Method and device for acquiring inherent frequency band of post insulator

Abstract

The embodiment of the invention discloses a method and device for obtaining the inherent frequency band of a post insulator. The method comprises: according to a preset sampling frequency, acquiring avibration signal of a normal post insulator; carrying out wavelet packet decomposition on the vibration signal; and acquiring a multi-layer wavelet tree, acquiring each node frequency band of the last layer wavelet tree according to the sampling frequency, acquiring an energy ratio of each node frequency band, further acquiring an average energy ratio value of each node frequency band of a plurality of normal post insulators, and acquiring an inherent frequency band according to the average energy ratio value of each node frequency band. Since the inherent frequency band is the frequency bandrange acquired for a plurality of normal post insulators, whether the post insulators have defects or not can be judged through the inherent frequency band acquired by the invention, and the accuracyof a judgment result can be improved.

Description

technical field [0001] The present application relates to the technical field of power equipment fault monitoring, and in particular to a method and device for obtaining a natural frequency band of a post insulator. Background technique [0002] Post insulators are often used for structural support and insulation of electrical equipment. If post insulators are subjected to cyclic thermal stress, mechanical shock and environmental erosion for a long time during operation, various defects may occur. When the post insulator has defects such as cement degumming and porcelain cracks, its natural frequency will change. At present, the vibro-acoustic detection method is generally used to obtain the natural frequency of the tested post insulator, and then compare it with the natural frequency of the normal post insulator to determine whether the tested post insulator has defects. [0003] However, in the production process of different post insulators, affected by various factors s...

AI Technical Summary

Problems solved by technology

[0003] However, in the production process of different post insulators, affected by various factors such as manufacturing process, manufacturing materials, and shapes, there are more or less differences in their natural frequencies. Even if both are normal post insulators, their The natural frequency may also be different, so when judging whether the tested post insulator is defective, the natural frequency of the normal post insulator is used as the only criterion, and the judgment result will have certain errors

Images