Influence of negative voltage between gate and emitter to the turnoff behavior of IGBT device

This paper describes the dependence of turn-off switching characteristics on negative gate voltage (-VGE) for IGBT devices. Although the value of - VGE affects the turn-off switching characteristic, that has not been investigated in detail. The experimental result shows that the -VGE affects dvCE/dt and turn-off energy when the gate resistance is relatively large. Because the dvCE/dt is strongly related the discharging current of CGC. In case of the small resistance, the dvCE/dt does not change by the negative gate voltage and gate resistance, because there is a limit of dvCE/dt. In this condition, the load current can be kept only by the swept-out current.