A comparative study of switching losses of IGBTs under hard-switching, zero-voltage-switching and zero-current-switching

A high power IGBT tester, based on the typical clamped inductive load circuit and incorporating zero-voltage-transition and zero-current-transition soft-switching schemes, has been developed. Both turn-on losses, including the losses associated with reverse recovery of the clamp (free-wheeling) diode, and turn-off losses are measured and compared for slow and fast IGBT devices. Benefits of zero-voltage-switching (ZVS) and zero-current-switching (ZCS) operation of IGBTs are demonstrated. The ZVS operation can reduce the total switching losses by more than half, while the ZCS reduces them by about 25% when compared with hard-switching. The ZCS turn-off also relieves the voltage stress of the IGBTs.<>