Constant Current Charging of EV Battery with Zero Back-Flow Power EPS Control using DAB Converter

Abstract

This paper deals with the constant current (CC) charging of the Electrical Vehicle (EV) battery using a dual active bridge (DAB) converter. These are also extensively used in DC microgrid applications due to its bidirectional power flow poten-tiality, galvanized isolation, and implicit zero voltage switching (ZVS) characteristics. Among various modulation schemes used for the control, single phase shift (SPS) method has disadvantage of back-flow power, which decreases the efficiency due to increase of the switching stresses. The DAB is simulated using extended phase-shift (EPS) modulation technique to achieve the CC mode with zero back-flow power. The detailed analysis and operation of EPS control with CC charging mode are delineated. Simulation results for a 2 kW, 96 V/55 V electric vehicle (EV) battery in buck mode operation are presented. This system can be extended further for bidirectional power flow using ZVS switching in both grid to vehicle (G2V) and vehicle to grid (V2G) modes with experimental validation.