COMPANY CONFIDENTIAL 1

3kW PFC for Electrical Car Charger

Alex Lollio, Global Rotation Engineer

Automotive Products Business UnitPavia Design Centre, Italy

October, 2012 - April, 2013

Project Manager : Davide GiacominiProgram Mentor : Massimo Grasso

COMPANY CONFIDENTIAL

Outline

• Introduction• Electrical Car Charger

• PFC Topologies

• IR Portfolio

• Overview of the IR115x PFC Controller

• 3kW Interleaved PFC Demoboard Realization Steps:• FIRST STEP: Current Sense Transformers

• SECOND STEP: Clock Synchronization and Interleaving

• THIRD STEP: Current Sharing

• Measurement Results• Board Image and Specifications

• Measurement Results (PF, Efficiency, Input Current after Load Step)

• IC Pinout Proposal

• Conclusion

COMPANY CONFIDENTIAL

Level 1: OnBoard Charger

Level 3:

Charger Station

1.5kW < Power < 3.5kW

16h < Charge Time < 7h

Level 2:

External Charger

3.5kW < Power < 10kW

7h < Charge Time < 2.5h

10kW < Power < 25kW

2.5h < Charge Time < 1h

Electrical Vehicle Charger Classification

http://avt.inl.gov/pdf/phev/phevInfrastructureReport08.pdf

Charge Time for 25kWh battery

COMPANY CONFIDENTIAL

Level 1 AC/DC Onboard Charger

Each Electrical Vehicle has an Onboard charger :

• High volume addressable market

• The target power is between 1.5kW and 3.5kW

• AC input : 16A@140V/240V → 2.2kW/3.8kW(www.imsresearch.com)

• DC Output: 200 - 450V

AC SOURCEAC/DC PFC DC/DC High Voltage

Battery

AC/DC PFC IS THE FOCUS OF THIS WORK

ONBOARD CHARGER

140V - 240V 200V - 450V

+

-

COMPANY CONFIDENTIAL

Power Factor Correction: Working Principle

The goal of the PFC is to obtain a phase alignment between the input voltage and input current

AC INPUT 140V/240V

385V DC OUT

385V0V

CONTROLLER

• PFC Figure of Merit → PF = P/(VRMS x IRMS) = Watts/V.A.

• The switch is the mayor contributor of switching loss (20kHz<FS<150kHz)

• The diode works in hard switching mode (reversed current when turning OFF)

CurrentVoltage

LEGEND

COMPANY CONFIDENTIAL

Interleaved PFC: Working Principle

VIN

L1

COUT

VO

RLOAD

L2

IIN

S1

S2

I1

I2

ICOUT

IOUT

Benefit of interleaving:

• Input Ripple Current reduction

• Output Ripple Current reduction

• Better thermal management

• Core Magnetic size halved

ESINGLE = ½LIIN²EINTERLEAVED = ½L(IIN/2)² + ½L(IIN/2)² = ¼LIIN²

S1

S2

ΔIL1

ΔIL2

IIN=IL1+IL2

I1

I2

ICOUT

IIN/2

COMPANY CONFIDENTIAL

Electrolytic Capacitor lifetime PFC

Dual Phase PFC

Single Phase PFC

EPCOS B43740

Lifetime of the output capacitor is doubled in the interleaved PFC

COMPANY CONFIDENTIAL

IR Portfolio

IR products for Interleaved PFC Application:

L1

COUT

VO

RLOAD

L2

IIN

S1

S2

I1

I2

ICOUT

IOUT

CONTROLLER

CONTROLLER

• IGBT

• Controller IR115x Family

Single Phase PFC

The Goal of this work is to adapt the IR115x Single Phase PFC Controller to a Dual-Phase Interleaved

PFC Implementation

COMPANY CONFIDENTIAL

Outline

• Introduction• Electrical Car Charger

• PFC Topologies

• IR Portfolio

• Overview of the IR115x PFC Controller

• 3kW Interleaved PFC Demoboard Realization Steps:• FIRST STEP: Current Sense Transformers

• SECOND STEP: Clock Synchronization and Interleaving

• THIRD STEP: Current Sharing

• Measurement Results• Board Image and Specifications

• Measurement Results (PF, Efficiency, Input Current after Load Step)

• IC Pinout Proposal

• Conclusion

COMPANY CONFIDENTIAL

3kW PFC Demoboard block diagram

L1

COUT

VO

RLOAD

L2

IIN

S1

S2

I1

I2

ICOUT

IOUT

IR1155

IR1155

CURRENT SHARINGCLOCKINTERL.

• Current sensing is implemented using four current transformers (CT)

• Current sharing is implemented using a differential opamp

• Clock interleaving is implemented using two comparators LM393

Specs:

• VIN: 120V/240V

• Max IIN: 16A

• VOUT: 385V

• L: 250uH

• COUT: 3mF

• Freq: 50kHz

CT

CT

COMPANY CONFIDENTIAL

3kW PFC Demoboard Image

IGBT Diode

IGBT Diode

INDUCTORS

BRIDGE RECT

1155

AC IN OUT

Specs:

• VIN: 120V/240V

• Max IIN: 16A

• VOUT: 385V

• L: 250uH

• COUT: 3mF

• Freq: 50kHz

• IGBT: AUIRGP65

• DIODE: ETX1506

33cm

27cm

INTERL.

CUR. SH.

CT LOAD

VCC

COMPANY CONFIDENTIAL

Summary of the Project

• Oct : Study of PFC literature and IR products

• Nov : Microcap model realization of the IR1155

• Dec : Interleaving of two IRAC300 Demoboard + documentation

• Jan : 3kW Demoboard Schematic and Layout realization

• Feb : PCB assembly and measurements collecting

• March : Demoboard second release (Schematic + Layout)

• Apr : • Documentation (application note, user guide, patent)

• Additional activities (Horn test software, LabView courses)