An OLTC fault diagnosis method based on a recursive graph and recursive quantitative analysis

Abstract

The invention discloses an OLTC fault diagnosis method based on recurrence plot and recurrence quantitative analysis, and the method comprises the steps: 1, enabling a vibration detection probe to beattached to the top end of the box wall of an on-load tap-changer, and collecting vibration signals generated in the action process of the on-load tap-changer in different states, such as normal state, contact looseness, contact abrasion, contact burnout and the like; 2, performing phase space reconstruction on the vibration signal from the recursion characteristic of the vibration signal; 3, carrying out qualitative and quantitative analysis on the phase trajectory by respectively adopting a recursive graph (RP) and a recursive quantitative analysis (RQA); And 4, carrying out fault diagnosisaccording to qualitative and quantitative analysis results. The working state of the transformer on-load tap-changer can be monitored in real time, and the requirement for real-time fault diagnosis ofthe transformer on-load tap-changer is met. Data support and theoretical basis are provided for targeted maintenance, and manpower, material resources and time are prevented from being wasted.

Description

technical field [0001] The invention relates to an OLTC fault diagnosis method based on a recursive graph and recursive quantitative analysis, and belongs to the technical field of power equipment signal monitoring. Background technique [0002] The on-load tap changer (OLTC) is an important part of the power transformer, and its operating status is directly related to the stability and safety of the transformer and the system. OLTC is one of the components with the highest failure rate in transformers. Its failure not only directly affects the operation of the transformer, but also affects the quality and operation of the power grid. According to statistics in the ditch, the accidents caused by OLTC faults account for about 28% of the total transformer accidents, and the fault types are basically mechanical faults, such as loose contacts, falling off contacts, mechanism jamming, slipping, and refusal to move. Mechanical failure will directly damage the OLTC and the transf...

AI Technical Summary

Problems solved by technology

The power outage maintenance period of on-load tap-changers is often long, and it is difficult to detect early mechanical failures in time. Failures and damages often occur before power outage maintenance, and power outage maintenance affects the normal operation of the transformer, which requires a lot of manpower, material and financial resources

[0004] On-line monitoring methods mainly include thermal noise-based diagnosis method and vibration-based on-line monitoring, etc. The thermal noise-based diagnosis is that the thermal noise generated by the heat generated after the transformer tap-changer breaks down spreads to the outside of the transformer, and is detected by installing a noise sensor on the transformer shell. To diagnose the fault of the tap changer, but when the thermal noise is transmitted to the sensor, the energy loss is too large, and various noises interfere with the engineering application, which is difficult to realize

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