Primary fault diagnosis method of converter in wind turbine system

Abstract

The invention discloses a primary fault diagnosis method of a converter in a wind turbine system. The method includes steps of establishing a primary fault classification principle; measuring direct current side output voltage signals of the converter in states of normal operation and fault operation, subjecting the obtained output signals to wavelet packet analysis, reconstructing a wavelet packet decomposition coefficient, extracting and calculating energy of each frequency band signal, and determining which frequency range energy of an original signal mainly concentrates on; subjecting the signals in the frequency range to wavelet power spectrum analysis, and determining fault characteristic frequencies; and analyzing and comparing the characteristic frequencies and power spectrums of the converter in the states of normal operation and various fault operations to obtain a primary fault diagnosis result of the converter. By means of characteristics of wavelet packet analysis, fault diagnosis of the converter can be simply and rapidly achieved in the aspects of energy spectrums and power spectrums, and the fault diagnosis method of the converter is capable of effectively improving safety and effectiveness of the wind turbine system.

Description

technical field [0001] The invention relates to the field of wind power generation, in particular to a primary fault diagnosis method for a converter of a wind power generation system. Background technique [0002] Wind power is the fastest growing renewable energy in the world, and has become an indispensable force to solve the world's energy problems. Wind power systems are often installed in remote, inaccessible or climates that are not suitable for human long-term stay. For a long time , has been using the method of planned maintenance and after-the-fact maintenance. Scheduled maintenance is performed after 2500 hours or 5000 hours of operation, so it is impossible to fully and timely understand the status of the equipment; after-the-fact maintenance is protracted and the loss is huge. Using effective equipment monitoring and fault diagnosis methods, it is possible to continuously monitor various parameters in the operation of wind turbines, and obtain various informati...

AI Technical Summary

Problems solved by technology

In the sub-synchronous state, when the grid voltage or frequency deviates too much, it is easy to damage the IGBT components on the grid side; and in the super-synchronous state, if the fan speed is too fast, the slip power increases to exceed the rectification capacity of the rectifier , it is easy to cause damage to the IGBT components on the rotor side. When the failure of the switching tube is serious and enlarged, the motor will not work normally. Therefore, choosing an appropriate method to realize the fault diagnosis of the system is the main problem now.

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