Patent ID: 10505536

Abstract:
A plurality of gate driver units (3,4) respectively drives a plurality of semiconductor switching devices (SW1,SW2) connected in parallel. A control circuit (5) controls the plurality of gate driver units (3,4). Each gate driver unit (3,4) includes a gate driver (6) supplying a gate voltage to a gate of the corresponding semiconductor switching device (SW1,SW2), and a potential difference measuring unit (7) measuring a potential difference (Va) arising due to wiring inductance on an emitter side of the corresponding semiconductor switching device (SW1,SW2) for each cycle of an output frequency. The control circuit (5) adjusts the gate voltage (VGE) supplied by the gate driver (6) of each gate driver unit (3,4) such that the potential differences (Va) of the plurality of semiconductor switching devices (SW1,SW2) in turn-on or turn-off switching operation become same as each other.