Power electronics - University of Southern Californiaalevi.usc.edu/Html/publications/PRW Cuk_TESLAco.pdf · Power electronics Slobodan Cuk came to Caltech in 1974 and obtained his

Power electronics Slobodan Cuk came to Caltech in 1974 and obtained his PhD degree in Power Electronics in 1976. From 1977 until December, 1999 he was at the California Institute of Technology where he conducted research and taught courses in Power Electronics and Fundamentals of Energy Processing. During his 23 years at Caltech, more than 35 students obtained Ph.D. degree in Power Electronics under his guidance. From 2000 until present, Dr. Cuk continued his research contributions through TESLAco, the company he founded. Dr. Cuk is Fellow of IEEE and is the inventor of numerous switching converter circuits such as the Cuk converter, the TESLAconverter and many others.

Dr. Cuk is also the originator of the State-Space Averaging Method and more recently new switching methods: Hybrid Switching and Storageless Switching methods, which resulted in a number of ultra efficient, very compact and low cost switching converters for solar inverters, AC-DC battery chargers, data center power supplies and many other Power Electronics applications.

USC Power ResearchWorkshop:

Power Electronics

Dr. Slobodan Ćuk

November 18, 2011

1

2

PCSC ’70 and PCSC’71

Power Conditioning Specialists

PPESC’72

Power Processing and Electronics

PESC’73

Power Electronics Specialists

PCSC ’70 and PCSC’71

Power Conditioning Specialists

PPESC’72

Power Processing and Electronics

PESC’73

Power Electronics Specialists

What is in the name:What is in the name:

3

Sept. 2010: celebration of 100 years of Electrical

Engineering at Caltech

1910-1956: High Voltage Laboratory of Prof.

Sorensen

1970- 1999 Power Electronics Laboratory (Profs.

Middlebrook and Cuk)

Sept. 2010: celebration of 100 years of Electrical

Engineering at Caltech

1910-1956: High Voltage Laboratory of Prof.

Sorensen

1970- 1999 Power Electronics Laboratory (Profs.

Middlebrook and Cuk)

Electrical Engineering at Caltech Electrical Engineering at Caltech

4

Started in 1970 by Prof. Middlebrook

as second in nation after Duke 1968Both academic courses and research

program on a PhD level

PCSC’71 at Jet Propulsion Laboratory

PESC’73 at Caltech

Started in 1970 by Prof. Middlebrook

as second in nation after Duke 1968Both academic courses and research

program on a PhD level

PCSC’71 at Jet Propulsion Laboratory

PESC’73 at Caltech

Power Electronics at Caltech :Power Electronics at Caltech :

5

From 1970 – 1999

36 PhD students

1998: 11 PhD in Electrical Engineering out of

which 5 in Power Electronics

Prof. Middlebrook retired in 1998

Prof. Cuk semi-retired in 1999

From 1970 – 1999

36 PhD students

1998: 11 PhD in Electrical Engineering out of

which 5 in Power Electronics

Prof. Middlebrook retired in 1998

Prof. Cuk semi-retired in 1999

Power Electronics Group ( PEG) Power Electronics Group ( PEG)

6

NASA ( subcontract from TRW)

NOSC ( Naval Ocean System Center

(San Diego )

ONR- Office of Naval Research

IBM

Other companies

NASA ( subcontract from TRW)

NOSC ( Naval Ocean System Center

(San Diego )

ONR- Office of Naval Research

IBM

Other companies

First Sponsors 1974 and on First Sponsors 1974 and on

Boost Converter

CVg

+

-

Vg/(1-D)

R

CR

S

L

S

tTON T

OFF

TS

1973: Prof. Middlebrook sent me an

article with boost converter

7

8

Power Electronics-Emerging from Limbo1973 keynote by W.E. Newell, Westinghouse

Power Electronics-Emerging from Limbo1973 keynote by W.E. Newell, Westinghouse

9

State-space AveragingState-space Averaging

35 Years Anniversary 35 Years Anniversary

*Slobodan Ćuk; “MODELING, ANALYSIS, AND

DESIGN OF SWITCHING CONVERTERS”

Ph.D. Thesis, Caltech, November 1976

*R.D.Middlebrook and Slobodan Ćuk; “A general

Unified Approach to Modeling Switching-

Converter Power Stages, IEEE PESC, 1976

10

State-space AveragingState-space Averaging

35 Years Anniversary 35 Years Anniversary

*Slobodan Ćuk; “MODELING, ANALYSIS, AND

DESIGN OF SWITCHING CONVERTERS”

