Method for on-line monitoring of mechanical fault of on-load tap-changer of transformer

Abstract

The invention discloses a method for on-line monitoring of a mechanical fault of an on-load tap-changer of a transformer. The method comprises the following steps of attaching three vibration sensorsto the top end of a box wall of the on-load tap-changer, and collecting a vibration signal generated in an action process of the on-load tap-changer; carrying out empirical mode decomposition (EMD) onthe collected signal, and computing an improved mask signal through a decomposed intrinsic mode function (IMF); adding the improved mask signal to the original collected vibration signal, and then carrying out empirical mode decomposition; and computing a power characteristic matrix of the intrinsic mode function according to an interval maximum power characteristic formula, comparing the power characteristic matrixes of the OLTC under different working conditions, and carrying out fault diagnosis on the OLTC. According to the method, a working state of the on-load tap-changer of the transformer can be monitored in real time, and the requirement for real-time fault diagnosis of the on-load tap-changer of the transformer can be met. A data support and a theoretical basis are provided for purposeful overhauling, and the waste of manpower, material resources and time is avoided.

Description

technical field [0001] The invention belongs to a signal monitoring method for electric equipment, in particular to an online monitoring method for a mechanical failure of a transformer on-load tap changer. Background technique [0002] On-load tap-changer (OLTC) is an important part of power transformer, and its operating status is directly related to the stability and safety of the transformer and 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 the statistics in the ditch, the accidents caused by OLTC faults account for about 28% of the total accidents of transformers, 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 transformer itself,...

AI Technical Summary

Problems solved by technology

[0003] In the past, people did not know enough about the typical faults of tap-changers. This is mainly because the number of tap-changer actions in the past was very small, and the failure rate was relatively low. Therefore, the research was not deep enough. and achieved important research results, but there are still many problems to be solved

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