A method and system for open-circuit fault diagnosis of a three-phase voltage source converter based on a tracking differentiator

Abstract

The application provides a three-phase voltage source converter open-circuit fault diagnosis method and system based on a tracking differentiator, first, currents of a three-phase VSC are collected, and three differential currents are obtained by using three differential trackers respectively; diagnosis of a first IGBT open-circuit fault needs to identify a zero-crossing interval; when a differential current of a certain phase is close to 0 for a period of time, it is considered that the differential current of the phase has a zero-crossing interval; after the zero-crossing interval occurs, whether the maximum and minimum values of the differential current of the phase in a period relative to the maximum and minimum values in the last period are changed is judged; according to the analysis result, a second IGBT open-circuit fault is analyzed, and the three-phase voltage source converter open-circuit fault is completed.

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