Electro-magnetic doubly salient motor power converter open-circuit fault diagnosis method

Abstract

The invention discloses an electro-magnetic doubly salient motor power converter open-circuit fault diagnosis method, and relates to the technical field of fault diagnosis. According to the method, the position of a current sensor in a power converter topology is changed, a first current sensor is placed on a direct-current bus and used for detecting bus current, and a second current sensor is placed on an upper bridge arm power tube bus and used for detecting upper bridge arm power tube breakover current; in combination with the working state of the motor, the phase current is indirectly obtained through the relationship between the breakover current and the phase current of the upper bridge arm power tube to realize the normal operation of the motor; according to different current flowing paths corresponding to faults of different power tubes, fault diagnosis is realized by combining driving signals and position signals of the power tubes. Compared with a traditional fault diagnosis method without changing the positions of the current sensors, the method has the advantages that the number of the current sensors is reduced, open-circuit fault positioning of the power tube can be quickly realized, and the implementation method is simple and accurate.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis, in particular to a method for diagnosing an open-circuit fault of a power converter of an electric excitation double salient pole motor. Background technique [0002] The power converter is the weakest link in the electric excitation doubly salient motor drive system. After the power converter fails, the whole system runs in an unbalanced working state, and even causes the motor to stop. Therefore, the fault diagnosis of the power converter is an important step to improve key to system reliability. The fault types of the power converter are mainly divided into two types: short-circuit fault and open-circuit fault. A mid-series fast-acting fuse can convert this into an open circuit fault. Therefore, the open-circuit fault diagnosis of power converters is a hot research topic at present. [0003] "Research on single-tube open-circuit fault diagnosis of electrically excited doubly salient...

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Problems solved by technology

[0004] Feng Xiaobao et al. published the patent "A Power Converter and Its Method for Electrically Excited Double Salient Motors" (China, Publication Date: March 9, 2021, Publication Number: CN110138306B) which discloses a power tube in the lower bridge arm. A current sensor is placed on the top, and then the fault location is realized by pulse injection. Although this method saves costs and only needs one current sensor, this method cannot distinguish between the open circuit of the lower tube and the open circuit of the double tube, that is, there is a phenomenon of misdiagnosis. Solution fault diagnosis takes a long time

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