摘要
超声传感技术的应用有望实现电缆局部放电的在线监测,因此有必要对相应型号电缆局放声波频率及幅值的衰减规律进行研究。基于型号为YJV-185 mm2的10 kV XLPE电力电缆,结合2组不同频率声源的仿真计算和1组“针—孔”局放实验,研究局放声波信号在电缆中的频率及幅值衰减问题。研究结果表明:声波在多层复杂介质中的衰减规律和在单一介质中的衰减规律不一致;声源频率组成对电缆表面可检测声波频率及幅值的影响不可忽略;电缆中“针—孔”局部放电的声源模型可以近似为带宽为1 MHz、峰值时间为1μs、频率范围为0~1.5 MHz的高斯脉冲;本文所用型号电缆的“针—孔”局部放电声波信号在电缆中的径向衰减系数值约为8.17 dB/mm,电缆表面的轴向衰减系数为0.43~0.52 dB/mm,电缆表面的可检测声波频率为0~40 kHz;高灵敏度传感器的中心频率建议设计为20~40 kHz,而分布式检测传感器分布密度的设计需要具体问题具体研究。
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.
作者
罗海静
柳赟
LUO Haijing;LIU Yun(School of Electrical and Electronic Engineering,North China Electric Power University,Beijing 102206,China)
出处
《电力科学与技术学报》
CAS
CSCD
北大核心
2023年第2期186-195,共10页
Journal of Electric Power Science And Technology
基金
中央高校基本科研业务费专项资金资助(2019MS005)。
关键词
XLPE电缆
局部放电
声波衰减
衰减系数
中心频率
XLPE power cable
partial discharge
acoustic attenuation
attenuation coefficient
center frequency
