Dynamic active clamping circuit and electronic equipment

Abstract

An embodiment of the invention discloses a dynamic active clamping circuit and electronic equipment. The dynamic active clamping circuit comprises an active clamping circuit and a bypass circuit, wherein the active clamping circuit comprises transient voltage suppressors used for suppressing transient overvoltage between a collector and an emitter of an insulated gate bipolar transistor, and the bypass circuit is used for bypassing part of the transient voltage suppressors in the active clamping circuit according to drive signals. By the technical scheme in the embodiment, safer and more effective protection of operation of the insulated gate bipolar transistor is benefited.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a dynamic active clamping circuit and electronic equipment. Background technique [0002] As an important power switching device, the insulated gate bipolar transistor (IGBT, Insulated Gate Bipolar Transistor) has the advantages of both power metal oxide field effect transistors and power transistors, such as easy driving, large capacity, switching frequency advanced features. [0003] When the IGBT is turned off, the drop rate of the drain current is high, and there is a large stray inductance in the main circuit, which can cause a large surge voltage between the drain and source of the IGBT, and even exceed the rated drain-source voltage of the IGBT and cause the IGBT damage. [0004] At present, active clamping circuits are mostly used to suppress the surge voltage of IGBT turn-off. In the active clamping circuit, it is necessary to design a suitable breakdown value of the ...

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Problems solved by technology

In some applications, the grid voltage fluctuates greatly, the bus voltage will be very high, or the bus voltage will also increase when the load energy is fed back, if the set TVS diode breakdown value is too low, the bus voltage may be higher than the active embedded At this time, the active clamping circuit will malfunction and cause the IGBT to be misconducted, and the IGBTs of the upper bridge and the lower bridge will be turned on at the same time. Failure to protect in time may cause the IGBT to blow up, so there is a very large risks of

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