The multi-open-circuit fault diagnosis method suitable for multi-phase motor driver

Abstract

The invention discloses a multi-open-circuit fault diagnosis method suitable for a multi-phase motor driver. Fault diagnosis variables are constructed on the basis of fundamental currents and harmoniccurrents in a reference coordinate system, and auxiliary calculation such as moving average is designed by analyzing fault characteristics of the constructed variables under various open-circuit faults, so that a fault index is defined. Aiming at the characteristic value expression of a fault index under an open-circuit fault, a threshold value judgment method combining characteristic value detection and a counting method is designed. And finally, a group of fault diagnosis marks is designed, and a multi-open-circuit fault diagnosis result of the multi-phase motor driver is obtained by checking the values of the diagnosis marks and combining a fault diagnosis table. According to the invention, the open-circuit fault of multiple switching tubes of the driver can be detected; the method hasstrong robustness, and does not generate a false alarm signal even under the condition of sudden load change or sudden rotating speed change; all calculations do not involve non-linear calculations,are compatible with a low-end digital processor with low processing capability, and have low requirements on the operational capability of the processor.

Description

technical field [0001] The invention relates to the technical field of motor drive, in particular to a multiple open-circuit fault diagnosis method suitable for multi-phase motor drivers. Background technique [0002] With the continuous development of power conversion technology, the number of phases of the motor system has been further expanded from the traditional three-phase system to the multi-phase system. Compared with the three-phase system, the outstanding performance of the multi-phase system in the field of low voltage and high power makes it applied in many important occasions such as aerospace, ship propulsion, and high-speed EMU electric traction system. However, whether it is a three-phase system or a multi-phase system, there are weaknesses in power electronic products. Specifically, the damage of a certain component will cause the performance of the entire system to decline sharply or even fail to work. Therefore, fault tolerance is often an important indic...

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Problems solved by technology

Therefore, the problem of online diagnosis of multiple open circuit faults needs to be solved and optimized

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