Method and device for automatically identifying defects of power transformer based on David pentagram

Abstract

The invention discloses a power transformer defect automatic identification method and device based on a David pentagram, and the method comprises the following steps: (1), judging whether the concentration and growth trend of dissolved gas in to-be-detected transformer oil are abnormal or not, determining that the detected transformer is in a normal state if the concentration and growth trend arenormal, and entering the next diagnosis step if the concentration and growth trend are abnormal; (2) calculating the respective proportions of the five characteristic gases H2, C2H6, CH4, C2H4 and C2H2, and calculating the coordinates of the geometric center point of the five characteristic gases H2, C2H6, CH4, C2H4 and C2H2; (3) determining boundaries of the eight polygonal regions according toboundary nodes defined by defect types of the David pentagon 1 and the David pentagon 2; step (4), automatically identifying an area to which the geometric center point belongs in the pentagram pentagram, and determining a main defect type; if the main defect type is a thermal defect, obtaining auxiliary defect feature description at the same time.

Description

technical field [0001] The invention relates to the technical field of electrical equipment fault diagnosis, in particular to an automatic defect identification method and device for power transformers based on David's Pentagram. Background technique [0002] In order to reduce the investment cost of power equipment outage maintenance, in recent years, power transformers have developed rapidly in non-stop maintenance, providing technical support for timely detection of latent defects and avoiding equipment failure. Among many detection methods, Dissolved Gas Analysis (DGA) method is one of the most commonly used detection methods for power transformers. Methods of analysis and diagnosis. The method can realize oil extraction for off-line gas concentration measurement during the operation of the power transformer, and also has a corresponding on-line automatic monitoring device. At present, the measurement accuracy of gas concentration based on off-line analysis of oil extr...

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Problems solved by technology

In practical application, the premise of ensuring the accuracy of the analysis results of this method needs to determine whether the analyzed sample reaches a certain concentration or growth rate, and, under the trend of more and more popular online monitoring devices for dissolved gas analysis in oil, there is still a lack of utilization of this method. Application method and device for automatic identification of power transformer defects to obtain more favorable defect characterization

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