Practical control strategy to apply soft switching to EV power flow control system

This paper proposes a new control method to apply soft switching DC-DC converter to the control system of power flow between traction and regenerating loaded on Electric Vehicle (EV). According to the level of current setting, DC-DC converter changes operation mode between soft switching and hard switching in order to use complementary control without detecting polarity or direction of power flow. EV power flow control system becomes simple by means of soft switching method via complementary control with hard switching on boundary region between traction mode and regenerating mode. So the dynamic performance was improved by eliminating the complexity of boundary line control. The operating principle of the proposed practical control method was verified by experiment of practical EV.