Research on Characteristics and Calibration Method of Gas Relay of Power Transformer in Power Grid

Abstract

Large-scale power transformer is one of the core equipments in power system. Once it breaks down, it will bring great harm to power grid. Especially when the internal turn-to-turn short-circuit fault occurs, the high temperature and arc caused by the short-circuit current will not only burn out the transformer winding insulation and iron core, but also cause the transformer insulating oil to be decomposed by heat and produce a large amount of gas, thus causing the deformation, damage and even explosion of the transformer shell. Therefore, once the transformer fails, it must be removed from the power system in time. At present, for power transformers, relay protection can be divided into electric protection and non-electric protection. Electrical relay protection mainly includes differential protection, current quick-break protection and zero-sequence current protection. Non-electric relay protection mainly includes heavy gas protection, light gas protection, pressure release protection and quick-acting oil pressure protection. This paper introduces the working principle of common non-electricity protection devices, and theoretically analyzes the cooperation between non-electricity protection devices. In view of gas relay, this paper introduces the requirements of relevant standards for gas relay, sums up the matters needing attention in field use of gas relay, and analyzes the factors affecting the performance of gas relay. The application status and characteristics of gas relay in Heilongjiang power grid are investigated, and the problems in management are pointed out. Using the calibration platform, through a large number of experiments, the influence of caliber and gas relay action on the performance parameters of gas relay is studied. And it is ensured that safe and reliable operation of the power transform of the power grid.