1

Research and Developmentof Machine Drives and Power

Conditioning and its Development for Electric

VehiclesFrom 1999 to 2009

Prof. Eric Cheng

Department of Electrical Engineering

2

Four RGC projects leads to Four RGC projects leads to Electric VehiclesElectric Vehicles

From 1999 to 2002Future Switched Reluctance Machine Drives and Associated Power

Conditioning (RGC: PolyU5085/98E)

From 2003 to 2005Development of the Future Power Conversion Techniques Using Adaptive Control and Integrated Magnetics (PolyU 5103/01E)

From 2004 to 2007Design and Modeling of An Integrated Fuel Cell and Energy Storage System to Enhance Power System Performance and Reliability(PolyU

5245/04E)

From 2007 to 2009Formulation 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 (RGC: PolyU5085/98E) (1999~2004)

Outcome• Proposition of four models of SRM drives• Investigation of effects of control and output parameters on power factor in SRM drives• Proposition of new method to design controller with good power factor• Development of schemes to improve power factor in SRM drives•Development a soft-switching power conditioning

4

Future Switched Reluctance Machine Drives and Associated

Power Conditioning (RGC: PolyU5085/98E) (1999~2004)

Published papers

•10 Journal papers

•11 Conference papers

5

The two-dimensional bicubic spline interpolation is used to describe the nonlinear magnetic characteristics in switched reluctance motors

Simulation of Switched Reluctance Motor Drives Using Two-dimensional Bicubic Spline

IEEE Transactions on Energy Conversion

Interpolation Calculation

Calculating p1 j and pnj ( j=1,..., M )

Calculating qk1 and qkm (k=1,..., N )

Calculating r11 , r1m , rn1 and rnm

Solving Equation (8) and Obtaining pkj (k=2..., N -1, j=1,..., M )

Solving Equation (9) and Obtainingqkj (k=1..., N , j=2,..., M-1 )

Solving Equation (10) and (11), Obtaining rkj(k=2..., N-1 , j=1 and j= M , and k=1,...,N, j =2,..., M-1 )

Calculating Matrix C

Calculating Matrix V -1 and V - t

Calculating Matrix A

Return

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Influences of Outputs and Control Parameters upon the Power Factor

Establish the comprehensive SRM drives design, and is valuable to designing the good controller with high power factor

Electrical Components and Systems

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An Algorithm for Solving Initial Value Problems of Mutual-Coupling

The non-linear modeling of multiphase switched reluctance motors can be used to simulate SRM more accurately.

Electrical Components and Systems

8

Trigonometry-Based Numerical Method and Self-Training Numerical to Compute Nonlinear

Magnetic Characteristics

Provide a valuable approach for performance torque prediction, design, simulation, sensorless drive and control of SRMs

IEEE Transactions on Magnetics

9

Improvement of Power Factor Drives through Optimizing the Switching

Angles

A novel control strategy to improve the power factor of switched reluctance motor drives is proposed and the two schemes to improve the power factor are developed.

Electrical Components and Systems

10

Correlation of Modeling Techniques and Power Factor

IEE Proceedings Electric Power Applications

Unified modeling on sensorless control and power factor improvement of switched reluctance machine drives

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Position Stepping Method 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.

IEEE Transactions on Energy Conversion

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DC-DC Power Conditioning•Switched-capacitor power conditioning

•A family of circuit topology

•Improve the current shaping of the switched-reluctance drive

IET Proceedings/Letter, IEEE Trans Ind. Elec, EPCS

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Development of the Future Power Conversion Techniques Using Adaptive Control and

Integrated Magnetics(RGC: PolyU5103/01E)

(2002~2004)Published papers

•7 Journal papers

•5 Conference papers

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Project Outcomes

• Developed a new analyzed method for integrated magnetics

• Developed the passivity control method for power converters

• Developed a new Quasi Current Mode Control for DC-DC power converter

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Integrated Magnetics

Boost-flyback converter

Integrated magnetics version of Forward converter 60

65

70

75

80

85

90

95

100

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Duty Ratio

Eff

icie

ncy

(%

)

Flyback

Forw ard

Iso-Boost

Iso-Cuk

Boost-Flyback

Integrated Forw ard

•Developed a number of integrated magnetic circuits

•Examine the efficiency performance vs energy processing

IEE Proceedings EPA

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Passivity control

Improvement of the output response using PBC

new method

Conventional

)(ˆ2

02

1000 dt

vdcLCvvcvI dd

•Developed an adaptive controller for the phase-shifted controller

•Based on a passivity control theory

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21cos

22

2

1

rrm

in CLIkv

V

IEE Proceedings EPA

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Two Axis Indirect Current Mode Control

+

-

ePI PSRC

VVdα

Vi22 yx F(Vi)

