Design and implementation of a passively clamped quasi resonant DC link inverter

The passively clamped quasi resonant DC link (PCQRL) inverter is a novel soft switched inverter topology proposed to solve two major problems associated with the conventional passively clamped resonant DC link inverter: the high clamp factor problem and the lack of PWM capability. This paper deals with design and control of a three phase PCQRL inverter. Major design issues are discussed. Successful operation of this novel PCQRL inverter based on a prototype design is demonstrated. The results show that this novel converter can reduce the clamp factor from the value of 2.0 p.u. obtained in previous circuits to around 1.25 and add the PWM capabilities to the conventional passive clamp resonant DC link. Several results are presented to illustrate the performance of the proposed inverter topology