Reduced Structure Inverter Fed Electric Motor Drives: an Attempt to Improve the Cost-effectiveness, the Compactness and the Reliability of Electric and

Reduced Structure Inverter Fed Reduced Structure Inverter Fed Electric Motor Drives: an Attempt Electric Motor Drives: an Attempt

toto Improve the Cost-effectiveness, Improve the Cost-effectiveness, the Compactness and the Reliability of the Compactness and the Reliability of ElectricElectric andand Hybrid Propulsion SystemsHybrid Propulsion Systems

Research Unit on Renewable Energies & Electric Vehicles

University of Sfax

Sfax Engineering School

Tunisia

Ahmed Masmoudi

Life Cycle Protection: Life Cycle Protection: a Universal Commitmenta Universal Commitment

Automotive Industry: Automotive Industry: FlashbackFlashback

Till the 60th, automotive manufacturersdidn’t worry about the cost of fuel. They have never heard of air pollution, and theyhave never thought about life cycle. Ease of operation with reduced maintenance costs meant everything back then.

Air Pollution: the MajorAir Pollution: the MajorDrawback of ICEDrawback of ICE

ICEICE

airairpollutiopollutio

nn

Automotive Industry: Automotive Industry: New TrendsNew Trends

Times have changed. In recent years, clean air mandates are driving the market to embrace new propulsion systems in order to substitute or to assist the ICE,resulting in electric and hybrid vehicles.

Series Hybrid PowertainSeries Hybrid Powertain

Parallel Hybrid PowertrainParallel Hybrid Powertrain

Series/Series/Parallel Hybrid Parallel Hybrid PowertrainPowertrain

Electric Machine DesignElectric Machine Design::New TrendsNew Trends

New approach which considers that the best machine design is the one providingthe optimum match between the machine and the associated converter leading to the so-called converter-fed machines.

Electric Machine DrivesElectric Machine Drives: : Conventional SSTPIConventional SSTPI

ElectricMotor

Vc

S3S2S1

S4 S5 S6

AB

C

Reduced Structure Inverters:Reduced Structure Inverters:What is gained?What is gained?

Lower number of the power switches and of the Lower number of the power switches and of the associated control boards with respect to the associated control boards with respect to the conventional SSTPIconventional SSTPI

Improvement of the cost-effectivenessImprovement of the cost-effectiveness

Decrease of the occupied volume Decrease of the occupied volume

Enhanced reliability thanks to the reduction of Enhanced reliability thanks to the reduction of the luck of failuresthe luck of failures

OutlineOutline

Study statement

FSTPI fed electric machine drives

FSTPI fed BDCM drives

FSTPI fed IM drives

TSTPI fed electric machine drives

TSTPI fed BDCM drives

TSTPI fed IM drives

Conclusion and Outlook

Four-switch Three-phase Four-switch Three-phase Inverter Fed Electric Inverter Fed Electric

Machine DrivesMachine Drives

Connections of the FSTPIConnections of the FSTPI

FSTPI Fed Brushless DCFSTPI Fed Brushless DCMotor DrivesMotor Drives

FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Principle of Operation Principle of Operation

FSTPI Fed BDCM: FSTPI Fed BDCM: Principle of Operation Principle of Operation





FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Linear Speed Control Linear Speed Control

FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Start-upStart-up

SSTPI Fed BDCM Drive: SSTPI Fed BDCM Drive: Start-upStart-up

FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Start-upStart-up

SSTPI Fed BDCM Drive: SSTPI Fed BDCM Drive: Start-upStart-up

FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Steady-state OperationSteady-state Operation

SSTPI Fed BDCM Drive: SSTPI Fed BDCM Drive: Steady-state OperationSteady-state Operation

FSTPI Fed BDCM Drive: FSTPI Fed BDCM Drive: Fuzzy Speed Control Fuzzy Speed Control

FSTPI Fed InductionFSTPI Fed InductionMotor DrivesMotor Drives

FSTPI Fed IM Drive:FSTPI Fed IM Drive:Direct Torque Control SchemeDirect Torque Control Scheme

Φs

θs1

3

65

4

2

Vα

Vβ

V2

V1

V3

V4

V5 V6

V0

V7

DTC of FSTPI Fed IM Drive:DTC of FSTPI Fed IM Drive:Vector Selection Table Vector Selection Table

