When the traditional piezoelectric ceramic ultrasonic sensors detect the partial discharge of a cable
there is an acoustic interface mismatch phenomenon. The partial discharge ultrasonic signal is severely attenuated during the propagation process. Therefore
the traditional piezoelectric ceramic ultrasonic sensor cannot detect the partial discharge of the cable with high sensitivity. In response to this phenomenon
a flexible ultrasonic sensor based on lead zirconate titanate (Pb(Zr0.52
Ti0.48)O3
PZT) piezoelectric film is designed and prepared according to the principle of acoustic impedance matching and the electromagnetic shielding requirements. The influence of different polarization modes on the sensitivity of the flexible sensor is studied
and the electromagnetic shielding performance
sensitivity curve and directional sensitivity of the flexible sensor after packaging are tested. On this basis
the partial-discharge ultrasonic-signal detection experiment of the real cable air gap model based on the flexible sensor is carried out. The results show that the flexible sensor designed and prepared in this paper has good electromagnetic shielding performance and no directional sensitivity. The average and peak values of the sensitivity in the range of 30~200 kHz are 51.8 dB and 53.8 dB
respectively. In the ultrasonic detection of air gap discharge of the real cable
the detection sensitivity of the flexible sensor is 1.57 times that of the traditional piezoelectric ceramic ultrasonic sensor.