Proposal of Bilateral Buck and Boost Chopper Circuit SAZZ-1 for EV Drive Application and the Test Evaluation at 25kW

A new high efficiency and high power bilateral boost and buck chopper circuit for the electric vehicle (EV) drive application is presented. The operation principle of SAZZ (snubber assisted zero voltage and zero current transition) topology was applied and a new SAZZ bilateral buck-boost chopper circuit (SAZZ-1) was created by combining two basic SAZZ circuit types. A 50 kHz-25 kW SAZZ-1 was fabricated and tested. 96.57% efficiency at 25 kW with boost mode (input:250 V/output:390 V) in forward direction and 97.44% efficiency at 25 kW with buck mode (input:420 V/output:300 V) in forward direction were obtained. The high potentiality of SAZZ-1 chopper could be demonstrated as we expected.