An EV battery charger with power factor corrected bridgeless zeta converter topology

Abstract

An EV (Electric Vehicle) is becoming more popular these days in transport sector due to its environment friendly operation as well as availability at reduced cost. The battery charging process is the prominent matter of concern in an EV because of power quality issues in the input current drawn by the charger. These issues are generated mainly because of the nonlinear nature of the diode bridge rectifier (DBR), used at the input side of the charger for AC-DC conversion. The abovementioned problem is minimized if the DBR is eliminated at the input, along with added advantage of reduced conduction loss in the circuit. Therefore, this paper proposes a bridgeless isolated PFC (Power Factor Corrected) based EV battery charger with a zeta converter topology which uses constant current/constant voltage mode control for the battery charging. The proposed bridgeless converter is designed to follow IEC-61000-3-2 PQ (Power Quality) standard i.e. it draws a perfect sinusoidal input current with low THD from AC mains with all the advantages of zeta converter topology like low output ripple voltage, a non-inverted output, stable output response and effective control. Therefore, the overall efficiency is improved for the proposed front end bridgeless converter. MATLAB/Simulink based model is developed which is used to verify the performance of the proposed bridgeless zeta converter at rated condition as well as fluctuations in the supply voltage. The converter' performance is evaluated with a 48V 100Ah lead acid battery being used in EV which exhibit an improved power quality indices for the source current that is well within international PQ limits.