Auxiliary resonant commutated soft-switching inverter with bidirectional active switches and voltage clamping diodes

Abstract

This paper presents a soft-switching PWM inverter with auxiliary resonant bridge-leg link snubbers on the basis of bidirectional active power switches and voltage clamping diodes. The voltage clamping diodes protect the bidirectional active switches from spike surge voltage caused by the stray energy of auxiliary inductors and parasitic wiring inductances. From a practical point of view, a variety of resonant snubber circuits with the voltage clamping diodes are also presented, Among the variations of the proposed resonant snubber circuits, emitter-emitter connected type IGBT bidirectional active switch and two clamping diodes type snubber circuit is discussed in detail. Furthermore, the performances of the proposed soft switching PWM inverter with the auxiliary resonant bridge-leg link snubber-associated inverter-fed DC to DC converter is demonstrated and evaluated in order to prove feasibility applying for an X-ray high-power high-voltage application.