SiC MOSFET grid crosstalk suppression circuit and drive circuit

Abstract

The invention discloses an SiC MOSFET grid crosstalk suppression circuit and a drive circuit. The grid crosstalk suppression circuit is connected between a grid and a source of the SiC MOSFET and theSiC MOSFET drive circuit on the basis of a bridge type converter, and comprises a triode-based negative voltage ripple suppression circuit and an MOS transistor-based straight-through preventing circuit; the voltage ripple suppression circuit is used for suppressing negative voltage between the grid and the source of the SiC MOSFET, and the straight-through preventing circuit is used for preventing mutual straight through between bridge arms of the bridge type converter.

Description

technical field [0001] The invention relates to the technical field of power electronics drive, in particular to a gate crosstalk suppression circuit of SiC MOSFET and its drive circuit. Background technique [0002] With the continuous development of power electronics technology, many fields such as electric vehicles and oil drilling have put forward higher requirements for power electronic converters, which need to be able to work reliably in high temperature environments. The new SiC power device has good characteristics such as large band gap, high breakdown voltage and high thermal conductivity, which provides the possibility for the design of high-temperature power electronic converters. In addition, due to the inherent characteristics of SiC MOSFET, the design of its driving circuit is different from that of Si material MOSFET, mainly in the following aspects: on the one hand, in order to increase the switching frequency of the device and reduce the off time, the desi...

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Problems solved by technology

[0003] The bridge arm circuit is the basic unit of all kinds of bridge power electronic converters. If the design of the driving and protection circuits is unreasonable, it is easy to cause a shoot-through fault, which will cause additional power loss of the switching tube, and even damage the device in severe cases, making the circuit unable to operate. normal work

In the fast switching transient, the interaction between high dv / dt (voltage change rate) and the parasitic parameters of the device will cause the gate-source voltage to oscillate, that is, the crosstalk problem, which will easily lead to the wrong turn-on of the device and the occurrence of the bridge arm through fault

[0004] At present, most of the driving circuit designs are based on the original Si MOSFET driving circuit by adding a negative voltage power supply, but the influence of the crosstalk of the half-bridge circuit on the driving signal is not considered, resulting in gate-source negative voltage spikes exceeding the capabilities of SiC MOSFETs. Negative pressure range

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