An examination of radiated electromagnetic emission from hard and soft switched power converters

In recent years, several soft switching power converters have been proposed for a wide range of applications. The voltage and/or current waveforms associated with the switching phenomena in these power converters feature smooth and controlled transitions when compared to conventional hard switched power converters. It has been widely acknowledged that the radiated electromagnetic emission from soft-switched power converters are less than those from conventional hard-switched power converters. This paper is aimed at presenting a comparative study made on hard and soft switched power converters focusing on electromagnetic emission. A zero voltage soft switched power converter and a hard switched power converter which have minimal structural differences are compared in this paper using a simple first order model. This paper presents results from the study performed on hard and soft switched power converters including preliminary experimental results