A passive regenerative soft-switching converter with the simplest topology

The concept of the passive lossless snubber with a simpler topology is presented. A novel passive regenerative snubber, called a soft snubber, applied to a hard switching converter is proposed. It is based on a conventional L+RDC snubber but discards the loss resistor R, replacing it with an additional auxiliary winding, magnetically coupled with the main inductor of the converter. The operating principles, theoretical analyses, relevant equations, simulation studies and experimental test results of a typical PWM boost power converter equipped with the proposed soft snubber all shown. Testing was performed under conditions of different duty ratio from 0.18 to 0.65 with constant 400 V output voltage and 820 W output power at 106 kHz switching frequency.