Active clamp voltage stress suppression circuit of power switch, active clamp voltage stress suppression method of power switch and driving circuit of power switch

Abstract

The invention discloses an active clamp voltage stress suppression circuit of a power switch, an active clamp voltage stress suppression method of the power switch and a driving circuit of the power switch, wherein an active clamp circuit is connected between an input end and a control end of the power switch, and the suppression circuit comprises a detection module and an execution module, wherein the detection module is used for detecting whether the power switch triggers active clamp; and the execution module is arranged in a driving path of the power switch and used for cutting off the driving path when the active clamp is detected by the detection module. according to the suppression circuit and the suppression method provided by the invention, whether the power switch triggers the active clamp is detected, when the active clamp is detected by the detection module, the current driving path of the power switch is cut off, and thus, a bypass function of the driving path on current injected into the power switch by the active clamp is eliminated, utilization rate of reverse breakdown current of the active clamp circuit is improved, consequently, clamping effect of the active clamp is improved, thermal loss of TVS in the active clamp circuit is reduced and thermal loss of the driving circuit is reduced, and reliability of the active clamp circuit is improved.

Description

technical field [0001] The invention relates to the field of motor control, in particular to an active clamp voltage stress suppression circuit, method and drive circuit of a power switch. Background technique [0002] IGBT (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor) is a common power switching device, which is often used in high-voltage and high-current conditions. During the turn-off process of the IGBT, the induced electromotive force generated on the stray inductance of the loop is superimposed on the bus voltage, which causes a large voltage stress between the collector and the emitter of the IGBT. Active clamp technology detects the voltage between the collector and emitter of the IGBT through TVS (TransientVoltage Suppressor, also known as transient suppression diode). When the voltage exceeds the breakdown voltage of TVS, TVS is reversely broken down, resulting in The breakdown current flows to the gate of the IGBT, which can slow down the...

AI Technical Summary

Problems solved by technology

[0005] It can be seen from the above that due to the bypass effect of the drive circuit in the prior art, the current injected into the gate of the IGBT by TVS reverse breakdown is lost, which greatly affects the effect of active clamping and the service life of TVS

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