Method based on improved HHT algorithm and applied to time-frequency analysis of GIS (Gas Insulated Switchgear) mechanical vibration signals

Abstract

The invention discloses a method based on an improved HHT algorithm and applied to time-frequency analysis of GIS (Gas Insulated Switchgear) mechanical vibration signals. The method comprises the following steps: measuring GIS normal operation vibration signals and GIS vibration signals under faults, extracting characteristic quantities of the vibration signals by using ensemble empirical mode decomposition (EEMD), and carrying out hilbert transformation (HT) on the signals obtained by EEMD preprocessing to carry out time-frequency analysis on the GIS mechanical vibration signals. Through the method, the GIS vibration signals can be effectively processed by carrying out time-frequency analysis of the GIS mechanical vibration signals through adoption of a method of carrying out HT after preprocessing via an EEMD algorithm, so that a GIS mechanical fault diagnosis database is established; the theoretical basis is provided for achieving on-site live detection of the GIS mechanical faults.

Description

technical field [0001] The invention relates to a time-frequency analysis method for GIS mechanical vibration signals based on an improved HHT algorithm. Background technique [0002] Gas-insulated metal-enclosed switchgear (Gas Insulated Switchgear, GIS) will produce a variety of mechanical defects, such as loose screws, failure of the circuit breaker operating mechanism, and vibration of the transformer. Therefore, it is possible to improve the operational stability of GIS by diagnosing early defects in GIS by monitoring mechanical faults. The vibration signal generated by the internal failure of GIS is transmitted to the GIS cylinder through the medium. For the GIS equipment in operation, sensors are often placed on the surface of the cylinder to receive the transmitted vibration signal, so as to detect whether the GIS is operating abnormally, that is, a failure occurs. Because the vibration signal detection method has strong anti-interference ability and can complement ...

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Problems solved by technology

[0003] However, at this stage, the fault research on GIS is still mostly focused on the direction of partial discharge, and the vibration signals collected are mostly electromagnetic wave signals with high frequency. There are few researches on the wider and lower frequency mechanical fault signals.

Due to the complexity of the GIS structure, there is less research on the vibration characteristics of the GIS in the field. Although there are literatures in the prior art that have measured the vibration signals of the GIS in operation, the data acquisition is difficult and the data volume is limited. Analyze specific GIS failure problems

Or perform multiple detection and processing on normal and abnormal HGIS vibration signals, and obtain a correlation diagram of the corresponding vibration amplitude and frequency with respect to frequency from a statistical point of view, but does not indicate the fault problem

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