Analysis of the IGBT/freewheeling diode switching behaviour during turn-on in hard switching applications

The aim of the work presented in this paper is to gain a better understanding of the IGBT, freewheeling diode and circuit interaction during turn-on in a hard switching inductive load application. The main factors influencing the switching speed (commutating di/dt) and the turn-on losses in both the IGBT and freewheeling diode are discussed and analysed with the aid of simulation and experimental results. This study is particularly important in order to reach to some important conclusions on the device and circuit design requirements for optimum performance. Also, it provides a more detailed insight on the device and circuit topology that allows an acceptable compromise between switching speed, power dissipation and electromagnetic radiation.