MODELING,ANALYSISANDCONTROLOFPOWER CONVERTERTOPOLOGIESFOREVCHARGING APPLICATIONS

Abstract

With the recent rise of EVs, demand for better, reliable performing chargers with more efficiency is increasing. Role of converters is crucial in Electric Vehicle charg ers to efficiently convert power, improve power quality, and safely operate the battery charging. In this thesis, a modelling, analysis, control and comparison of some power factor correction coverters (PFC) and two isolated dc-dc converters that can be used for EV chargers are carried out. For the first rectification stage in front end, three different PFC converters;Boost PFC, Interleaved Boost PFC and Flyback PFC, are modeled and simulated in MAT LAB/Simulink. Power Factor improvement, THD, output voltage ripple, regulation and conversion efficiency are observed for each topology and a comparative study be tween these three converters is carried out. From the studies that the Interleaved Boost PFC offers an advantage for reducing source current ripple & improves sharing of the current in switches, with less harmonics. Flyback PFC converter is used with galvani cally isolated stage for low to medium power chargers. For the second stage, FBC and PSFB topologies are studied. Performance evalu ation, like voltage regulation, switching features, and power capacity were compared along with power transfer capability and efficiency. The FBC offers efficient power transfer with isolated stages, and is effective for mid to high level power chargers. PSFBprovidesimproved efficiencyandreduces theswitching stressesusingsoft-switching. Finally, comparison is done between all mentioned topologies in order to select ap propriate converter configuration.