Soft switching chopper with tail loss cancel circuit

This paper describes a boost chopper for the electric vehicle (EV) and fuel cell electric vehicle (FCEV) application. The authors proposed a new high power chopper with switched tail loss cancel circuit (TLC) for improving the efficiency. The proposed topology contributes a solution against tail loss increase problem when SAZZ (snubber assisted zero voltage zero current transition) topology is applied to high power range such as 100 kW. 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 high power SAZZ chopper with TLC is confirmed by simulation and experiment. TLC topology retains high efficiency of 97.9 %, comparing 97.4 % of conventional one. Total loss is reduced from 551 W (measured) to 450 W (calculated) due to the difference of the topology.