonant converters
Regulating the quadrature components of the voltage applied to the resonant circuit
Controlled PSRC with new structure
Phasor diagram of the resonant circuit

19. Design and Modeling of An Integrated Fuel Cell and Energy Storage System to Enhance Power System Performance and Reliability in Energy Storage Systems (PolyU 5245/04E) (2004~2007)
Outcomes
Developed a mathematic model of both dynamic and state-state for fuel cell
Study fuel cell with magnetic energy storage
Propose a new family of ZCS and ZVS power conditioners
Published papers
2 Journal papers
2 Conference papers
Fuel cell vehicle

20. Unified Mathematical Modelling of Steady-State and Dynamic Voltage-Current Characteristics for PEM Fuel Cells
Electrochemical Acta
Developed a novel approach for optimization of the operating points of fuel cells and design of power conditioning units, simulators, and system controllers.

21. ZVS and ZCS Converters Work well with fuel cells
IET Power Electronics
Work well with fuel cells
Has been applied to fuel cell vehicle
Zero-current and zero-voltage switching are realized
Family of circuits developed
Zepic
Buck-boost

22. Formulation of DC Energy Factor and Its Implication on Control Method for High Efficiency Power Electronics Conversion System (PolyU 5136/06E) (2007~2009 on-going)
Developed the concept and a new definition of the energy factor for DC-DC power conversion
Developed an energy factor control method
Improved the efficiency of converters via energy factor
Published papers
2 Submitted Journal papers
2 Conference papers

23. Boundary condition analysis
Developed the boundary condition for Switched-mode converter
Developed the formulation of energy factor under boundary condition

24. Generalized analysis for energy storage
Developed a generalized energy approach in storage devices
Developed a systematic study on the characteristics of storage devices with duty ratio
Provide techniques to select the optimal power converter for various power applications
Non-active instantaneous power
Energy Factor Under CCM
Input energy factors under CCM

25. The Development of Electric Vehicles
Through the RGC projects, the team has accomplished the following technological developments:
SR motor design
SR motor drive
High frequency magnetic design
Family of switched mode high power converters
Soft-switching power conditioner
Fuel cell power conditioner
Energy storage device
Optimal Performance of converters

26. Motor and Drives Electric Vehicle Development
Integration of motor and wheel
Minimize mechanical interfacing
Realize in-wheel motor vehicle
SRM driver
SRM Finite element model

27. Power Converter Driver to LED and HID Lightings
Developed LED driver
Developed HID lamp driver
Installed on commercial vehicle
HID lamp
LED Headlight
LED and HID headlight
LED lamp and driver
HID lamp ballast
LED Tail light

28. Charging system High power fast charger
CLP Power charging system in Hong Kong
Battery Management System
Simple plug-in EV

29. In-wheel motor for 4-wheel drive
1st Electric Vehicle using in-wheel reluctance drives

30. DC-DC Power Design for Electric Vehicle
1st commercial vehicle in HK
Conversion to EV

31. Summary
Research and development of Power Electronics technology in Switched Reluctance Machine drives, DC-DC Power Conversion, Magnetics and Energy Storage with advanced design and control techniques have been developed.
Arising from RGC Projects, 20 journal papers and numerous conference papers have been published.
Applications to electric vehicles are most prominent
Extension of the research to commercial products and collaborates with a number of companies including
CLP, Tenpao, Shun Hing Power, Fok Yin Tung Foundation, Hopewell,…

32. Thank You