An Improved Fault Protection and Identification Driving Technology for High-voltage High-power IGBT

As core devices of power electronics equipment, insulated gate bipolar transistors (IGBTs) are widely used in various application, such as rail traction and high voltage direct current transmission. If a short-circuit fault occurs and it can’t be detected in time, the equipment will probably suffer damage, which can cause a severe accident and economic loss. This not only gives more stringent challenge to the reliability of high-power IGBT modules, but also puts forward higher requirements for the gate drivers. The IGBT generally depends on accessory drivers for protection when a short-circuit fault occurs, but now the existing detection techniques have their own shortcomings. For this reason, this paper presents the detection scheme without blank time using a combination of Vce de-saturation detection and di/dt detection, which can execute two-level turn-off and record the number of times for short-circuit faults. Firstly, the proposed detection circuit and control scheme are introduced in detail and then the feasibility and effectiveness of the proposed method have been validated by simulation results in Pspice. Afterward, two types of experiments are performed. First, the fault-detection circuit is tested by simulated short-circuit fault experiments. The results show the proposed scheme could protect IGBT under short-circuit faults such as Hard Switching Fault (HSF) and Fault Under Load (FUL) without blank time. Second, the double pulse tests are made to verify the control algorithm could decrease the false alarm rate and improve the fault identification for short-circuit faults.