Research on Miniaturized and Wideband UHF Sensing Technology for Partial Discharge Detection of Power Equipment Based on Serpentine Bending

Aiming at the problems of large size and narrow bandwidth of ultrahigh-frequency (UHF) sensors for partial discharge (PD) detection in power equipment, this article designs a UHF monopole sensor based on serpentine bending technology, which realizes the miniaturization of the sensor under the prerequisite of guaranteeing the detection performance. The sensor size is only
$70\times 70\times 1.6$
mm, nearly 71.3% smaller than the conventional monopole structure. The performance of the designed sensor is simulated, optimized, and measured, and the results show that the voltage standing wave ratio (VSWR) of the designed UHF sensor is less than 2 in the frequency band from 300 MHz to 1.24 GHz. In the frequency band from 300 MHz to 1.5 GHz, the VSWR is less than 3, which meets the requirements of the broadband system. At the same time, the radiation characteristics of the sensor are good, the H-plane has a maximum gain of 9.79 dB and an average gain of −0.34 dB, and the E-plane has a maximum gain of 15.5 dB and an average gain of 2.5 dB. Finally, the experimental platform for PD detection of power equipment is set up to test the sensing performance of the sensor, and the experimental results show that the sensor can effectively detect PD signals with high sensitivity, which meets the demand for PD detection of power equipment.