Evaluation of topologies for a solar powered bidirectional electric vehicle charger

Abstract

Charging of electric vehicles (EVs) from solar energy provides a sustainable means to power EVs in the future. A comparison of topologies for a three-port converter to charge EVs directly from photovoltaic (PV) panels is presented in this study. The grid-connected EV charger has a nominal rating of 10 kW and is bidirectional, enabling vehicle-to-grid operation. The topologies are optimally designed considering different switching frequencies, silicon carbide devices, magnetic cores and number of interleaved stages. Nine topologies are compared using a comparison framework, and the best topology is chosen based on the number of components, converter efficiency, volume, controllability and current ripple. The analysis shows that the best topology is a three-port converter with a central direct current link with a 3-leg interleaved boost converter (IBC) for the PV, two-level inverter with sinusoidal modulation for the grid and a 4-phase interleaved flyback converter for the EV. The loss models built are experimentally verified using a 3-leg IBC.