Control of SiC-based dual active bridge in high power three phase on-board charger of EVs

Abstract

This paper presents a control algorithm of active power flow between traction battery and grid in a dual active bridge converter (DAB). Here, DAB is a part of a three phase 10kW bidirectional on-board charger in electric vehicles (EVs). It is an isolated interface to the battery placed after a three phase power factor correction (PFC) stage. 1200V rated SiC JFETs in the H-bridge at the DC link side of DAB enable operation at high voltage values of the DC link (above 500V) with high switching frequencies in the range from 50 to 150 kHz. Both high converter efficiency and simplified, compact converter design can be achieved thanks to the application of these wide band gap (WBG) devices. Furthermore, the control algorithm is presented to achieve the fast reference tracking even in the case when, due to simplicity of sensing, only average values of currents of both battery and DC link are being regulated.