Modelling and Control of a 50kW SiC-based Isolated DAB Converter for Off-Board Chargers of Electric Vehicles

The paper proposes the design of a 50kW isolated DC-DC Dual Active Bridge (DAB) converter for a high-power off-board charger for Electric vehicles (EVs) applications. The detailed electro-thermal simulation of the wide band gap (WBG) (i.e., SiC MOSFETs)-based bidirectional DAB is performed to determine the performance of the system in terms of efficiency at high-power operation. A linear model based on system identification has been created to design the control approach accurately. Dual-loop phase shift constant-current (CC) and constant-voltage (CV) control strategy is implemented on the dynamic simulation model at a higher switching frequency to validate the stability of the designed controller. The proposed DAB operates with an acceptable ripple and dual-loop voltage-current control that comprehensively tracks reference commands, while the maximum efficiency achieved is approximately 97.5% at rated power.