V4

V3

V2

V1

V7

V0

V7

V0

V7

V0

V2

V1

V6

V5

V4

V3

V5

V4

V3

V2

V1

V6

V0

V7

V0

V7

V0

V7

V1

V6

V5

V4

V3

V2

S6

S5

S4

S3

S2

S1

-10+1-10+1

-1+1

cT

c

V5

V6

3

2

1

Vα

Vβ4

V1

V3V4

V2

V2

V4V8

V6

V3V1

V5V7

DTC of FSTPI Fed IM Drive:DTC of FSTPI Fed IM Drive:Vector Selection TableVector Selection Table

7

Vαs

Vβs

V1

V2

V4V8

V6

V7

V1

V3

V5

1019

1

2

3 45

6

7

8

9

11

12

131415

16

17

18

20

3

2

4

1

Vαs

Vβs

V1

V2

V4V8

V6

6

8

V7

V1

V3

5

V5

DTC of FSTPI Fed IM Drive:DTC of FSTPI Fed IM Drive:Vector Selection TableVector Selection Table

0 0.5 1 1.5 20

20

40

60

80

100

120[rad/s]

0 0.5 1 1.5 20

20

40

60

80

100

120

*m m [rad/s]*

m m

Time [sec] Time [sec]

*m *

mm m

SSTPISSTPI FSTPIFSTPI

DTC of a FSTPI Fed IM Drive:DTC of a FSTPI Fed IM Drive:Transient Behavior During Start-upTransient Behavior During Start-up



0 0.5 1 1.5 2-10

0

10

20

30

40

50

60

Time [sec]0 0.5 1 1.5 2

-10

0

10

20

30

40

50

60

Time [sec]

[Nm]Tem lT[Nm]Tem lT

lT lT



0 0.5 1 1.5 2-120

80

-40

0

40

80

120ias [A]

Time [sec]0 0.5 1 1.5 2

-120

80

-40

0

40

80

120ias [A]

Time [sec]



-0,8 -0,4 0 0.4 0.8-0.8

-0.4

0

0.4

0.8

αs[Wb]

βs[Wb]

-0,8 -0,4 0 0.4 0.8-0.8

-0.4

0

0.4

0.8

αs[Wb]

βs[Wb]


DTC of a FSTPI Fed IM Drive:DTC of a FSTPI Fed IM Drive:Steady-state FeaturesSteady-state Features

1.96 1.975 1.990

1

2

3

4

5

6

7

Time [sec]

Sk

1.96 1.975 1.990

2

4

6

8

10

12

14

16

18

20

22

Time [sec]

Sk



1.96 1.975 1.99-30

-20

-10

0

10

20

30

Time [sec]1.96 1.975 1.99

-30

-20

-10

0

10

20

30

Time [sec]

ibs ics ias ias ibs ics



5 10 15 20 25 30 35 40 45 500

5

10

15

20

25Amplitude [A]

Harmonic rank

5 10 15 20 25 30 35 40 45 500

5

10

15

20

25Amplitude [A]

Harmonic rank

Three-switch Three-phase Three-switch Three-phase Inverter Fed Electric Inverter Fed Electric

Machine DrivesMachine Drives

Connections of the TSTPIConnections of the TSTPI

S1

S2

S3

D3

D2

D1

i1

i2

i3

TSTPI

i a

i b

i c

electricmotor

TSTPI Fed Brushless DCTSTPI Fed Brushless DCMotor DrivesMotor Drives

TSTPI Fed BDCM Drive: TSTPI Fed BDCM Drive: Principle of operationPrinciple of operation

Principle of OperationPrinciple of Operation

TSTPI Fed BDCM Drive: TSTPI Fed BDCM Drive: Linear Speed ControlLinear Speed Control

Time (s)0 0.4 0.7 1 1.3

0

2

4

6

8

10

12

14

16

18

(N.m)

Tem

Tl

0 0.4 0.7 1 1.30

2

4

6

8

10

12

14

16

18

Time (s)

(N.m)

Tem

T l

1.21 1.211 1.212 1.213 1.214 1.215 1.216 1.217 1.218 1.2194

4.5

5

5.5

6

Time (s)

(N.m) Tem Tl

Electromagnetic and Load TorquesElectromagnetic and Load Torques

SSTPISSTPITSTPITSTPI

TSTPI Fed BDCM Drive: TSTPI Fed BDCM Drive: Start-upStart-up

0 0.4 0.7 1 1.3-100

-80

-60

-40

-20

0

20

40

60

80

100

Time (s)

(A)

i a

1.21 1.215 1.22 1.225 1.23-40

-30

-20

-10

0

10

20

30

40

ia (A)

Time (s)

