AN ISOLATED ZVS ZCS FLYBACK CONVERTER USING THE LEAKAGE INDUCTANCE OFTHE COUPLED-INDUCTOR/

This paper describes a simple and effective way to modify an existing hard-switched flyback converter into a circuit with zero-voltage switc hing (ZVS) and zero-current switching (ZCS). The key improvement is to turn the unattractive features of the coupled inductor leakage induct ance and snubber capacitor into attractive ones. The coupled inductor leakage inductance and snubber are used to form a quasiresonant circui t to facilitate ZVS/ZCS of all power devices. The operating principles of the converter and experimental results are presented.