External UHF Sensor for GIS PD Insulation Defect from Resin Hole

In view of the effective perception demand PD (Partial Discharge) insulation defect in-service GIS (Gas Insulated Switchgear), external UHF (Ultra High Frequency, 0.3−3 GHz) sensing technology for from resin hole is studied in this paper. Firstly, rectangular waveguide theory used to analyze electromagnetic wave propagation characteristics disc insulator. It found that energy leaked mainly concentrates frequency band above 1 GHz. Then based on characteristics, a cavity-backed bowtie sensor detection designed optimized by HFSS finite element software, 1–3 GHz, its maximum VSWR 7, minimum 1.1, average 2.9, and 0.3–1 42.8 20.6. Finally, prototype made, sensitivity experiment carried out 220 kV GIS, experimental results show can stably detect signal hole, range consistent with theoretical analysis results.