design and simulation of power converters

8/3/2019 Design and Simulation of Power Converters

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Design and

Simulation ofPower Convertersusing the AnsoftPower Suite

Presenter: Roberto Prieto

Universidad Politcnica de Madrid (UPM). Spain


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Outline

The application: Interleaved converters

Design of magnetic components for power conv erters usingconverters using PExprt

Advantages of Integrated magnetics in InterleavedConverters

Integrated magnetics component design using PExprt

Converter design, including regulation loop: from PExprt toPExprt to Simplorer

Digital control implementation with Simplorer

System design: from the circuit level to the system levellevel


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Ansoft Power Suite


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Interleaved Converters Features

LoadLoadParalleling

Shift

Packaging

+

+


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IIL1L1

LL11

IIL2L2

LL22

Ripple cancellation

Ripple cancellationRipple cancellation

2 converters2 converters d = 50%d = 50%

4 converters4 converters d = 25%d = 25%

IIL1L1

IIL2L2

IICC

IIL1L1

IIL2L2

IICC

Small COUT

Small COUT

Advantages of Interleaved Converters (I)


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Advantages of Interleaved Converters (II)

Vs = 24V, Is = 10AVs = 24V, Is = 10A

Vs = 9V, Is = 10AVs = 9V, Is = 10A


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LoadLoad

IIN/N

Advantages of Interleaved Converters (III)


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Application of Interleaved Converters

AmpRF

PowerConverte

r

Filter

Control


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42V

DC-DC

12V

High LowD

C-DC

400V

DC-DC

12V

Interleaved converters: Automotive

application


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80.00

82.50

85.00

87.50

90.00

92.50

95.00

97.50

100.00

0 10 20 30 40 50 60 70

Output current (A)

Effici

ency(%)

Only power stage

Power stage + control

Phase currents

-0.5

0

0.5

1

1.5

2

0.0E+00 5.0E-06 1.0E-05 1.5E-05 2.0E-05 2.5E-05t (s)

a

se

currents

Phase currents

-0.5

0

0.5

1

1.5

2

0.0E+00 5.0E-06 1.0E-05 1.5E-05 2.0E-05 2.5E-05t (s)

a

se

currents

Very small size

components

SMD is possibleSMDSMD is possibleis possible

SMDSMD

Output capacitorsOutput capacitors

Automotive Application: Multi-phase converters.36 phases

I l d C d i i h


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Interleaved Converters design withSimplorer (I)

SMPS Library elementsSMPS Library elementsSMPS Library elements


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SMPS library contains aSMPS library contains awide list of averagedwide list of averaged

and switch level modelsand switch level models

Simplorer SMPS library


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Magnetic Component design with PExprt (I)


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Design with PExprt. Step 1: Design


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PExprt. Step 2: Select & Compare


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PExprt. Step 2: Select & Compare


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PExprt. Step 3: Optimize

PE t St 4 Ci it l l i l ti ith


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PExprt. Step 4: Circuit level simulation withSimplorer


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-1.00

1.00

0

949.27u 999.90u960.00u 980.00u

Phase Currents

0

1.00

00.00m

0 10.005.00

max 84%

Decrease due to

parasitic effects0

1.00

500.00m

0 10.005.00

2.00

5.00

3.00

4.00

9.95m 10.00m9.96m 9.98m

1.6A p-p1.5A p-p

86%

Comparison of models at circuit level with Simplorer

EfficiencyEfficiencyEfficiency

Current at each phaseCurrent at each phaseCurrent at each phase

Integrated Magnetics vs Discrete


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Integrated Magnetics vs Discrete

Components

-12.27

13.98

0

10.00

360.05u 400.00u370.00u 380.00u 390.00u

Phase Currents

-2.00

2.00

0

360.08u 400.00u370.00u 380.00u 390.00u

Phase Currents

0

4.94

2.00

4.00

0 800.00u500.00u

Output Voltage

0

5.23

2.00

4.00

0 800.00u500.00u

Output Voltage

Discrete ComponentsDiscrete ComponentsDiscrete ComponentsIntegrated MagneticsIntegratedIntegrated MagneticsMagnetics

