Interrupt processing method for IGBT module driving optocoupling circuit fault signals

Abstract

The invention discloses an interrupt processing method for IGBT module driving optocoupling circuit fault signals. The method comprises the steps that a driving optocoupling circuit detects the turn-on voltage drop Vce of an IGBT module, and the low-level fault signals are output when the Vce is larger than the reference inside the driving optocoupling circuit; the fault signals are input into the interrupt input end of a microprocessing controller through a logic gate circuit and block the microprocessing controller from outputting modulation-demodulation signals through a logic circuit; the microprocessing controller compares the fault signals with sampling current of the IGBT module so as to judge whether the fault signals are interference signals or not; when the microprocessing controller determines that the fault signals are the interference signals, blockage of the logic circuit is removed, the modulation-demodulation signals are output, and the microprocessing controller quits interrupting; when the microprocessing controller determines that the fault signals are not the interference signals, the microprocessing controller sends out IGBT module short-circuit overcurrent fault information. The method avoids misinformation of the fault signals and IGBT module short-circuit overcurrent losses, and ensures normal equipment operation.

Description

technical field [0001] The invention relates to an interrupt processing method for an IGBT module driving optocoupler circuit fault signal. Background technique [0002] The IGBT module is an insulated gate bipolar transistor, which is a composite full-control voltage-driven power semiconductor device composed of a bipolar transistor and an insulated gate field effect transistor. It is widely used in the conversion system with a DC voltage of 600V and above , such as AC motors, frequency converters, switching power supplies, lighting circuits, traction drives and other fields. [0003] Usually the IGBT module is driven by the optocoupler circuit. When the IGBT module has a short-circuit overcurrent fault, the conduction voltage drop Vce of the IGBT module is detected by the saturation voltage drop detection (DESAT) function of the drive optocoupler circuit, and Vce exceeds the drive optocoupler circuit. When the internal reference is used, the fault pin of the optocoupler c...

AI Technical Summary

Problems solved by technology

However, due to the harsh electromagnetic environment of the production site, the interference signal may cause the false alarm of the fault signal of the drive optocoupler circuit, causing the malfunction of the microprocessor controller and affecting the normal control of the equipment; the existing technology can use hardware or software to detect the fault signal. Filtering, but large filtering will cause delay in protection interruption, unable to turn off the IGBT module in time, or even damage the IGBT module

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