Design and Implementation of a Quasi-Resonant DC Link Converter

In this paper, a passively clamped quasi-resonant DC link converter is analysed, implemented and evaluated in a battery charger application. Design expressions for selection of passive component values, based mainly on the specified maximum output voltage derivative and the duration of the zero voltage interval, are given. Design of the inductive components and selection of appropriate power semiconductors for the quasi-resonant DC link are investigated. The main problems regarding power electronic design of these components are also discussed. The quasi-resonant DC link waveforms are measured and the converter efficiency is measured and compared to a hard switched case