Integrated Magnetics Features in Interleaved


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Multiphase

converters

MultiphaseMultiphase

convertersconvertersMagnetic

integration

MagneticMagnetic

integrationintegrationCouplingCouplingCoupling

Multiphase transformer(several implementations)

i0

Loadv1

v2

v3

i1

i2

i3

i4

Integrated Magnetics Features in InterleavedConverters (I)



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iO Loadv1

v2

v3

i2

i3

Standard cores

Integrated Magnetics Features in InterleavedConverters (II)



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Core ACore A Core BCore B

Windingphase 2

Windingphase 4

Winding phase 3 Winding phase 1

Winding phase 4

Core ACore A

Core BCore B

Phase 1

Phase 2

Phase 3

Phase 4

Core ACore A

Core BCore B

Volume comparison

0%

25%

50%

75%

100%

125%

Decoupled

inductor

Integrated

transformer +

additional inductor

Integrated

transformer

Integrated Magnetics Features in InterleavedConverters (III)


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FeaturesFrequency dependent

Capacitive effects

Nonlinear core

Design of Integrated Magnetics with PExprt


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Fl ibl Wi di S t D fi iti f h l


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Flexible Winding Setup Definition for each core leg


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PExprt Model: Simplorer link

Diff t b bbi b i d t h l


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Different bobbins can be assigned to each core leg

Planar Integrated can also be defined


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Planar Integrated can also be defined


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p

n

mMOSFET_LEG

M1

M2

pwm

pwm1

p

n

mMOSFET_LEG

M1

M2

pwm

pwm2

p

n

mMOSFET_LEG

M1

M2

pwm

pwm3E1

PEX

PExprtLink1

R1

A

AM1

A

AM2

A

AM3

C1

STEP1

Circuit level simulation with Simplorer


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1.00

1.00

0

949.27u 999.90u960.00u 980.00u

0

1.00

00.00m

0 10.005.00

max 84%

1.5A p-p

Comparison of models at circuit level with Simplorer

2.00

.00

0

2.50

5.00

0 1.02m500.00u

0

1.00

00.00m

0 10.005.00

More stable behavior

84%

2.00

2.00

0

949.27u 999.90u960.00u 980.00u

The currents are in phase

2.2A p-p

2.0

.00

0

2.50

5.00

0 1.02m500.00u

Faster than the uncoupled version

p

n

mMOSFET_LEG

M1

M2

pwm

pwm1

p

n

mMOSFET_LEG

M1

M2

pwm

pwm2

p

n

mMOSFET_LEG

M1

M2

pwm

pwm3E1

PEX

PExprtLink1

R1

A

AM1

A

AM2

A

AM3

C1

STEP1

DiscreteDiscreteDiscrete IntegratedIntegratedIntegrated


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Particular geometries might require Maxwell 3D

2D is feasible2D is feasible2D is feasible

3D is necessary3D is necessary3D is necessary

Automotive Application: Multi phase converters


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Digital control is mandatoryDigital controlDigital control is mandatoryis mandatory

Automotive Application: Multi-phase converters.36 phases


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G(s)G(s)Continuous blocks: S-Transfer function

Discrete blocks: Z-Transfer function

Discrete Fixed-Point : Synthesized VHDL code

Control Implementation: Alternatives

11

AnalogAnalogAnalog

DigitalDigitalDigital

22

33

G(z)G(z)

Discrete_PID


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Digital Control for multiphase Converters

f = 3kHzf = 3kHz


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Output Voltage

Duty Cycle

Digital Control Implementation

Soft Start

(Electric circuit)Simplorer blocks

Analog PID

AnalogImplementationAnalogImplementation


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Output Voltage

Duty Cycle

Soft Start

(Electric circuit)

Discrete PID(VHDL-AMS block)

