Novel High Frequency Antenna Sensor to Detect On-Line Partial Discharge Signals

The timely detection of partial discharge (PD) of high-voltage (HV) power equipment is crucial to mitigate serious consequences such as the degradation of insulation and equipment failure. The ultra-high frequency (UHF) detection method stands out for its efficacy in this regard. In this study, a novel UHF antenna sensor is proposed for PD detection. The antenna's offset structure enables it to detect PD events near a conducting ground wire without being clamped to the wire like the typical high-frequency current transformer (HFCT). Meanwhile, its equivalent circuit is modeled as a ladder-structure band-pass filter (within the consideration of mutual inductances) to realize its wideband properties. Fabricated on a substrate and integrated with a low-noise amplifier, the antenna sensor exhibits a broad impedance bandwidth between 1 MHz and 108 MHz, as demonstrated through measurements in an anechoic chamber. In-lab and on-site systematic experiments affirm the efficiency of the proposed antenna sensor in PD detection. Notably, the Phase-Resolved Partial Discharge (PRPD) pattern is distinctly observable at the backend through Internet connectivity, further confirming the overall monitoring capabilities.