Calculation and analysis of switching losses in IGBT devices based on switching transient processes

Accurately revealing the generation mechanism and the mathematical relationship with system parameters of the power loss in the switching transients of high-voltage large power IGBT devices is very important for the device selection and circuit design of converter equipment. To reveal the mechanism of generating switching losses, this paper analyzes the switching transient processes of the IGBT devices in the basic commutation circuit in detail. Then this paper proposes an accurate calculation method based on a finite state machine (FSM) for the switching losses of IGBT devices, and verifies the correctness of this method. To further reveal the mathematical relationships among switching losses, device parameters, and loop parameters, approximate analytical formulas for the switching loss of different switching transient processes are mathematically derived, which can provide a theoretical basis for reducing the switching losses in converters.