Research on A Novel Parallel Resonant DC Link Soft Switching Inverter Based on SiC MOSFET

In order to realize a silicon carbide (SiC) MOSFET soft switching inverter with low loss, low stress and easy to design, a parallel resonant DC link (PRDCL) soft switching inverter topology is adopted in this paper. In this topology, the switches in the main inverter circuit realize zero voltage (ZV) and zero current (ZC) turn-on and -off, which is lossless; The switches in the auxiliary circuit realize quasi-ZC turn-on and quasi-ZV turn-off, which helps to significantly reduce switching losses. The topology is convenient to control without setting inductor current threshold. And it avoids using coupled inductor and split capacitor which reduce power density, and the latter will also bring neutral point potential drift. And its control is simple and the parameter design only depends on the DC power supply voltage and load/bus current peak value. In this paper, according to the commutation law of bus current, the working mode is distinguished and resonance parameters and delay time selection are introduced. At last, the 5kW/16kHz inverter prototype is made by adopting SiC MOSFET as switching device, and the soft switching characteristics are verified by experimental results.