Gate Drive Circuit with Input Capacitance C_iss Measurement Function for the Condition Monitoring of Power Devices

Abstract

This paper presents an operation verification of a proposed gate drive circuit with a condition monitoring function for silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). The proposed gate drive circuit has an in-situ measurement function of the input capacitance of SiC MOSFETs to detect gate oxide degradation, which is an issue affecting the long-term reliability of SiC MOSFETs. This study demonstrates, both theoretically and experimentally, that input capacitance is an aging precursor suitable for condition monitoring. In addition, experimental verification of the gate drive at a switching frequency of 20kHz and the in-situ measurement function of the input capacitance as condition monitoring are demonstrated for a 1.2kV SiC MOSFET.