Inverse sinusoidal pulse width modulation switched electric vehicles’ battery charger

Abstract

This paper presents an efficient, cost-effective and sustainable grid-connected electric vehicles’ (EVs’) battery charger based on a buck converter to reduce the harmonics injected into the mains power line. To utilize the switching converter as an effective power factor controller (PFC), inverse sinusoidal pulse width modulation (ISPWM) signals are applied. However, a mathematical relationship between the sending-end power factor and the duty ratio of the switching buck converter is derived. To ensure the sustenance of the proposed method, a simulation model of the battery charging system is tested in PSIM simulation platform. The simulation results yield to a loss-less charging system with a sending-end power factor close to unity. An experimental testbed comprising a 60 V battery bank of 100 A-h capacity with a charging current of 7 A is developed. The laboratory assessments present an 88.1% efficient charging prototype with a resultant sending-end power factor of 0.89. The laboratory framework concerns with the comparative analysis of the sending-end power factor, system efficiency, and mains line current total harmonic distortion (THD) obtained for different charging methods - simple battery charger, fixed duty ratio controlled buck converter and the proposed topology. The performance evaluations corroborate the reliability of the presented work.