Oiled paper insulation power equipment insulation aging state detecting method

Abstract

The invention discloses an oiled paper insulation power equipment insulation aging state detecting method. The method includes a first step of carrying out the preparatory work, enabling oiled paper insulation power equipment to be disconnected with a line, enabling insulation terminals to be detected to be connected in a pup joint mode through copper bare wires and connected to the ground to discharge, a second step of wiring according to introductions of an instrument, a third step of setting parameters, a fourth step of finishing a detection, and obtaining a time domain feature parameter t through spectrum unfolding, a fifth step of bringing the time domain feature parameter t and oiled paper insulation temperature T to a designated formula, and calculating and judging the insulating aging state of oiled paper, that is, a degree of polymerization (DP) value, and a sixth step of confirming that the overall insulation of the oiled paper insulation power equipment is in a medium term of the service life when the average DP of the oiled paper decreases to 500, confirming expiration of service life of the oiled paper insulation power equipment when the average DP decreases to 250, and confirming that the mechanical strength of insulation paper is almost zero when the DP decreases to 150. The oiled paper insulation power equipment insulation aging state detecting method does no hang a core, does not damage insulation materials, does not carry out sampling, can accurately estimate the average DP value of the insulation paper, and judges the oiled paper insulation aging state.

Description

technical field [0001] The invention belongs to the field of insulation state diagnosis and life evaluation of oil-paper insulated power equipment, and relates to a method for evaluating the insulation aging state of oil-paper insulated power equipment based on polarization and depolarization currents. Background technique [0002] Oil-paper composite insulation is an important and excellent insulation combination method, which has been successfully used in large transformers, bushings, transformers, capacitors, cables and other power equipment. During the operation of oil-paper insulated power equipment, its oil-paper insulation is subjected to various external stresses such as heat, electricity, machinery, and chemistry for a long time, which leads to a gradual decline in its own insulation and mechanical properties and may cause failure. Therefore, accurate diagnosis of the aging state of the oil-paper insulation system is very important to predict the life of oil-paper i...

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Problems solved by technology

[0006] In order to solve the existing oil-paper insulation power equipment insulation aging state evaluation method, the transformer needs to be core-hanging to extract the insulation paper sample. The operation procedure is complicated and may damage the insulation of the transformer, and when the insulation paper sample is selected in different areas, it will lead to aging evaluation. The problem of error, the present invention provides a method for detecting the insulation aging state of oil-paper insulated power equipment

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