Space vector analysis and modulation issues of passively clamped quasi-resonant inverters

The passively clamped quasi-resonant inverter (PCQRL) and other quasi-resonant inverters have been shown to be not fully compatible with pulse width modulation due to a minimum dwell time created by the clamping mode in the inverter operation. This paper addresses this kind of modulation nonlinearity employing the space vector approach as a modeling tool. Closed form expressions are obtained, defining the inverter linear modulation range in terms of the dwell time and other inverter parameters, including load characteristics. Simulation results are presented to support the theoretical analysis