变电站无间隙金属氧化物避雷器劣化预警方法和装置开发OA

Due to bearing system voltage in long-term operation and accidental short-time overvoltage,a slow deterioration process characterized by the increase of resistive current is generated on the arrester.Moreover,under repeated lightning stroke condition,the lightning arrester absorbs more lightning energy in a short time,causing a rapid deterioration process of internal resistor and increasing the risk of thermal collapse.A method and criterion for evaluating the deterioration of lightning arresters are proposed.A slow deterioration criterion with a threshold of twice the resistive current and a fast deterioration criterion with a threshold of 30％of the current carrying capacity of the accumulated lightning energy absorbed in a short period of repeated lightning stroke are given.On this basis,a lightning arrester deterioration warning method consisting of two types of warnings:slow degradation and rapid degradation,as well as a corresponding lightning arrester degradation warning device are proposed to realize timely perception of the deterioration trend information and fault warning of the gapless arrester in existing substations,which helps to avoid the thermal collapse fault of the arrester.