Analysis of a new soft switching PWM inverter

The resonant DC link inverter is a zero voltage switching inverter. This paper proposes a new cascade resonant DC link inverter that consists of two power converter units, a rugged resonant DC link and an inverter bridge. A detailed analysis of the soft switching process in the rugged resonant DC link and the realization of pulse width modulation (PWM) control strategy in the inverter bridge are presented. The operation modes, the input and output features and the interface between the two power converter units are also discussed. The relation between characteristics and parameters of the circuit is deduced, which provides a theoretical basis for the circuit design. The analysis results show that the rugged resonant DC link can be open-loop controlled and that control of the rugged resonant DC link is independent of that of the inverter bridge, which makes inverter control easy and realizable. The inverter circuit is simulated with the electronics simulation software PSPICE. The simulation results of the circuit verify circuit analyses.