Method for measuring oiled paper insulated micro water content on basis of dielectric response

Abstract

The invention discloses a method for measuring oiled paper insulated micro water content on the basis of dielectric response, which fully utilizes the inherent characteristic that the dielectric constant of an insulating material changes along with voltage frequency change, and obtains the complex dielectric constant Epsilon * of a sample by measuring the relevant characteristic parameters of the output voltage gain M and the phase difference of samples with different temperatures and different micro water contents and carrying out mathematical calculation by combining with an equivalent circuit of a tester. An interactional rule between an oiled paper micro water content m and the complex dielectric constant Epsilon * and between temperature T and applied voltage frequency f is analyzed, the variation rule of tested data is fitted by a mathematical software tool to finally obtain the general function relational expression between the oil paper micro water content m and the complex dielectric constant Epsilon * and between the temperature T and the applied voltage frequency f, and finally, the function relational expression is utilized to calculate the insulated micro water content of the unknown oiled paper.

Description

technical field [0001] The invention relates to a method for measuring the moisture content of oil-paper insulation based on dielectric response, and belongs to the field of insulation state evaluation and life prediction of electric equipment. Background technique [0002] The safe operation of power equipment is the first defense system to avoid major accidents in the power grid, and the power transformer is the key equipment in this defense system. At present, the most widely used power transformer is oil-immersed transformer, and its oil-paper insulation performance directly affects the electrical performance and operating life of the transformer. Moisture is an important factor affecting the insulation performance of insulating oil and insulating paper. A small amount of moisture in the insulating oil will reduce the breakdown voltage of the insulation system and increase the dielectric loss of the insulation system. When the moisture content in the insulating oil exce...

AI Technical Summary

Problems solved by technology

However, the micro-water content in the insulating cardboard cannot be directly measured, and the information on the micro-water content in the insulating cardboard can only be obtained by means of the corresponding relationship between the micro-water in the transformer insulating oil and the micro-water in the insulating cardboard

These traditional oil-paper insulation micro-water testing methods are limited to a single piece of information, and provide very little insulation information, including only micro-water content information, and suffer from many on-site interference factors, making it impossible to establish a corresponding relationship between transformer insulation status and test results limitations

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