Zvs dc-dc converter for PHEV charger

A ZVS DC–DC converter for PHEV Charger

OVERVIEW

Area of project work

Introduction

Design objectives

Circuit diagram

Modes of operation

Simulation results

References

3/31/2014A ZVS DC-DC CONVERTER FOR PHEV CHARGING2

AREA OF PROJECT WORK


Developing a DC-DC converter

Hybrid electric vehicle charger

Soft switching

INTRODUCTION


Plug-In Hybrid Electric Vehicles

Plug-in hybrid electric vehicles have an internal combustion engineand an electric motor, which uses energy stored in batteries.

Advantages in fuel economy

Less environmental impact over conventional automobiles

Onboard charger - responsible for charging the battery pack



Simplified block diagram of a universal battery charger

2 stages of conversion for a battery charger:

1. AC-DC PFC boost conversion2. DC-DC converter with output filter

Problems faced by existing topologies


Limited ZVS range

Reduction in power transfer capability

Voltage spike across rectifier diodes

Increased component count


DESIGN OBJECTIVES

1.65 KW on board charger for PHEV

Low cost

Minimizing charger size

High efficiency

CIRCUIT DIAGRAM


MODES OF OPERATION


Assumptions:

1. Resonant inductor include the leakage inductance

2. Output rectifier is ideal

3. All parasitic capacitances(winding &heat sink capacitances) are lumped with switch output capacitance.

MODES OF OPERATION

MODE 1(t0-t1)

DCM


Using KVL

Taking initial condition,


Mode 2(t1-t2)

DCM


Taking initial condition,

Inductor current


Mode 3(t2-t3)

DCM

Parasitic capacitances of DR1 and DR4 resonates with Lr


Mode 4(t3-t4)

DCM


Mode 5(t4-t5)

DCM


Mode 6(t5-t6)

DCM

Parasitic capacitances of DR2 and DR3 resonates with Lr


MODE 1(t0-t1)

CCM


Mode 2(t1-t2)

CCM


Mode 3(t2-t3)

CCM


Mode 4(t3-t4)

CCM


Mode 5(t4-t5)

CCM


Mode 6(t5-t6)

CCM


Drawbacks of CCM operation:

Larger resonant inductor value required

Transformer turns ratio increases

Voltage stress on primary switches increases

SIMULATION


MatLab Simulink Model

•Output voltage


•Voltage across AB node



•Current through Lr

RESULTS OF SIMULATION


DCM operation:

ZVS turn ON for Q3 and Q4

Near zero current switching of Q1 and Q2

Voltage spikes across diodes are eliminated

Natural lossless commutation of rectifier diodes

GANTT CHART


Sl.No TASK NOV DEC JAN FEB MARCH APR MAY

1

Searching various topics.Selecting and sorting paper

2

Got approved Reference study, Literature survey

3

Modeling and simulation

4

Designing, Hardware implementation and testing

5

Studying practical feasibility

6 Report writing

REFERENCES


Base paper:

[1] Deepak S. Gautam, Fariborz Musavi,Wilson Eberle and William G. Dunford,”A zero- voltage switching full-bridge dc–dc converter with capacitiveoutput filter for plug-in hybrid electric vehicle battery charging”, IEEETrans. on power electronics, vol. 28, no. 12, December 2013.

Reference papers:[2] M. Pahlevaninezhad, P. Das, J. Drobnik, P. K. Jain, and A. Bakhshai, “Anovel ZVZCS full-

bridge DC/DC converter used for electric vehicles,”IEEE Trans. Power Electron., vol. 27, no. 6, pp. 2752–2769, Jun. 2012.

[3] D. Gautam, F. Musavi, M. Edington, W. Eberle, and W. G. Dunford, “An automotive on-board 3.3 kWbattery charger for PHEV application,” IEEE Trans. Veh. Technol., vol.61, no. 8, pp. 3466–3474, Oct. 2012.

[4] M. Ordonez and J. E. Quaicoe, “Soft-switching techniques for efficiency gains in full-bridge fuel cell power conversion,” IEEE Trans. Power Electron., vol. 26, no. 2, pp.482–492, Feb. 2011


ZVS Capability


ZVS achieved by providing inductive current during ON and snubber capacitor across switches during OFF

Loss of ZVS causes:

High switching losses

Very high EMI

Noisy control

Voltage spike across rectifier diodes


•Rectifier connects 2 inductances(current courses)

•RCD snubbers used to mitigate voltage spikes

•Large amount of losses in snubberresistance

•Efficiency of the converter decreases

Engineering

Zvs dc-dc converter for PHEV charger