IGBT gate drive circuit with in-built protection and immunity to transient fault

Abstract

A new gate drive circuit for efficient switching of IGBTs has been presented in this paper. This circuit contains a short circuit protection scheme by limiting the IGBT fault current to a lower value through reduction of the IGBT gate voltage and thereby can distinguish a transient from an actual fault. Apart from the short circuit protection, the circuit also protects the IGBT in case of over-temperature. This circuit does not have any speed-up capacitor, differentiating element or latching element, thus giving good immunity towards unwanted noise. The oscillograms presented in this paper confirms satisfactory operation of this circuit.