Method for diagnosing severity degree of transformer fault

Abstract

The invention relates to a method for diagnosing the severity degree of a transformer fault. The method comprises analyzing the gas content in transformer oil by using chromatography; accumulating the dissolved gas content in the transformer oil tested over a certain period; calculating the nitrogen or total hydrocarbon absolute aerogenesis rate and the change rate of the aerogenesis rate; and drawing a diagram, in which the absolute aerogenesis rate is the vertical coordinate and the time is the horizontal coordinate; and judging whether a fault occurs to the interior of a transformer according to the absolute aerogenesis rate and the change rate of the aerogenesis rate. According to the method, the development and the severity degree of the fault in the interior of the transformer are judged by calculating the absolute aerogenesis rate and the change rate of the aerogenesis rate in a mode of diagram; a corresponding transformer monitoring and maintenance strategy is made; the accurate master of the operation and the interior fault situation of the transformer is achieved; the security operation of the transformer in a power grid is guaranteed; and the accident that the transformer is damaged is prevented.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis and analysis of electrical equipment, and relates to a diagnostic method for the severity of transformer faults, in particular to a diagnostic method for judging the severity of faults through chromatographic analysis of changes in dissolved gas in transformer oil. Background technique [0002] The analysis of dissolved gas in transformer oil is the most effective method for domestic and foreign power systems to monitor the operation of transformers under live conditions. At present, the power industry generally uses chromatography to regularly detect transformer oil to judge whether there is a fault in the transformer. After years of development, there has been a set of methods for judging the type of faults based on oil chromatographic analysis results. The method uses the ratio of various chromatographic data to determine the specific fault type of the transformer, and uses the absolute...

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Problems solved by technology

However, this method has limitations. In some cases, the gas production rate calculated based on the transformer oil chromatographic detection data is very large, but the actual gas production rate is in a decreasing trend. In this case, the transformer may not exist. Internal faults, only based on the absolute value of the gas production rate to judge the fault of the transformer will lead to misjudgment

On the contrary, the absolute value of the gas production rate is small and does not exceed the gas production rate limit specified in the standard, but the gas production rate increases rapidly, and there may be serious faults. If careful analysis and attention are not carried out, the best maintenance period will be delayed , and cause serious consequences of transformer damage, therefore, a more accurate method for judging the degree of transformer fault is needed

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