Remaining life diagnosis method and remaining life diagnosis device for power distribution equipment

摘要

PROBLEM TO BE SOLVED: To provide a remaining lifetime diagnosis method and device capable of diagnosing a remaining lifetime of a solid insulator of power reception/distribution equipment accurately in an online state.SOLUTION: By using a humidity-independent surface resistivity evaluation technique, humidity-independent surface resistivity of an insulator to be diagnosed included in power reception/distribution equipment is acquired (S1). A sensor insulator formed from the same or equal material as or to the insulator to be diagnosed is installed in the power reception/distribution equipment (S2). The measured surface resistivity of the sensor insulator is successively converted into surface resistivity of the insulator to be diagnosed while using first and second conversion coefficients (S4 and S5). The first conversion coefficient corresponds to a difference of surface resistivity between the insulator to be diagnosed and the sensor insulator when installing the sensor insulator in the power reception/distribution equipment. The second conversion coefficient corresponds to a difference between a reduction speed of the surface resistivity of the insulator to be diagnosed and a reduction speed of the surface resistivity of the sensor insulator.