On Inverter Circuits with Least Trapped Energy

Trapped energy in the commutation circuits has several adverse effects on the overall performance and cost of the inverter. In this paper, the influence of trapped energy on the inverter performance is thoroughly discussed. Two auxiliary impulse commutated inverters (one of current cummutation type and the other of voltage commutation type) are described and their performances are compared with those of the well-known modified McMurray (current commutation) inverter and the McMurray-Bedford (voltage commutation) inverter. Both the commutation circuits described in this paper have ideally zero trapped energy. Expressions for various parameters are derived to discuss the advantages of these inverters over the conventional inverters. The advantages of these inverters with least trapped energy in pulse width modulated (PWM) inverter applications are examined. Prototype units have been built and test results are presented.