Three phase soft switching inverter with pulse current transformer-assisted resonant snubbers

In this paper, a high frequency pulse current transformer-assisted auxiliary active resonant commutation snubber (HFTA-ARCS) for voltage source power conversion is proposed. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce the current rating of the auxiliary active power switches and simplified sensorless control scheme without the specified boost current management required for soft switching. Its operating principle and digital control scheme are described and a practical design method of circuit parameters on this HFTA-ARCS circuit is also introduced on the basis of computer simulation results. Moreover, this space vector modulated soft switching inverter system with DSP-based digital control scheme is discussed on the basis of performance evaluations. The effectiveness of this inverter is proved by simulation results and this inverter system is also compared with the conventional three-phase hard switching inverter under the conditions of specified parameters.