Fault Protection Enabled Gate Drive Circuit for 3-Phase Inverter

Abstract

Asynchronous motors used in applications like electric vehicles require protection against all possible fault conditions like short circuit, over voltage, over current etc., for their reliable operation. 3-phase inverter is used as power modulator for induction motor. In this paper a novel fault protection scheme is implemented for inverter used in modulating voltage and frequency of power supply driving 3-phase Induction Motor. Function of gate drive circuits used in power electronics converters is to provide isolation for gate signals and shift the voltage level of gate pulses to the required level to enable turn on and turn off the switches as desired. Gate signals are generated using Texas instrument F28069M board. Level shifting is achieved by buffer ICs and fault protection is provided by enabling shut down pin in the DSP on occurrence of fault. Hardware results show that modulation index of gate signals is set to zero under fault conditions and ensure total safety of Inverter driver circuit and power circuit used in the Inverter.