Application of Time-Frequency Domain Combined Medium Response Technology in the Insulation Moisture Evaluation of Transformer Oil-Paper

Abstract

Abstract In the current period, many transformers in domestic power supply departments are in the state of overdue service, there are many problems of insulation aging and increasing water in the body, and the rapid and accurate insulation moisture assessment is a technical problem that needs to be solved. The commonly used methods of medium response test for damp evaluation of transformer oil-paper insulation system include time-domain PDC and frequency-domain FDS. These two methods have their own advantages, but also have their own disadvantages. The purpose of this paper is to transform these two test methods into time-frequency combined medium response technology combining time-domain PDC method and frequency-domain FDS method, which can be used in transformer oil paper insulation moisture evaluation to improve the efficiency of transformer operation detection. In this paper, PDC method, FDS method and time-frequency combination method were used to obtain the response curves of insulating oils with different water contents, and the curves were analyzed. By comparing the results of measuring time and water content, the effectiveness of time-frequency combination method was verified. The experimental results of this paper further show that the time-frequency domain combined media response technology has a good application value in the evaluation of transformer oil paper insulation damp.