Soft-switched inverter for electric vehicle drives

A new type of soft-switched inverter which has particular potential for battery powered applications such as electric vehicle drives is proposed. The topology is derived from the passively clamped quasi resonant link (PCQRL) circuit. By introducing magnetic coupling between the two resonant inductors, the auxiliary switches can be reduced from two to one and only a single magnetic core is required for the resonant DC link. An analysis of this novel PCQRL topology with coupled inductors is presented to reveal the various soft switching characteristics. In comparison with the conventional passively clamped continuously resonant DC link inverter, this novel soft switched inverter can reduce voltage stresses from more than 2 p.u. to 1.1-1.3 p.u. It can also provide soft-switched PWM operation. Simulation and experiment are performed to backup the analysis