Study on Extraction Method of Resistance Leakage Current of Zinc Oxide Arrester
Arrester is an important protection equipment in high voltage substation and high voltage converter sta-tion.It can protect electrical equipment from overvoltage harm and protect the insulation level of electrical equip-ment.Zinc oxide arrester has the advantages of strong nonlinearity and strong current flow ability,which can im-prove the reliability of power system.The main reasons for the failure of zinc oxide arrester are aging and damp-ness,which leads to the increase of leakage current and the rise of internal temperature,leading to the thermal col-lapse of arrester.In the resistance leakage current of zinc oxide arrester,the fundamental wave component can char-acterize its internal damp condition,and the harmonic component can characterize its aging condition.Therefore,the working state of the arrester can be monitored by extracting the resistance leakage current.In this paper,resistive current is extracted by capacitive leakage current compensation method,and a simulation model is built.The simu-lation results show that this method can accurately extract the resistive leakage current.