Abstract:The application of ultrasonic sensing technology is expected to achieve online monitoring of cable partial discharge. Therefore, it is necessary to study the acoustic frequency and amplitude attenuation rules of partial discharge in a certain type of cable. Taking the YJV?185 mm2 type 10 kV XLPE power cable as research object, this paper carries out simulation calculations of two sets of different frequency acoustic sources and a set of "needle?hole" partial discharge experiment. The frequency and amplitude attenuation rules of partial discharge acoustic signals in the cable are studied. Research results show that the attenuation law of acoustic waves in multi?layer complex media is inconsistent with that in a single medium. The influence of the frequency composition of the sound source on the detectable sound frequency and amplitude of the cable surface cannot be ignored. The acoustic source model of the "needle?hole" partial discharge in the cable can be approximated as a Gaussian pulse with a bandwidth of 1 MHz, a peak time of 1μs, and a frequency in the range of 0~1.5 MHz. The radial attenuation coefficient of the "needle?hole" partial discharge acoustic signal in the cable sample is about 8.17 dB/mm, the axial attenuation coefficient on the cable surface is about 0.43~0.52 dB/mm, and the detectable acoustic frequency range on the cable surface is 0~40 kHz. The center frequency of high sensitivity sensors is recommended to be designed at 20~40 kHz, while the design of distribution density of distributed detection sensors require specific research on specific issues.