Three‐phase Inverter with Compound Active‐clamping Circuit

This chapter introduces a zero voltage switching (ZVS) three‐phase inverter with compound active‐clamping (CAC) circuit, including the operation principle, the circuit analysis, and the design guidelines. Based on circuit stage analysis, it aims to derive soft‐switching conditions. The chapter presents the implementation of ZVS‐space vector modulation in practical application with digital controller such as the Texas Instruments digital signal processors. The resonant parameters in soft‐switching silicon‐carbide inverter include resonant inductor L_r, resonant capacitor C_r for each three‐phase main switch, and resonant capacitor C₇ for auxiliary switch. CAC inverter can realize ZVS operation for all switching devices and suppress the antiparallel diode reverse recovery of all switching devices. The chapter provides a design example based on a 30 kW prototype. A 30 kW ZVS inverter prototype was built to verify the designed parameters and the proposed modulation scheme.