Robust Control Algorithm for Light Electric Vehicle Onboard Charging System

This paper deals with a multi-source light electric vehicle (LEV) onboard charger (OBC) having the bidirectional capability with an improved phase shift control. The AC grid, a solar photovoltaic (SPV) array and a battery energy storage (BES) are different sources used in this work. This two-stage charger is required to regulate the output power with an appropriate control of the voltage. The front-end converter is a boost converter used for maximum power point tracking (MPPT) of a SPV array and second stage comprises of a dual active bridge (DAB). A voltage source converter (VSC) is used to connect the charger. Moreover, a buck-boost converter is used to regulate the power flow in/from the BES in a charging station. The design of high frequency transformer for DAB, is required to consider the selection of leakage inductance. A bidirectional charger of a 1.1 kW power transfer capability is designed. An improved phase shift control of second stage converter is used to regulate the output during disturbances from the source side and a pulse width modulation (PWM) control is used to regulate the DC link voltage.