Method for calculating influence of electric arc on oil flow rate in switching process of on-load tap-changer

Abstract

The invention relates to a method for calculating the influence of an electric arc on an oil flow rate in the switching process of an on-load tap-changer. The method comprises the steps: calculating electric arc energy: calculating the integral of voltage and current at two ends of the electric arc within the duration of the electric arc; calculating the volume of produced gas: calculating the volume of the produced gas according to the ratio of the electric arc energy to the energy required for producing the unit volume of gas; establishing a temperature field and fluid field coupling calculation model; and calculating the oil flow rate. The invention further discloses a system for calculating the influence of the electric arc on the oil flow rate in the switching process of the on-load tap-changer. By quantitatively characterizing the energy generated by the electric arc, the method and system can be suitable for transformers of different voltage classes; simulation software is introduced into bidirectional coupling of a temperature field and a fluid field, and a certain theoretical basis is provided for accurately calculating the influence of the electric arc on the oil flow rate in the switching process of the on-load tap-changer and practically improving the reliability of non-electric quantity protection actions.

Description

technical field [0001] The invention relates to the technical field of transformer state monitoring, in particular to a calculation method for the influence of an arc on the oil flow rate during switching of an on-load tap changer. Background technique [0002] The on-load tap changer is equipped with an on-load switch, which not only stabilizes the load center voltage, but also is an important device for connecting the power grid, adjusting the load flow and improving reactive power distribution. Its safe operation is directly related to the stability of the system. As the only mechanical part in the transformer that operates quickly under high voltage and high current, the on-load switch is frequently used in the process of voltage regulation and is prone to failure, which will directly affect the normal operation of the power transformer. In recent years, with the rapid development of the national economy and society, the capacity of a single transformer has been increasi...

AI Technical Summary

Problems solved by technology

Judging from the data analysis of many gas protection misoperation accidents that occurred in recent years, the reliability of gas protection is still very low, and misoperation and refusal to operate are very easy to occur. The root cause lies in outdated protection principles and inaccurate actions. threshold

Although some production units and scientific research institutions have extensively analyzed the causes of heavy gas protection misoperation and proposed corresponding solutions, they still cannot effectively prevent the occurrence of heavy gas protection misoperation accidents.

For high-voltage, large-capacity transformers equipped with oil arc-extinguishing on-load switches during normal switching, there are no relevant research reports on the mechanism of arc energy causing oil flow surges inside the transformer and on-load misoperations, and relevant research is urgently needed

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