Ph.D. Thesis, Caltech, November 1976

*R.D.Middlebrook and Slobodan Ćuk; “A general

Unified Approach to Modeling Switching-

Converter Power Stages, IEEE PESC, 1976

11

1. Flux Balance on All Inductors

2. Charge Balance on All Capacitors

The State-space Averaging Uses Different Criteria

t

iC(t)

0

DTS

−

+

(1-D)TS

t

vL1(t)

0

DTS

(1-D)TS

−

+

−

+CR

V/Vg=D/(1-D)

RVg

C−+

L2

S

L1

1-DD

Ćuk Converter*

*US Patents: 4,184,197; 4,257,087; 4,274,133*US Patents: 4,184,197; 4,257,087; 4,274,133

t

vL2(t)

0

DTS

(1-D)TS

−

+

L1: Flux Balance L2: Flux Balance

C: Charge Balance

12

Flux Balance on L1

vL1 = DVg + (1-D)(Vg-VC)

Flux Balance on L1

vL1 = DVg + (1-D)(Vg-VC)

Flux Balance on L2

vL2 = D(VC-V) + (1-D)(-V)

Flux Balance on L2

vL2 = D(VC-V) + (1-D)(-V)

Charge Balance on Cr

iC = D(-I2) + (1-D)(I1)

Charge Balance on Cr

iC = D(-I2) + (1-D)(I1)t

iC(t)

0

DTS

−

+

(1-D)TS

I1

I2

t

vL1(t)

0

DTS

+

−

(1-D)TS

Vg

Vg-V

C

t

vL2(t)

0

DTS

+

−

(1-D)TS

V

VC-V

DC Solution: VL1 = 0; IC = 0; VL2 = 0 DC Solution: VL1 = 0; IC = 0; VL2 = 0

13

State-space Formulation of Flux and Charge Balances

vL1 = Vg

iC = -I2vL2 = VC-V

D ××××

State-space Averaging DC Model:

1. Multiply equations for ON-time by D2. Multiply equations for OFF-time by (1-D)3. Add together and set VL1=0, IC=0, VL2=0

1. Multiply equations for ON-time by D2. Multiply equations for OFF-time by (1-D)3. Add together and set VL1=0, IC=0, VL2=0

−

+C RV

g

C−+

L2

L1

−+ +−

−

+C RV

g

C−+

L2

L1

−+ +−

vL1 = Vg-VC

iC = I1vL2 = -V

ON-time Interval: OFF-time Interval:

{ (1-D) ××××{

Dynamic (Small Signal AC) Response

v V v x X x

d D d d D d

g g g= + = +

= + = −

$ ; $

$ ; ' ' $

$& $ $ $x Ax bvg

A A X b b Vgd= + + −

+ −

1 2 1 2

Steady-State

AX bVg++++ ==== 0

A DA D A==== ++++1 2'

b Db D b==== ++++1 2'

14

15

S C A M P

SwitchingConverterAnalysis andMeasurement

Program

SwitchingConverterAnalysis andMeasurement

Program

16

Coupled-Inductor Isolated Ćuk Converter

17

Manu Driven Graphics on First IBM-PC

From Paper at APEC Conference

18

Frequency Response – Loop Gain

19

Power Electronics Group exhibit at 1983 conference in San Diego

Power Electronics Group exhibit at 1983 conference in San Diego

20

Can your SCAMP program do this:

Enter desired frequency plot then

Draw the converter topology?

Can your SCAMP program do this:

Enter desired frequency plot then

Draw the converter topology?

Question asked:Question asked:

21

Can you enter desired DC voltage

gain such as V/Vg = D x D and:

DRAW ALL SUCH CONVERTERS:

Both known converters and

NEW (!!!) converter topologies?

Can you enter desired DC voltage

gain such as V/Vg = D x D and:

DRAW ALL SUCH CONVERTERS:

Both known converters and

NEW (!!!) converter topologies?

Related question:Related question:

CONFIDENTIALCONFIDENTIAL

22

S1

S2

S'1

S'2

L2

L1

C1

C2 RV

g

Computer Generated Converters*Computer Generated Converters*

*Dragan Maksimovic, “Synthesis of PWM and Quasi-resonant DC-to-DC Power Converters”, Ph.D. Thesis, January 12, 1989,

Caltech, Pasadena

*Dragan Maksimovic, “Synthesis of PWM and Quasi-resonant DC-to-DC Power Converters”, Ph.D. Thesis, January 12, 1989,

Caltech, Pasadena

If Solution to:

AX + bVg = 0exists, than:

Valid DC-DC Converters:

2 Inductors

1 Capacitor

2 States: ON&OFF

1 million possibilities} Only 30 Working

(Ćuk converter was there too !)