TSTPI Fed BDCM Drive: TSTPI Fed BDCM Drive: Start-upStart-up

Phase CurrentPhase Current

EeqRΩ

Cdl

Rtc

Zw

Zi

Modified Modified RandlesRandles Equivalent Circuit Equivalent Circuitof an Ni-mH Batteryof an Ni-mH Battery

)(1

)( pZsCR

RRsZi w

dltc

tc

Ω

C

R1

C

R2

C

Rn

Accounting for the Accounting for the Equivalent Equivalent Circuit of the Battery PackCircuit of the Battery Pack

-1000 0.4 0.7 1 1.3

-80

-60

-40

-20

0

20

40

60

80

100

Time (s)

ia (A)

Ideal battery pack Equivalent circuit of thebattery pack accounted for

-1000 0.4 0.7 1 1.3

-80

-60

-40

-20

0

20

40

60

80

100

Time (s)

ia (A)


Ideal battery pack Equivalent circuit of the battery pack


1.21 1.215 1.22 1.225 1.23-40

-30

-20

-10

0

10

20

30

40

ia (A)

Time (s)1.21 1.215 1.22 1.225 1.23

-40

-30

-20

-10

0

10

20

30

40

ia (A)

Time (s)

TSTPI Fed Induction TSTPI Fed Induction Motor DrivesMotor Drives

i1

Inductionmotor

S2

i2

i3

S1S3

*+-m

m

Speed controller

Tem*

Tem

K1 K2 K3

Bang-bang current controllers+

-

+ -

-+

Park transform

2 3Currents (a-b-c)

Currents (1-2-3)

i2

i3

i1

*

*

*

ib

ic

ia

*

**

i2

i1

i3

*ids

+- Torque

controller

iqs*

++ p

ωs

θs

Currents (a-b-c)

Currents (1-2-3)Park transform

3 2

ib

ic

iaids

iqs

ФrRotor flux controller

Фr*

ωr

TSTPI Fed IM Drive:TSTPI Fed IM Drive: RFOC Implementation Scheme RFOC Implementation Scheme

SSTPI TSTPI

20 0.4 0.8 1.2 1.60

100

200

300

400

500

600

Time (s)

(rpm) *m

m

0 0.4 0.8 1.2 1.6 20

100

200

300

400

500

600

Time (s)

(rpm) *m

m

TSTPI Fed IM Drive TSTPI Fed IM Drive Performance Under RFOCPerformance Under RFOC

Reference and motor speeds

SSTPI

0 0.4 0.8 1.2 1.6 2-10

0

10

20

30

40

50

Time (s)

(N.m)

Tem

Tl

TSTPI

0 0.4 0.8 1.2 1.6 2-10

0

10

20

30

40

50

Time (s)

(N.m) TemTl


Electromagnetic and load torque

The ‘’a’’ phase current

SSTPI TSTPI

-40

-30

-20

-10

0 0.4 0.8 1.2 1.6 2

0

10

20

30

40

Time (s)

ia (A)

0 0.4 0.8 1.2 1.6 2-40

-30

-20

-10

0

10

20

30

40

Time (s)

ia (A)

Steady-state phase current profiles

1.8 1.81 1.82 1.83 1.84 1.85-20

-15

-10

-5

0

5

10

15

20

Time (s)

(A) ia ib ic

1.8 1.81 1.82 1.83 1.84 1.85-20

-15

-10

-5

0

5

10

15

20

Time (s)

(A) ia ib ic


TSTPI Fed IM Drive:TSTPI Fed IM Drive: Sensorless RFOC Strategy Sensorless RFOC Strategy

Sensorless RFOC strategy Conventional RFOC strategy

Reference and motor speeds

20 0.4 0.8 1.2 1.60

100

200

300

400

500

600

Time (s)

(rpm) *m

m

0 0.4 0.8 1.2 1.6 20

100

200

300

400

500

600

Time (s)

(rpm) *m

m

TSTPI Fed IM Drive TSTPI Fed IM Drive Sensorless RFOCSensorless RFOC

Speed estimation error

0 0.4 0.8 1.2 1.6 2-0.04

-0.02

0

0.02

0.04

Time (s)

m- est

TSTPI Fed IM Drive TSTPI Fed IM Drive Sensorless RFOCSensorless RFOC

ConclusionConclusion

Improvement of the Improvement of the cost-effectivenesscost-effectiveness, the , the compactnesscompactness and the and the reliabilityreliability of electric and hybrid propulsion systems of electric and hybrid propulsion systems gained by the integration of reduced structure invertersgained by the integration of reduced structure inverters

