Design and Analysis of Bidirectional Dc-Dc Converter for Electric Vehicle Application

Abstract

This project presents design and analysis of a bidirectional DC-DC converter it is suitable for power electronic interface between the main energy storage system and the electric traction drive in hybrid electric vehicles. A hybrid energy storage system composed of a battery unit and an ultra-capacitor pack is considered. A parallel dc-linked multi input converter with a half-bridge bidirectional DC-DC cell topology is chosen to link the battery/ultra capacitor storage unit with the dc-link. The paper focuses on modeling the proposed converter for both dynamic and steady state analysis. Averaging and linearization techniques are applied to obtain the averaged state space models and small signal models of the converter in both boost and buck operation modes. A criterion for sizing the converter passive components based on the imposed design specifications and constraints is illustrated. Simulation results of the buck-boost converter during normal functioning and under faulty conditions are presented. In particular, short-circuit faults and open-circuit faults of diodes and transistors are analyzed.