Research on Ultrasonic-UHF Interdigital Structure Single Sensor for Partial Discharge Detection

In view of the complex electric field, the internal field of power equipment will have different degrees of distortion, so that the local electric field outburst will be strengthened, and partial discharge (PD) will occur, which will affect the stable operation of power equipment. In order to realize simple and reliable PD joint detection of power equipment under complex electric field, based on the sensing principle of piezoelectric ultrasonic method and the sensing principle of two-dimensional planar ultra-high frequency (UHF), a structure model of lead zirconate titanate substrate sensor with the function of simultaneously sensing PD ultrasonic signal and electromagnetic wave signal is constructed by using omnidirectional annular interdigital electrode structure. The three-dimensional acoustic and electromagnetic simulation optimization of the sensor is constructed by COMSOL and ANSYS HFSS respectively. The simulation results show that: The average ultrasonic sensing sensitivity of the ultrasonic- UHF interdigital structure single sensor designed in this manuscript is 20.5dB in the frequency band of 20kHz~200kHz; the electromagnetic wave sensing VSWR<5 in the 0.33GHz~2.5GHz band. This manuscript solves the problem that the ultrasonic method and UHF method commonly used in PD detection of power equipment cannot use a single sensor to perceive two signals at the same time, and provides a new solution to the simple and reliable perception of PD in power field.