Gate voltage pattern analyze for short-circuit protection in IGBT inverters

For the motor drive applications, short circuit protection is necessary to guarantee safety of all motor drive systems. This paper presents a new scheme for short circuit protection of IGBT by the gate voltage pattern analyzer (GVPA), which operates under the fault conditions such as hard switching fault (HSF) and fault under load (FUL). It has some functions such as short circuit detection through pattern recognition of IGBT gate voltage, gate voltage clamping for the reduction of short circuit current and soft off for the reduction of surge voltage. Moreover, it can be used to be integrated as one gate drive integrated circuit (IC) or high volatge integrated circuit (HVIC) because GVPA supplements logic and low voltage components. This paper provides simulated and actual experimental result of a new scheme under fault conditions.