Study on the Applicability of Defect Detection Methods for Internal Voltage Balancing Capacitor Tubes in Ultra-UHV Surge Arresters

Targeting accidents caused by the loosening or detachment of internal voltage-balancing capacitor tubes in station-used 750kV gapless metal oxide surge arresters, this paper has investigated portable partial discharge measurement methods including HFCT, UHF, ultrasonic, and oscilloscope techniques under controlled laboratory conditions simulating eight specific scenarios. The study included interference resistance trials with varying degrees and distances of ladder interference, comparing outcomes with traditional resistive current testing. It concludes by identifying field-applicable detection methods for these types of defects, enhancing the arsenal of effective on-site partial discharge measurement tools for surge arresters.