Fault online diagnosis method for power transformer winding

Abstract

The invention provides a fault online diagnosis method for a power transformer winding. The method comprises the steps of acquiring three-phase mechanical vibration signals at two positions of the surface of a low pressure oil tank of a power transformer by adopting a vibration signal acquisition device; performing signal source separation on the acquired three-phase mechanical vibration signals at the two positions of the power transformer by adopting a blind source separation algorithm to obtain three-phase mechanical vibration signals of the power transformer winding; performing three-layer wavelet packet decomposition reconstruction on the three-phase mechanical vibration signals of the power transformer winding by adopting a wavelet packet decomposition algorithm to obtain spectra of the mechanical vibration signals of the power transformer winding, and obtaining an energy entropy value of the mechanical vibration signals of the power transformer winding by calculation; and judging the state of the current power transformer winding according to the obtained energy entropy value of the mechanical vibration signals of the power transformer winding and the relation between an energy entropy upper limit threshold and an energy entropy lower limit threshold. The method can accurately judge the state of the current power transformer winding.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis of power transformers, and in particular relates to an online diagnosis method for winding deformation faults of power transformers. Background technique [0002] As one of the most important hubs of the power system, the power transformer's safe and reliable operation is directly related to the safety and reliability of the power generation and power supply system. Therefore, the fault detection, maintenance and repair of the transformer are important tasks to ensure the normal operation of the power supply system. . Judging from the previous fault diagnosis cases of transformers, most of the faults of transformers are not insulation problems, but mechanical performance problems leading to electrical faults. Among the mechanical performance faults, the faults caused by winding deformation account for most of the faults. Axial or radial dimensional changes that occur under the action of f...

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Problems solved by technology

However, the following problems still exist: (1) There are certain difficulties in how to accurately separate the vibration signals of the winding and iron core from the mixed vibration signals on the surface of the transformer oil tank under the grid-hung operation; (2) There is no Method of Effective Online Monitoring of Transformer Operation Status

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