Sic MOSFET short-circuit protection circuit and protection method based on comprehensive comparison of gate charge and voltage

Abstract

The invention discloses a SiC MOSFET short-circuit protection circuit and protection method for comprehensively comparing gate charge and voltage. The circuit includes a logic processing circuit, a gate charge comparison circuit, a gate voltage comparison circuit and a driving circuit; The logic signal output by the comparison circuit and the gate voltage comparison circuit judges whether a short circuit occurs in the SiC MOSFET; when a short circuit occurs, the gate voltage comparison circuit and the gate charge comparison circuit output high levels successively, and the logic circuit turns the SiC MOSFET gate Clamp to drive negative voltage, so as to realize the fast turn-off of the switch tube, and suppress the short-circuit current before the switch tube is fully turned on. The invention reduces the damage to the device caused by the short-circuit fault, does not affect the performance advantage of the high-speed switching of the SiC MOSFET, and ensures that the normal operation of the SiC MOSFET will not be affected.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a SiC MOSFET short-circuit protection circuit and a protection method for comprehensively comparing gate charge and voltage. Background technique [0002] Compared with traditional silicon (Si) devices, silicon carbide (SiC) devices have wider bandgap, higher thermal conductivity, higher critical field strength and faster saturation electron mobility, and their turn-on voltage It has the characteristics of high temperature resistance and high pressure resistance, so it has great application prospects in the fields of aerospace, hybrid electric vehicles, solar inverters, power factor correction, UPS and motor drives. [0003] However, in practical applications, on the one hand, power devices will inevitably work in abnormal working conditions such as overload and short circuit, and there is a certain delay in the protection circuit from detection to action, w...

AI Technical Summary

Problems solved by technology

[0005] Purpose of the invention: In order to solve the problems of low precision, long response time, and high cost in the prior art, we provide a SiC MOSFET short-circuit protection circuit and protection method that comprehensively compares gate charge and voltage

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