A novel soft-switching inverter for high power application with simple control

A novel soft-switching inverter with regenerative snubber circuits is proposed. This inverter can be operated in soft-switching condition by simple control, without any additional complicated control. Having a passive clamp circuit, a maximum voltage across main switches is suppressed. In addition, voltage of each dc link capacitor is automatically balanced in a half of dc voltage. In this paper, soft-switching operations and other characteristics are descripted in detail. Numerical simulation and experiment with a 1.7 kVA three-phase model was conducted. Because there is undesirable voltage and current resonance due to parasitic components, measures to deal with these problems are also presented. RC snubbers were designed and applied to the experimental system to eliminate these oscillations.