A zero-current-switching based three-phase PWM inverter having resonant circuits on AC-side

The authors present a zero-current-switching (ZCS)-based three-phase PWM (pulse-width-modulated) inverter having small resonant circuits on the AC side, whose resonant frequency is 50 kHz. The ZCS inverter can greatly reduce the switching losses and electromagnetic noise. The principle of ZCS operation, the design of the resonant circuits, and the control sequence are described from theoretical and practical points of view. Experimental results obtained from a ZCS PWM inverter driving an induction motor of 2.2 kW are shown to verify the practicability of this device.<>