Mid-power SAZZ chopper with switched tail loss cancel circuit

This paper describes a study improving mid-power snubber assisted zero voltage zero current transition (SAZZ) chopper by switched tail loss cancel circuit (TLC) for the electric vehicle (EV) and fuel cell electric vehicle (FCEV) application. The proposed topology offers a solution against tail loss increase problem when SAZZ soft switching topology is applied to mid-power range chopper design. Discharge current formed in closed switched resonant circuit by means of proposed switched tail loss cancel circuit cancels main collector current through main switch (including tail current). In this paper the performance of mid-power SAZZ chopper with TLC is confirmed by simulation and experiment. Experimental setup was fabricated. Circuitry operational test and total loss breakdown measurement through 15 kW rating test have been completed. TLC topology retains high efficiency of 97.3 % under the frequency of 30 kHz at 15 kW.