An IGBT overcurrent detection device and method based on an active clamp feedback type

Abstract

The invention provides an IGBT overcurrent detection method based on the active clamp feedback type. The method comprises the steps that the IGBT is disconnected and the voltage peak appears when overcurrent appears in the IGBT, and the active clamp circuit works to clamp the IGBT on the protection voltage when the voltage of the two ends of the IGBT exceeds the breakdown voltage of the active clamp diode; the detection circuit effectively extracts the time of TVS branch current flowing or the time of the clamp voltage in case of active clamp actuation and transmits the time signal to the processor circuit; the processor performs statistics of the time and the frequency of the signal transmitted by the detection circuit; and the judgment result indicates the overcurrent fault of the IGBT when the time signal of TVS branch current flowing or the time signal of the clamp voltage received by the processor circuit exceeds the system setting time. The invention also provides an IGBT overcurrent detection device based on the active clamp feedback type.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to an active clamp feedback type IGBT overcurrent detection device and method. Background technique [0002] Insulated Gate Bipolar Transistor (Insulated Gate Bipolar Transistor) IGBT is widely used in power electronic circuit devices. In high-voltage and high-power applications, IGBTs often bear relatively large currents, and IGBT overcurrent is an important cause of IGBT device damage. In practical applications, due to load overload, external interference, internal signal errors and other reasons, the current of the IGBT device will increase sharply and exceed its capacity limit. At this time, the IGBT device needs to be turned off for protection to prevent the IGBT from being damaged by overheating. [0003] At present, there are three main methods for overcurrent detection of IGBT devices: [0004] 1. Desaturation detection method: by means of the relatio...

AI Technical Summary

Problems solved by technology

It is frequently broken down in a short period of time, and it also faces the problem of heat loss, which affects the reliability of the system

Although the third method can detect the system overcurrent, it cannot identify the overcurrent path, which is not convenient for fault analysis

In addition, because the current sensor in method three is installed on the load side, it is generally detected by software, and there will be a certain delay in the detection time.

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