Analysis and implementation of a three-phase soft-switching inverter

The system analysis and circuit implementation of a reduced parts three-phase soft-switching inverter (THSSI) comprising four main switches and four auxiliary switches is proposed in this paper. All main switches in the proposed THSSI operate at zero-voltage-switching (ZVS) turn-on, while the auxiliary switches operate at zero-current-switching (ZCS) turn-on and turn-off. Since the control circuits and the auxiliary circuits are thereby reduced to two sets, the reduction in the number of main switches can also increase the reliability. Thus, the proposed power converter configuration achieves fewer switching components and higher efficiency. Additionally, the dedicated control circuit required for soft-switching inverter operation is implemented using a FPGA circuit, reducing overall system cost and complexity. Some experimental results for a 500 W prototype are provided to demonstrate the theoretical analysis and system performance.