Simplorer blocks

Digital Control Implementation

DigitalImplementationDigitalImplementation


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2.50

3.50

3.00

250.00u 450.00u300.00u 400.00u

Output Voltage

-10.00

20.00

0

10.00

250.00u 450.00u300.00u 400.00u

ase urrents

2.50

3.50

3.00

250.00u 450.00u300.00u 400.00u

Output Voltage

-10.00

20.00

0

10.00

250.00u 450.00u300.00u 400.00u

Phase Currents

Digital Control Implementation: Simplorer Results

Continuous time P ID (Analog)Continuous time P ID (Analog)Continuous time P ID (Analog)

Discrete time P ID (Digital): sampling = 600kHzDiscrete time P ID (Digital): sampling = 600kHzDiscrete time P ID (Digital): sampling = 600kHz

Digital Control Implementation: Simplorer based


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Overshot and settling timemeasurement

Performance evaluation(better when settling time is short)

Fitness functionInitial simulations

Tendency ofthe parameters

Digital Control Implementation: Simplorer baseddesign

S S S


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Complete systemComplete system Power systemPower system

The power system inv olves:

involves:Losses

Dynamic limitations

Temperature issues

Failures

The power system can not beThe power system can not be

modeled as an ideal systemmodeled as an ideal system

System and Sub-System levels

M d li h


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Switch level modelsAre based directly on the structure

Provide information for eachcomponent in every switching

cycle

Averaged models

Switching information is lost butstructure is kept

There are several techniques like:

State space averaging

Averaged switch modeling

Behavioral modelsBased on the input-outputbehavior

The model is a black box, the real

structure is lost

Modeling approaches

Sim lation time


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Simulation time

Voutn

Voutp

Vinn

Vinp

Half BridgeRegulado

28V/1.8V

Vom

Vop

Vinm

VinpBuck

Regulado42V/28V

+

V

VM2

Voutn

Voutp

Vinn

Vinp

Half BridgeRegulado

28V/1.8V

Voutn

Voutp

Vinn

Vinp

Half BridgeRegulado

28V/1.8V

Vom

Vop

Vinm

VinpBuck

Regulado42V/28V

Vinm

Vinp

SubsistemaBateria

Vm

Vp

SubsistCargasReg2

Vm

Vp

SubsistemaGenera

Vm

Vp

SubsistemaCargasNoR

Vm

Vp

SubsistCargasReg

Vm

Vp

SubsistemaCargasNoReg2

+

V

VMc

+

V

VMc

+

V

VMba

A

AMba

+

V

VMin

0

43.00

10.00

20.00

30.00

0 150.00m25.00m 50.00m 75.00m 100.00m

Simulation time

-Averaged models -> 157 seconds

-Behavioral models -> 29 seconds

5 times faster!!!

SMPS Lib PT l


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Problems designing power systemsThe lack of models for each DC/DC converterThe lack of information on commercial converters

Difficulty to develop the models

Long simulation time

All above problems multiplied by the number of converters

Get optimized VHDLGet optimized VHDL--AMS models for DC/DCAMS models for DC/DC

converters in minutesconverters in minutes

SMPS Library: PTool

SMPS Lib PT l


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SMPS Library: PTool

Input characteristicsInput characteristics

Output characteristicsOutput characteristics

Dynamic responseDynamic response

Static responseStatic response

Remote controlRemote control

Thermal behaviorThermal behavior

ProtectionsProtections

Power sharingPower sharing

Cross regulationCross regulation

PToolPTool converterconverters features:s features:

Simplorer S stem Le el Models


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Simplorer System Level Models

vi_n

vi_p

vo1_n

vo1_p

Behavioral



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vi_n

vi_p

vo1_n

vo1_p

Behavioral

0

100.00

50.00

0 10.005.00

Efficiency comparison

Behavioral

Switch level

0

3.40

2.00

0 520.00u200.00u 400.00u

System Level and Switch

Total simulation time: 700us

Behavioral: 0.992s Switch level: 352.54s


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design and simulation of power converters

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