A 10kW Solar-Powered Bidirectional EV Charger Compatible with Chademo and COMBO

Abstract

Charging electric vehicles (EVs) from photovoltaic panels (PV) provides a sustainable future for transportation. This paper presents the development of a 10kW EV charger that can be powered from both a PV array and the three phase AC grid. The goal is to realize a high power density and high-efficiency three-port power converter that integrates the EV, PV, grid and meets the Chademo and CCS/Combo EV charging standards. The EV port is designed to be isolated and bidirectional, so that both charging and vehicle-to-Grid (V2G) can be implemented. As PV and EV are both DC by nature, the converter uses a central DC-link to exchange power between the EV and PV, thereby increasing efficiency. The use of silicon carbide devices and powdered alloy core inductors enables high switching frequency and power density. A stable closed loop control allows four different power flows: PV- EV, EV-grid, grid-EV and PV-grid. Hence the converter operates as a PV inverter, a bidirectional EV charger and a combination of both. A 10kW prototype has been successfully tested and its experimental waveforms and measured efficiency are presented. It has three times the power density and higher partial and peak load efficiency when compared to existing solutions.