Online Monitoring Strategy of High Voltage Assets in AIS based on Partial Discharge Detection by Radiometric Method

This paper presents the application of the radiometric (UHF) method for partial discharge (PD) detection in high-voltage assets in a power generation company. Vehicle-based radiometric inspections enabled rapid identification of PD signals. Two case studies are presented, specially a 245 kV capacitive voltage transformer, with laboratory tests confirming PD levels above 300 pC in the capacitive section. Complementary techniques, including HFCT and acoustic methods, supported the diagnosis. The radiometric approach allowed early detection of insulation deterioration, optimizing maintenance and replacement strategies. The results highlight the effectiveness of radiometric PD detection for predictive maintenance and asset management in air-insulated substations.