Doubly-fed wind power generator stator current diagnosis method for impeller imbalance fault

Abstract

The invention relates to a doubly-fed wind power generator stator current diagnosis method for an impeller imbalance fault. The method concretely comprises the steps that doubly-fed generator stator single-phase current is collected, and the fundamental frequency of the stator single-phase current is extracted by utilizing FFT analysis; the fault characteristic component of the stator single-phase current under the impeller imbalance fault is calculated by utilizing the obtained fundamental frequency; an impeller rotation speed signal of a wind generation set is collected, and the characteristic frequency of the impeller imbalance fault of the stator current is calculated; spectral analysis is performed on the obtained fault characteristic component of the stator phase current by utilizing FFT, according to the fault characteristic frequency at this time, the value of amplitude at the frequency is extracted, and under the same wind speed condition, characteristic frequency amplitude values of the wind generation set under normal circumstances are compared to judge the severity of the fault. According to the method, the problem that based on an existing direct fault diagnosis method for the stator current characteristic quantity of a wind power generator, the extracted fault characteristic quantity is not obvious is effectively solved. Accordingly, the method is a fault diagnosis method capable of effectively improving the safety and reliability of blades.

Description

technical field [0001] The invention belongs to the technical field of state monitoring and fault diagnosis of wind power generators, and relates to a stator current diagnosis method of a doubly-fed wind power generator for unbalanced faults of impellers. Background technique [0002] With the increasing single-unit capacity of grid-connected wind turbines in my country, and the planning, construction and operation of large-scale wind farms, especially offshore wind farms, how to improve and ensure the operational reliability of wind turbines has become an important issue in domestic and foreign engineering and academic circles. focus of world attention. In recent years, DFIG has become one of the main models for the installation and operation of large-capacity wind farms. Research on how to apply condition monitoring technology to reduce the frequency of failures and operation and maintenance costs of DFIGs and increase their power generation has attracted attention. extens...

AI Technical Summary

Problems solved by technology

[0003] Current fault diagnosis of impellers is based on methods such as vibration, stress and strain changes of blades, temperature, X-ray imaging, and ultrasonic waves. These methods require additional sensors and data acquisition devices, which are not only costly, but also have low reliability. Very low, cannot effectively implement condition monitoring and fault diagnosis

In addition, the fault diagnosis method based on the existing wind turbine direct stator current characteristic quantity often leads to the problem that the extraction of the fault characteristic quantity is not obvious

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