Research on the Multiphysics Field-Circuit Coupling Model of Press Pack IGBT Considering the Application of Hybrid HVDC Breakers

Press pack insulated gate bipolar transistor (PP IGBT) is suitable for the hybrid high voltage direct current (HVdc) breaker to clear the fault current of the flexible HVdc transmission system with its advantages of double-side cooling, short-circuit failure mode, and easy to connect in series. However, it should have the ability to transmit the fault current, which is up to five or six times of its rated current, within several milliseconds depending on the distances between two stations without external cooling system. The junction temperature of PP IGBT will increase sharply and it is not possible to be measured during that situation. Therefore, the accurate prediction of junction temperature is extremely important for the packaging design of PP IGBT according to its working condition. In this article, an electro-thermo-mechanical multiphysics field-circuit coupling model of PP IGBT, which is coupled with the electrical, thermal, and mechanical fields, is proposed to predict the collector current, clamping force, and junction temperature. The 3-D mechanical model is decoupled with the 1-D electro-thermal Cauer network model to simplify this multiphysics model without reducing its accuracy. Both the normal and worst working conditions are analyzed through this multiphysics field-circuit model.