Method for diagnosing internal fault of oil-immersed transformer through content ratios of dissolved gases

摘要

A method for accurately diagnosing an internal fault of an oil-immersed transformer by analyzing content ratios of dissolved gases generated when the internal fault occurs in the oil-immersed transformer is provided. The method diagnoses the internal fault by analyzing the dissolved gases contained in the insulating oil of the oil-immersed transformer for internal fault diagnosis, wherein the method comprises: a first step of extracting H2, CH4, C2H4, and C2H2 from the dissolved gases; a second step of calculating a content ratio (%) of each dissolved gas from the total content of the four dissolved gases selected from the extracted five dissolved gases; and a third step of determining the internal fault of the oil-immersed transformer for diagnosis corresponding to an internal fault region according to content ratio (%) values of the calculated four dissolved gases and predetermined content ratios (%) of the four dissolved gases.

主权项

1. A method of diagnosing an internal fault of an oil-immersed transformer through a combination of content ratios of dissolved gases, which is capable of analyzing the dissolved gases contained in the insulation oil of the oil-immersed transformer of which the internal fault is able to be diagnosed, the method comprising:
a first step of extracting H2, CH4, C2H2, C2H4, and C2H6 from the dissolved gases; a second step of selecting four dissolved gases, classified depending on each internal fault, from the five extracted and dissolved gases, so as to calculate a content ratio of each dissolved gas to a total content of the four selected and dissolved gases; and a third step of determining a type of the internal fault of the immersed transformer for the diagnosis by enabling one to four combinations, which are selected from combinations of % H2 and % CH4, % H2 and % C2H2, % C2H4 and % C2H2, % C2H4 and % CH4, % H2 and % C2H6, and % C2H4 and % C2H6 which are calculated, to correspond to a predetermined internal fault region.