Fault Diagnosis Method of Current Ratio Integral Mean Difference of Switched Reluctance Motor Power Converter

Abstract

The invention belongs to the technical field of motor drive system fault diagnosis technologies, and provides a switched reluctance motor power converter current ratio integral mean value difference fault diagnosis method. The method diagnoses main switching tube open circuit and short circuit fault types of a switched reluctance motor power converter under a current hysteresis control, first a current ratio coefficient i<rn> of reference current i<ref> and phase current i<n> of each phase is calculated, then an integral average value i<rn_av> of the current ratio coefficients i<rn> of the phases in a rotor cycle is calculated, a deviation coefficient i<dn> of the integral average value of the phases is used as a diagnosis characteristic quantity, and a corresponding diagnosis characteristic quantity judgment threshold value and diagnosis rules are set, thereby realizing determination of the fault type of the power converter main switching tube. The proposed fault diagnosis method has good robustness, does not need to add an extra sensor, at the same time, an n-phase motor has n corresponding diagnosis characteristic quantities, thus diagnosis precision can be improved and occurrence of false diagnosis can be prevented, and the fault diagnosis method is suitable for fault diagnosis of power converters of different phase numbers and different topologies, and has good engineering application value.

Description

technical field [0001] The invention relates to a fault diagnosis method for the current ratio integral mean value difference fault of a switched reluctance motor power converter, especially applicable to switched reluctance motor power converters with various phase numbers, various topological structures and different power levels. Background technique [0002] The power converter is the key link in the energy conversion of the switched reluctance motor system, and its normal operation is the basis for realizing the high reliability operation of the system. Effective fault diagnosis for power converters can provide an effective guarantee for the implementation of fault-tolerant control, and accurate and reliable fault diagnosis methods can also avoid further propagation of faults, reduce system maintenance costs, and improve system operation economic benefits. Under current hysteresis control, the reference current and phase current changes are obviously different when open...

AI Technical Summary

Problems solved by technology

Under current hysteresis control, the reference current and phase current changes are obviously different when open-circuit and short-circuit faults occur in the switched reluctance motor system. At the same time, the reference current and phase current will be affected by different load torques and speeds. Therefore, it is necessary to study a fault diagnosis method that is robust to load torque and speed, simple in the diagnosis process, accurate and effective. solve the above problems

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