Investigating The Dynamic Performance Of Power Devices In Parallel Connection

With the emergence of wind power, smart grids, electric vehicles and high-voltage inverters, high-power devices have become increasingly popular in industry. The efficiency and reliability of power devices in the design of high-power systems are critical, with the efficiency and reliability of high-power switching devices playing an essential role. Thus, before designing a converter, the switching transient of the semiconductor device must be analysed using a simulation tool, typically utilising physical, behavioral, or analytical models. In this thesis, an analytical model of devices in parallel connection was proposed as a method of understanding the working principle of the internal devices of the module and simulating the current sharing behavior, with the impact of device and circuit mismatch on current sharing behavior of SiC MOSFET in parallel connection being investigated. Additionally, analytical models were applied to SiC/Si hybrid switches, combining the advantages of Si IGBT and SiC MOSFET, examining the static, dynamic, and crosstalk behavior of hybrid switches and determining the relationship between switching loss and delay time. A double pulse test platform was established to verify the model, the model showcasing good agreement with the experimental while maintaining a high simulation speed.