Closed-Loop di/dt & dv/dt Control and Dead Time Minimization of IGBTs in Bridge Leg Configuration

In order to optimize the clamped inductive load (hard) switching behavior of IGBTs in voltage source power electronic converters, i.e. to ensure a defined switching behavior independent of the load current level, the DC-link voltage or the junction temperature, in recent publications an IGBT gate drive for controlling di(C)/dt and dv(CE)/dt has been proposed and experimentally verified for chopper circuits. In this paper, the necessary modifications of the gate drive concept for applications with IGBTs in bridge leg configuration are investigated. For the purpose of a safe operation and a minimum distortion of the generated output voltage waveform, a reciprocal interlocking of the bridge leg's IGBTs is introduced in addition. Finally, the proposed concept is experimentally verified for regular operation and for different types of short circuits of the load.