Only 30 Working(Ćuk converter was there too !)

AN EXAMPLE: (243, 146.2)

0

R

2

C1

C2

L1

1

Vg

L2

3

R

2

0

1

3L2

C2

L1

C1V

g

V C C L Lg 1 2 1 2

V C C L Lg 1 2 1 2

0

1

2

3

1

1

0

0

1

0

1

0

0

1

0

1

1

0

0

1

0

1

1

0

1 1

1

−−−− −−−−

−−−−

−−−−

−−−−

++++

↑↑↑↑ ↑↑↑↑

T E

H1 2444 3444

0

1

2

3

1

1

0

0

1

0

1

0

1

0

0

1

1

0

0

1

0

0

1

1

2 2

2

−−−− −−−− −−−− −−−−

−−−−

↑↑↑↑ ↑↑↑↑

T E

H1 2444 3444

23

Enumeration via Incidence Matrices

NEW CONVERTER

TL

2

C1

L1

C2

D2

D1

D3

M (D) = D2

( 243, 146.2 )

24

One Transistor, Three Diodes

Dr. Ćuk’s Power Technics 1988 cover Dr. Ćuk’s Power Technics 1988 cover

1988

ηηηη=83%

fs=500kHz

Ploss=20.5W

ββββ=20.5%

25

26

Power Electronics 117 class of 1998:TESLA temple prank

Power Electronics 117 class of 1998:TESLA temple prank

27

TESLAconverter

NCT converter

Hybrid Switching Method

Storageless Switching Method

Bridgeless PFC converters

Single-stage converters

Solar inverters

TESLAconverter

NCT converter

Hybrid Switching Method

Storageless Switching Method

Bridgeless PFC converters

Single-stage converters

Solar inverters

TESLAco years: 1999- presentTESLAco years: 1999- present

28

Isolated Full-bridge Buck Converter

Total of 8 Switches

C+

−R

S1

S2

S3

S4

D1 D

2

D3

D4

1:1

Vg

L

T

DVg

Two magnetic components

Square-wave Switching:

No 3 switches allowedEight needed for isolationNo capacitors

Hybrid-Switching Method:

3 switches onlyResonant capacitorResonant inductor

29

What about converters with 3 switches

30

CRS1

S2

2. A Resonant Capacitor

3. A Resonant InductorLr

1. Three Switches

Cr

31

“Birth ” of Hybrid-Switching Methodand Related Converter Topologies

“Birth ” of Hybrid-Switching Methodand Related Converter Topologies

#1#2 #4

#5#6

#7

#8#9#3

AC-DC

Converter Comparison

32

33

Conventional Three Power Processing Stage ApproachConventional Three Power Processing Stage Approach

C

LB

+

−R

S1

S2

S3

S4

D1 D

2

D3 D

4

n:1

vac

DB1

DB2

DB3

DB4

Cf

Lf

SB

+

−CB

DB

L48V400V

Polarity Inverting

DC-DC Converter

34

Boost Converter

CVg

+

-

Vg/(1-D)

R

CR

S

L

S

tTON T

OFF

TS

Problem

How to make a polarity inverting boost

converter 35

Polarity Inverting 3 Switch Boost Converter*

Vr=Vg/(1-D)

CSVg

L

-

+

LrI

L IC V

R

+ -Vr

I

CR2

CR1

Cr

Vg

L IL I

C

+ -Vr

CR2

Cr

S

S C-

+

LrI

C

R

+ -Vr

ICR1

Resonant

Discharge

Cr

*US Patent No. 7,778,046

OFF-time Interval (1-D)TS

V=Vg/(1-D)

V=Vr

36

Boost Converter

37

Positive and Negative Half-cycle of Input VoltagePositive and Negative Half-cycle of Input Voltage

Source Polarity Controls Conduction Interval of Two Diodes:

Full-Bridge Eliminated

Source Polarity Controls Conduction Interval of Two Diodes:

Full-Bridge Eliminated

S CVg

L

+

-

Lr

CR1

IL I

rCR

2 V

R

+ -VCr

IA

G

+

-

+

-

iS

D D

D'

Cr

S CVg

L

+

-

Lr

CR1

IL I

rCR

2 V

R

- +VCr

IA

G

-

+

-

+

iS

D D'

D

Cr

V=Vg/(1-D)