Feasibility thanks to the availability of the Feasibility thanks to the availability of the battery packbattery pack

Both FSTPI and TSTPI associated with machines fed by:Both FSTPI and TSTPI associated with machines fed by: rectangular currents (BDCM) rectangular currents (BDCM) sinusoidal currents (IM)sinusoidal currents (IM)

Almost Almost the same performancethe same performance as those achieved with as those achieved with conventional SSTPIconventional SSTPI

Limitation of the speed rangeLimitation of the speed range due to the reduction of the due to the reduction of the average DC voltage supplyaverage DC voltage supply

OutlookOutlook

The development of The development of experimentalexperimental test benchestest benches for the sake of the for the sake of the validation of the predicted validation of the predicted performanceperformance

Rethought the capabilities of reduced structure Rethought the capabilities of reduced structure inverters from a inverters from a troubleshootingtroubleshooting point of viewpoint of view in in an attempt to solve temporarilyan attempt to solve temporarily SSTPI failures SSTPI failures

Solve the problem of Solve the problem of speed limitationspeed limitation through a through a reconsideration of the machine designreconsideration of the machine design in order in order to to extend the flux weakening range extend the flux weakening range

AcknowledgmentAcknowledgment

These works were partly supported byThese works were partly supported by

Allison Transmission Division of GMsAllison Transmission Division of GMs

(ATDGM, Indiana, USA). (ATDGM, Indiana, USA).

Many thanks should be addressed to Dr. Many thanks should be addressed to Dr.

Ahmed El-Antably, staff project engineer Ahmed El-Antably, staff project engineer

with ATDGM, for the valuable discussions.with ATDGM, for the valuable discussions.

AcknowledgmentAcknowledgment

Full recognition needs to be given here Full recognition needs to be given here

to Prof. Abdessattar Guermazi, to Asso. Prof.to Prof. Abdessattar Guermazi, to Asso. Prof.

Asma Ben Rhouma and Bassem EL Badsi, andAsma Ben Rhouma and Bassem EL Badsi, and

to Ass. Tec. Mariem Sahbi and Mourad Masmoudi.to Ass. Tec. Mariem Sahbi and Mourad Masmoudi.

Reduced Structure Inverter Fed Reduced Structure Inverter Fed Electric Motor Drives: an Attempt Electric Motor Drives: an Attempt

to Improve the Cost-effectiveness, to Improve the Cost-effectiveness, the Compactness and the Reliability of the Compactness and the Reliability of

Electric and Hybrid Propulsion SystemsElectric and Hybrid Propulsion Systems

Research Unit on Renewable Energies & Electric Vehicles

University of Sfax

Sfax Engineering School

Tunisia

Ahmed Masmoudi

4 Switch 3 Phase Inverter 4 Switch 3 Phase Inverter Fed Brushless DC MotorFed Brushless DC Motor

Transverse Flux Transverse Flux Permanent Magnet Permanent Magnet

MachinesMachines

Connections of the TSTPIConnections of the TSTPI

AchievementsAchievements 1 patent financed by Allison Transmission Division of GM (IN, USA)1 patent financed by Allison Transmission Division of GM (IN, USA)

6 papers in the Int. J. for Computation & Mathematics in Electrical 6 papers in the Int. J. for Computation & Mathematics in Electrical and Electronic Engineering (COMPEL)and Electronic Engineering (COMPEL)

2 keynote speeches in the Int. Workshop on Electric and Hybrid 2 keynote speeches in the Int. Workshop on Electric and Hybrid Automotive Technologies (WAT’07, Sfax, Tunisia)Automotive Technologies (WAT’07, Sfax, Tunisia)

8 communications in conferences:8 communications in conferences: 1 in EPE’03 (Toulouse, France)1 in EPE’03 (Toulouse, France) 3 in SSD’05 and SSD’07 (Sousse and Hammamet, Tunisia) 3 in SSD’05 and SSD’07 (Sousse and Hammamet, Tunisia) 4 in EVER’07 (Monte-Carlo, Monaco)4 in EVER’07 (Monte-Carlo, Monaco)

DiplomasDiplomas 1 HDR supported 1 HDR supported 3 PhD in progress3 PhD in progress 4 Masters (3 supported, 1 in progress)4 Masters (3 supported, 1 in progress)

TSTPI-BDCM drive test bench under development TSTPI-BDCM drive test bench under development

Documents

Reduced Structure Inverter Fed Electric Motor Drives: an Attempt to Improve the Cost-effectiveness, the Compactness and the Reliability of Electric and