Dielectric response characteristic-based insulation dampness diagnosis method for transformer oil paper

Abstract

The invention relates to a dielectric response characteristic-based insulation dampness diagnosis method for transformer oil paper. The dielectric response characteristic-based insulation dampness diagnosis method comprises the following steps of: (1) selecting a transformer dielectric response curve in a transformer ex-factory temperature-rise test and three transformer dielectric response curves intersected in different temperatures in pairs; (2) calculating an amplitude with a minimal value in one transformer dielectric response curve as an original dielectric response minimal value; (3), obtaining a to-be-diagnosed dielectric response curve; (4), calculating an amplitude with the minimal value of the to-be-diagnosed dielectric response minimal value as a to-be-diagnosed dielectric response minimal value; (5), comparing the to-be-diagnosed dielectric response minimal value with the original dielectric response minimal value for judging that whether dampness is caused, if needing further confirming, entering the next step; (6), calculating three intersection points of three transformer dielectric response curves and frequencies and amplitudes of the three intersection points as original dielectric loss temperature unchangeable points; (7), obtaining three pairwise crossed to-be-diagnosed dielectric response curves; (8), calculating three intersection points of the three to-be-diagnosed dielectric response curves and frequencies and amplitudes of the three intersection points as to-be-diagnosed dielectric loss temperature unchangeable points; and (9), comparing the to-be-diagnosed dielectric loss temperature unchangeable points with the original dielectric loss temperature unchangeable points, and judging that whether paper oil insulation of a transformer is damped.

Description

technical field [0001] The invention relates to a method for diagnosing dampness of transformer oil-paper insulation, in particular to a method for diagnosing dampness of transformer oil-paper insulation based on dielectric response characteristics. Background technique [0002] At present, almost all 110kV and above transformers use oil-paper insulation, but during long-term operation, moisture will increase the water content of oil-paper insulation. Excessive water content not only affects the dielectric strength of the oil-paper insulation, but also further accelerates the aging of the insulation, reduces the mechanical and electrical life of the equipment, and affects the safe operation of the equipment. [0003] Dielectric response technology is a non-destructive diagnostic technology for detecting the water content of transformer oil-paper insulation. This technology judges the water content of transformer oil-paper insulation through the change of the dielectric respo...

AI Technical Summary

Problems solved by technology

At present, the data testing technology of dielectric response technology has become increasingly mature, but there are still problems in the data analysis technology. There are two main problems in the qualitative judgment of water content through the media response data curve: one is that the frequency range of the test data is relatively high, usually In the frequency range of 1mHz to 5kHz, the test time is long, the data test of 1mHz to 1Hz is difficult, and the field operability is poor; the second is that it is highly dependent on the test temperature, and the test curves at different temperatures cannot be compared and analyzed.

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