Δ V

k4

VP

AV

BV iBV

AiV

PV

Phasor diagram of the resonant circuit

Controlled PSRC with new structure

IEEE Trans Power E

•A novel indirect current mode control system with voltage compensation for the control of the phase shifted resonant converter•Regulating the quadrature components of the voltage applied to the resonant circuit

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Design and Modeling of An Integrated Fuel Cell and Energy Storage System to

Enhance Power System Performance and Reliability(PolyU 5245/04E)

(2004~2007)

Fuel cell vehicle

Outcomes

•Developed a mathematic model of both dynamic and state-state for fuel cell

•Fuel cell with magnetic energy storage

•New family of ZCS and ZVS power conditioning

Published papers

•2 Journal papers

•2 Conference papers

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Unified Mathematical Modelling of Steady-State and Dynamic Voltage-Current Characteristics for PEM

Fuel Cells

Developed a novel approach for optimization of operating points of fuel cells and design of power conditioning units, simulators, and system controllers.

Electrochimical Acta

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ZVS and ZCS buck-boost converter

Buck-boost

Zepic1. Work well with fuel cell2. Has applied to fuel cell vehicle3. Zero-current and zero-voltage

switching4. Family of circuits developed

(IET Power Electronics)

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Formulation of DC Energy Factor and Its Implication on Control Method for High Efficiency Power Electronics Conversion

System (PolyU 5136/06E)(2007~2009)

•Develop a new definition of the energy factor for DC-DC power conversion

•Developed the energy factor control method

•Improve efficiency of the converter through energy factor

Published papers

•2 Submitted Journal papers

•2 Conference papers

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Boundary condition analysis

vL1

vL2

iL1

iL2

iC1

iC2

Vin

-Vo

Vin

-Vo

Δ iL1iL1

Δ iL2

iL1

iL2

iL2

Δ iL2

vL1

vL2

iL1

iL2

iC1

iC2

Vin

-Vo

Vin

-Vo

Δ iL1iL1

Δ iL2

iL1

iL2

iL2

Δ iL2

vL1

vL2

iL1

iL2

iC1

iC2

Vin

-Vo

Vin

-Vo

Δ iL1iL1

Δ iL2

iL1

iL2

Δ iL2

vL1

vL2

iL1

iL2

iC1

iC2

Vin

-Vo

Vin

-Vo

Δ iL1

Δ iL2

Δ iL2

Δ iL1

ILo

-ILo

ILo

-ILo-Io

vL1

vL2

iL1

iL2

iC1

iC2

Vin

-Vo

Vin

-Vo

Δ iL1

Δ iL2

Δ iL2

Δ iL1

ILo

-ILo

ILo

-ILo-Io

DK 12 DK 12 21

12

D)(K

DK

2)1( DK 2)1( DK

DTS

TS

DTS

TS

DTS

TS

DTS

TS TS

TSδDTS

CCM DCM Mode 1 DCM Mode 2

(a) (b) (c) (d) (e)

•Developed the boundary condition for the Switched-mode converter

•Developed the formulation of energy factor under boundary condition

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Generalized analysis for energy storage

iinqΔ iL

iL

Vin

-Iin

-Iin

qin

DT

T

Non-active instantaneous power

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90

0.2

0.4

0.6

0.8

1

1.2

1.4

D

FE

Zeta

Cuk and Sepic

Input energy factors under CCM Energy Factor Under CCM

•Developed the generalized energy in storage device

•Developed the characteristics with duty ratio

•Provide the techniques to select power converter for various power applications

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The Development of Electric Vehicles

• Through the GRC projects, it leads to the following technological developments:– SR motor design– SR motor drive– High frequency magnetic design– Family of switched mode high power converters– Soft-switching power condition– Fuel cell power conditioning– Energy storage device– Optimal Performance of converters

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Motor and DrivesElectric Vehicle Development• Integration of motor and wheel

• Reduce all the mechanical interfacing

• In-wheel motor vehicle

SRM driver SRM Finite element model

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Power Converter Driver to LED and HID Lighting

LED Headlight

HID lamp ballastLED lamp and driver

LED Tail light

•Developed the LED driver

•Developed the HID lamp driver

•Installed on commercial vehicle

LED and HID headlight

HID lamp

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Charging system

CLP Power charging system in Hong Kong High power fast charger

Simple plug-in EVBattery Management System

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In-wheel motor for 4-wheel drive

•1st Electric Vehicle using in-wheel reluctance drives

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DC-DC Power Design for Electric Vehicle

1st commercial vehicle in HK Conversion to EV

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SummarySummary• Research and development of Power Electronics

technology in Switched Reluctance Machine drives, DC-DC Power Conversion, Magnetics and Energy Storage Advanced design and control techniques have been developed.

• Arising from RGF, 20 journal papers and numerous conference papers have been published.

• Applications to electric vehicles are most prominent• Extend the research to commercial products and

collaborate with a number of companies CLP, Tenpao, Shun Hing Power, Fok Yin Tung, Hopewell,…

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Thank You