Research on Integrated Technology of PD Ultrasonic Signal and UHF Signal Detection

The construction of new power systems places higher demands on the intelligent sensing of the operating status of key power equipment, in view of the complex structure of the comprehensive detection system for PD of power equipment caused by the single function of the current ultrasonic signal and high-frequency electromagnetic wave sensing system, as well as ultrasonic sensors and UHF antenna sensors are rigid structures, which will lead to complex installation on arc-shaped power equipment, this paper presents the research on the integration technology of partial discharge ultrasonic signal and high-frequency electromagnetic wave signal perception, PVDF piezoelectric material is used as the substrate, and interdigital electrode as sensing unit, establish an integrated structural model of ultrasonic and high-frequency electromagnetic wave sensing. The ultrasonic sensing performance and UHF electromagnetic wave sensing performance of the integrated sensor are simulated and analyzed by Piezoelectricity-Solid module in COMSOL and HFSS respectively. The simulation results show that: For ultrasonic signals in the frequency range of 20kHz to 200 kHz, when the frequencies are 52.1khz, 89.3khz, 94.8khz, and 171khz, the surface displacement of the integrated sensor exceeds 0.0025mm, under the signal of 94.8khz, the maximum surface displacement is 0.044mm, and the acoustic-electric conversion efficiency is the highest, this indicates that the integrated sensor senses signals in the range of 20kHz∼200kHz; for 0.3GHz∼3GHz UHF electromagnetic wave signal, in the 0.4GHz ∼ 0.45GHz, 0.55GHz ∼ 0.6GHz and 1.7GHz ∼ 3GHz, the VSWR of the integrated sensor is ≤ 5 and reflected power is ≤ 44.44%. This designed integrated sensor has the feasibility of sensing partial discharge radiation ultrasonic signal and high-frequency electromagnetic wave signal at the same time.