Dynamic Voltage Balancing of the Series Connected IGBTs

Abstract

In the recent year, power electronics have increasing applications in high voltage power system which can be achieved by connecting lower rating power semiconductor devices in series connection to improve the power rating and voltage rating of power electronic converters. The main issue in series - connected insulated gate bipolar transistors (IGBTs) is the voltage balancing during dynamic and static states across each device. Voltage imbalance is mainly due to delay in gate drive signal, unequal leakage current of the device and mismatch in switching characteristics of the device. There are various methods for minimizing the voltage imbalance among the series connected devices in the string. Aim of this project is develop the voltage balancing circuit which will solve both static and dynamic voltage balance with simple structure, high reliability, low additional losses in the balancing circuit and number of devices can be easily connected in series.