Switching tube open-circuit fault diagnosis method of open winding electrically-driven conversion system

Abstract

The invention discloses a switching tube open-circuit fault diagnosis method of an open winding electrically-driven conversion system, applied to a twin inverter-open winding motor system. The methodcomprises the following steps: step 1, monitoring a value of sum d of three-phase current per unit average values in real time, wherein d=Da+Db+Dc, and the formula is represented in the specification,wherein <> refers to solving the current average value in a single fundamental wave period, Ia, Ib and Ic are three-phase stator current; step 2, comparing the value of the sum d of the three-phase current per unit average values with a threshold value k, if d is greater than -k and less than k, an fault is not existent, if d is greater than k, the switching tube eta 12 or the switching tube eta21 has an open-circuit fault, and if the -k is greater than the d, the switching tube eta 11 or the switching tube eta 22 has the open-circuit fault, wherein eta=a, b, c. With the method provided by the technical scheme of the invention, aiming at an open winding motor-common DC bus twin inverter system, compared with the prior art, the method has the following advantages: having no need of mounting additional hardware, being capable of accurately identifying location of a fault switch under a situation where any switching tube is open-circuit, and consequently providing strong guarantee for implementation of redundancy control.

Description

technical field [0001] The invention relates to the field of open-winding motor drive, in particular to a fault diagnosis method for an open-winding electric drive system. Background technique [0002] Circuit fault diagnosis is the premise of fault-tolerant control algorithm. In general, fault diagnosis methods can be divided into model-free fault diagnosis methods and object model-based fault diagnosis methods. The former runs machine learning, artificial neural network, fuzzy logic and other artificial intelligence technologies to develop expert systems to diagnose faults, which requires large data processing and complex calculations, and is difficult to implement in engineering. The latter extracts fault features or residuals according to the analytical model of the object, and then implements fault diagnosis, which has strong engineering realization. Signal analysis, as a typical model-based diagnostic scheme, has received more research in recent years. Among them, t...

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Problems solved by technology

[0006] To sum up, none of the existing technologies can realize the switch tube fault diagnosis of the open-w

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