Research on the mechanism of dynamic avalanche induced by IGBT short circuit and its influencing factors

The insulated gate bipolar transistor (IGBT) is currently the most important power electronic device. It has a simple drive circuit, high operating frequency, and stable temperature. Through structural optimization and the development of new materials, its voltage and power levels have gradually increased. First, a four-unit parallel device model was established, and the electric-thermal coupling numerical simulation method was used to simulate the current, electric field, hole concentration, temperature distribution, impact ionization rate and other parameters during the dynamic avalanche process of Type II IGBT, revealing the conditions under short-circuit conditions. dynamic avalanche mechanism. On this basis, different structural parameters were compared and analyzed.