IGBT active clamping protection circuit

Abstract

The invention discloses an IGBT active clamping protection circuit, and the circuit is a part of an IGBT drive protection circuit. The circuit comprises an IGBT (insulated gate bipolar transistor) and a push pole connected with a gate pole of the IGBT. The circuit also comprises a capacitor clamping circuit, a dynamic feedback circuit, and a static feedback circuit, and a collector electrode of the IGBT is connected with the positive electrode of a DC bus. The dynamic feedback circuit mainly consists of a first transient voltage inhibition diode, a feedback capacitor, and a first diode, and the static feedback circuit is connected between an output end of a clamping capacitor and the gate pole of the IGBT. The circuit guarantees that a switching-off voltage peak value of the IGBT is less than a maximum allowable value of an collector electrode during overcurrent switching-off and short-circuit protection. The circuit not only can accurately clamp an overvoltage, but also can guarantee the dynamic and static balance of voltage of an active circuit, is smaller in loss, is high in response speed, is simple in structure, is high in reliability, and can be used for the design of an IGBT drive protection circuit under various working conditions.

Description

technical field [0001] The invention relates to a cascaded high-voltage frequency converter, in particular to an IGBT active clamp protection circuit of the cascaded high-voltage frequency converter, which belongs to the technical field of power electronics. Background technique [0002] Insulated gate bipolar transistor (IGBT) combines the advantages of power transistor (GTR) and power field effect transistor (MOSFET), and has the characteristics of easy driving, large peak current capacity, self-shutoff, and high switching frequency. Widely used in high voltage and high power occasions. [0003] The on-off protection of IGBT is a very important point in the application design of high-voltage inverters. In high-power applications such as high-voltage inverters, there is a large stray inductance (tens to hundreds of nH) in the main circuit (between the DC capacitor and the IGBT module). When the IGBT is turned off, the drop rate of the collector current is high, that is, t...

AI Technical Summary

Problems solved by technology

However, the loss of the TVS tube in this circuit is still very large, and the driving stage has a large time delay, which may cause the collector potential to not be clamped in time, the circuit effect is not very ideal, and the working point of the active clamp circuit is still not enough optimization

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