PWM plus phase shift control strategy for dual-active-bridge DC-DC converter in electric vehicle charging/discharging system

The dual-active-bridge(DAB) converter is ideally suited for high-power dc-dc convertion, especially in electric vehicles charging/discharging system. However, it has the drawback of high circulating currents at light load. This paper analyzes the pulse width modulation plus phase shift(PWMPS) for DAB in whole operation range and proposed a new reactive power-optimized control mode. The PWMPS has two degree of freedom to control the transferring power, which can improve the performance of the DAB converter than conventional modulation strategy (CMS). The experimental results show that the proposed method can enhance the overall efficiency.