Mechanical fault diagnosis method of gas insulated switchgear based on abnormal vibration

Abstract

The invention relates to a mechanical fault diagnosis method of a gas insulated switchgear based on abnormal vibration. The method comprises the steps of taking a vibration signal of a GIS in a normalstate as a reference, judging that a vibration signal is abnormal, and then carrying out the feature extraction; adopting the wavelet packet decomposition to process the abnormal vibration signal, obtaining the wavelet packet feature entropies of all frequency bands, and constructing the feature entropy vectors; and constructing a data set according to the feature entropy vectors, and performingfault mode identification by adopting a BP neural network. According to the invention, by utilizing the advantage that the wavelet packet energy entropy has multiple resolutions, the time-frequency localization depiction advantage is obvious, and the method is very suitable for processing the stable and non-stable vibration signals; meanwhile, by overall planning the vibration signals under the action of four excitation forces including a circuit breaker, an isolation switch, a grounding switch and an electromagnetic force, the data information is comprehensive, the diagnosis reliability is high, and a calculation result is accurate.

Description

technical field [0001] The invention belongs to the technical field of intelligent substations, in particular to a method for diagnosing mechanical faults of gas-insulated combined switchgear based on abnormal vibration. Background technique [0002] GIS equipment has been widely used all over the world since it was put into practical use in the 1960s. At present in China, the use of SF6 gas to replace insulating oil and air in high-voltage circuit breakers has become the mainstream. Newly built or renovated 220KV and above transformer stations basically all use switchgear. As of 2000, there were a total of 12,162 circuit breakers with a voltage level of 220KV and above in the country, of which 100% of the 500KV switchgear and nearly 100% of the 330KV switchgear were circuit breakers and GIS; and 220KV voltage level circuit breakers and GIS It accounts for 50% to 60% of the shipped switchgear. [0003] Despite its many advantages, GIS still has some disadvantages. For exa...

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Problems solved by technology

However, this patent does not take into account the problem of mechanical fault diagnosis under the action of other excitation sources (such as isolation switch excitation, earthing switch excitation and electromagnetic force excitation)

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