VCr=0

VCr=V

True Bridgeless

PFC Converter

38

39

True Bridgeless PFC Converter*True Bridgeless PFC Converter*

Cr

S C

L

+

-

Lr

CR1

iAC I

rCR

2 V

R

- +VCr

I

-

+

iS

vAC D

Input Voltage110V

THD=1.7%PF=0.999

*US and foreign patents pending*US and foreign patents pending

40

One Implementation of the Controlling SwitchOne Implementation of the Controlling Switch

Cr

C

L

+

-CR

1

IL I

rCR

2 V

R

+ -VCr

I

vAC

A

DS1

S2

Lr

ION

VOFF

I

III

DS1

S2

41

t

S

tTON T

OFF

vi, i

i

ii

vi

TS

Index "i" =1, 2, 3

Input Current Modulation for Each Phase at High Switching Frequency

Input Current Modulation for Each Phase at High Switching Frequency

42

Voltage and Current Waveforms in Ćuk-rectifierwith Integrated Magnetics Implemented

Voltage and Current Waveforms in Ćuk-rectifierwith Integrated Magnetics Implemented

Input Voltage110V

Input Voltage220V

THD=1.7%PF=0.999

THD=2.0%PF=0.991

43

Efficiency and Power Loss of Ćuk-rectifierEfficiency and Power Loss of Ćuk-rectifier

90%

91%

92%

93%

94%

95%

96%

97%

98%

99%

80 100 120 140 160 180 200 220 240

Input Voltage [V]

Effic

ienc

y

0.0

2.0

4.0

6.0

8.0

10.0

12.0

80 100 120 140 160 180 200 220 240

Input Voltage [V]

Pow

er L

oss

Demo #1:

400W Bridgeless

PFC converter 44

45

46

True Isolated

Bridgeless

PFC Converter 47

48

CR2

+

−CR

1S C

V

R

IM

Cr1

L

NP

NS

PFC IC Controler

iAC

Lr

Cr2

vAC

vAC, i

AC

iAC

vAC

t

S

tTON T

OFF

TS

True Bridgeless PFC Converter with Isolation*True Bridgeless PFC Converter with Isolation*


49

H

BS

+BS

-BS

2BS

True AC TransformerTrue AC Transformer

No Air-gapNo Energy StorageAutomatic ResetScalable to High Power

50

ComparisonComparison

Power Processing Single-stage Three-stage

Type of Converter Isolated Bridgeless PFC Bridge-Boost PFC-Full-

bridge

Switching Method HYBRID Square-wave

Number of switches 3 14

Switch-voltage Stress Low High

Lossless-switching YES NO

Control Simple Complex

Magnetics pieces 1 4

Power Losses 3% 10%

Efficiency >97% 88% to 90%

Size Small Big

Weight Light Heavy

Cost Low High

Three-PhaseAC-DC

Converter Comparison

51

52

v0

+VH

L1

i0

Q1 Q

2Q

3

Q4

Q5 Q

6

C

L3

L2

v240

Present Approach: Two StagesPresent Approach: Two Stages

Three-phase properties prematurely

lost after rectification and PFC control

First Stage: Rectification and PFC

Efficiency = 98%

First Stage: Rectification and PFC

Efficiency = 98%

53

C C+

−R

n:1

L V+VH

S1 S

2

S3 S

4

D1 D

2

D3 D

4

Second Stage: Isolated DC-to-DC converter Second Stage: Isolated DC-to-DC converter

Second Stage: DC Isolation

Efficiency = 95%

Second Stage: DC Isolation

Efficiency = 95%

Power processed sequentially in Two stages so

Low Total Efficiency of 92%

New Single-stage

Three-phase Rectifier

54

55

56

57

v1

Isolated Bridgeless PFC

Phase 1

+V

v2

v3

R

i01 i

0

i02

i03

i1

i2

i3

nCIsolated Bridgeless PFC

Phase 2

Isolated Bridgeless PFC

Phase 3

New Direct Three-Phase to DC Conversion with PFC and Isolation in a Single Stage

New Direct Three-Phase to DC Conversion with PFC and Isolation in a Single Stage

Power processed in parallel and not in series

Each Phase Efficiency 98%; TOTAL Efficiency 98%Each Phase Efficiency 98%; TOTAL Efficiency 98%

98%

98%

98%

58

CR2

+

−CR

1S C

V

R

Cr1

L

NP

NS

Islolated

Bridgeless PFC IC

ii

vi

Lr

Cr2

AC-DC Converter for Each Phase with PFC and Isolation*AC-DC Converter for Each Phase with PFC and Isolation*

