High voltage disconnector is an important electrical equipment in power system and its mechanical fault will have an adverse affect on the safe operation of power grid. However

the research on intelligent fault diagnosis of disconnector is presently still in the preliminary stage. For this reason

type GW5-35 disconnector from a certain company is taken as the experimental prototype and a gyroscope based attitude angle measurement system is set up. The attitude angle-time curve and speed-time curve of such five states as normal state

sand deposition on contact

loose-ness of limit bolt of travel switch

looseness of bolt of bearing housing and looseness of inter pole linkage stud are measured. A feature extraction method is proposed to divide the closing process of the disconnector into three stages and extract 14 features. The typical operating process and fault performance of the disconnector under above five states are analyzed in detail. Finally

the typical fault feature table and the fault diagnosis reference flow of the disconnector are provided

which can provide reference for the mechanical fault diagnosis of the disconnector and basic da-ta for intelligent operation and maintenance of substation as well.