Investigation of voltage stress on a single switch boost-fly-back integrated high gain converter with light load condition

Abstract

In this paper, investigation of voltage stress on a single switch Boost-Fly-back integrated (SSBFI) DC-DC converter is carried out for light load condition. During this condition, reverse recovery occurs on the switches of the converter enabling resonance condition on the parasitic elements of the devices causing an increased device voltage stress. An appropriate snubber parameter design is a prerequisite to save the devices from the affect of such stress. A proper snubber design can be achieved with a detailed realization of the parasitic elements and suitably evaluated through a complex and tedious analysis. However, an indirect method using maximum voltage stress analysis can also be a suitable alternative for proper snubber design. A detailed study is carried out in this regard mainly focusing on power electronic device voltage stress in steady state under variation of load condition. The theoretical analysis is validated through a laboratory prototype with a capacity of 50 W. Keywords: Coupled inductor, Gain cross over, Light load condition, Single switch, Voltage stress on devices