Three Switches OnlyThree Switches Only

*US Patent No. 7,778,046*US Patent No. 7,778,046

59

v1 v

2

v3

R

i1

i2

i3

nBridgeless

3-phase Isolated

PFC Converter

C

3-phase Isolated

Bridgeless PFC IC

Three-Phase Ćuk-rectifier with PFC IC Control

Three-Phase Ćuk-rectifier with PFC IC Control

60

0

0.25

0.5

0.75

1

1.25

1.5

1.75

0 60 120 180 240 300 360

po1, p

o2, p

o3, P

P

po3

po1

po2

Sum of Instantaneous Output Powers of Three Phases is Constant

Sum of Instantaneous Output Powers of Three Phases is Constant

61

0

0.25

0.5

0.75

1

1.25

1.5

1.75

0 60 120 180 240 300 360

io1,io2,io3,I

I

io3

io1

io2

Sum of Instantaneous Output Currents of Each Phase is Constant

Sum of Instantaneous Output Currents of Each Phase is Constant

62

t0

v(t)

V

t0

i01+ i

02+ i

03I

i0(t)

V = constant

P = constantI = constant

Constant Output Power and Constant Output Voltage Lead to Constant Output Current

Constant Output Power and Constant Output Voltage Lead to Constant Output Current

63

“Birth ” of Storageless Switching Methodand Related Converter Topologies

“Birth ” of Storageless Switching Methodand Related Converter Topologies

#1#2 #4

#5#6

#7

#8#9#3

Demo #2:

200W DC-DC converter

48V to 24V

64

Power Stage of 200W Storageless Converter Power Stage of 200W Storageless Converter


65

Bi-directional Specifications

Switching Frequency: 50kHz

Input Voltage: 48V

Output Voltage: 24V

Output Current: 4A

Power: 200W

Volume : 0.2in3

Power Density: 1kW/in3

No Heat SinkNo Heat SinkNo Heat SinkNo Heat Sink

No Forced Air CoolingNo Forced Air CoolingNo Forced Air CoolingNo Forced Air Cooling


66

67


200W, 48V/24V Storageless Ćuk-buck Converter200W, 48V/24V Storageless Ćuk-buck Converter

Efficiency of 200W Storageless Converter Efficiency of 200W Storageless Converter

Efficiency vs Output Power

97.0%

97.5%

98.0%

98.5%

99.0%

99.5%

100.0%

0 25 50 75 100 125 150 175 200

Output Power (W)

Efficiency


68

69

Power Stage of 750W, 48V Prototype*Power Stage of 750W, 48V Prototype*

Efficiency over 99%Efficiency over 99%


Storageless Buck ConverterStorageless Buck Converter

70

Efficiency of 750W, 100V to 48V ConverterEfficiency of 750W, 100V to 48V Converter

98.0%

98.5%

99.0%

99.5%

100.0%

2 3 4 5 6 7 8 9 10 11 12 13 14 15

Iout (A)

Eff

icie

nc

y

71

Isolated Storageless Converter*Isolated Storageless Converter*


72

360V to 24V Efficiency

75.00%

80.00%

85.00%

90.00%

95.00%

100.00%

0.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00

Output Power (W)

Eff

360V to 24V Efficiency

Efficiency of Isolated Storageless Converter Efficiency of Isolated Storageless Converter

98.2% efficiency

73

Green Dream Power Technology™Green Dream Power Technology™

v1 v

2

v3

R

i1

i2

i3

n 3-phase Isolated

Bridgeless PFC

C

3-phase Isolated

Bridgeless PFC IC

3 switch-

buck

non-isolated

3 switch

POL

48V 12V 1V

Efficiency 98% 99% 97%

Switchingmethod Hybrid Storageless POL

74

Applications SummaryApplications Summary

- Computer servers

Battery chargers for electric cars and bycycles

- Desktop computers

- AC Adapters, projectors, etc.

-Solar photovoltaic conversion

-LED lighting

VRM (12V to 1V regulators)

75

Applications SummaryApplications Summary

-Wide range of power

-From cell hones and under a one 1 Watt to 100kW for electric drive for motors, etc.

76

July 10, 2010 : Memorial for Professor Middlebrook July 10, 2010 : Memorial for Professor Middlebrook

77

July 10, 2010 : Power Electronics Group Members and their relatives

July 10, 2010 : Power Electronics Group Members and their relatives

Documents

Power electronics - University of Southern Californiaalevi.usc.edu/Html/publications/PRW Cuk_TESLAco.pdf · Power electronics Slobodan Cuk came to Caltech in 1974 and obtained his