Short-circuit shutoff method for insulated gate bipolar transistor (IGBT) of high-power current transformer

The invention discloses a short-circuit shutoff method for an insulated gate bipolar transistor (IGBT) of a high-power current transformer, which is applied in the fields of wind power current transformers and current transformers for ships and the like. The shutoff method for a bypass switch of the conventional short-circuit soft shutoff technique is improved, a detection circuit in a gate voltage discharge process is increased for detecting the gate voltage during discharging, and the bypass switch is actuated to enter the soft shutoff process after the preliminary discharge process of the gate voltage is finished. The method overcomes the defect of long shutoff time delay of the conventional soft shutoff technique, reduces the delay time of the conventional short-circuit soft shutoff during discharging, shortens the operating time of the soft shutoff operation, and increases the survival rate of the IGBT in the short-circuit process.