基于超声波的沟槽电缆局部放电检测技术

摘要

为了检测沟槽电缆绝缘层局部放电区域,文中提出了一种基于超声波的局部放电在线检测技术.基于绝缘层三电容模型和气隙放电模型,分析局部放电产生超声波的机理及信号特征;研究了高灵敏度、便携式沟槽电缆局部放电超声波在线检测装置;基于MATLAB的GUI功能研究了数据处理系统.测试结果表明:该装置能可靠地采集处理局部放电超声波信号,且信号幅值与放电量成正比,与传播距离成反比;在局部放电信号频率范围内,低频段放电信号的幅值较大.%In order to detect the local discharge area of the trench cable insulation layer , an online detection technology of partial discharge based on ultrasonic was proposed in this paper .The mechanism and signal characteristics of ultrasonic discharge were analyzed based on the three-capacitance model of the insulation and the air-gap discharge model .The online detection device of high-sensitivity and portable trench cable partial discharge ultrasonic was studied .The data processing system was studied based on the GUI function of MATLAB .The test results show that the device can reliably collect and deal with the partial discharge ul -trasonic signal , the signal amplitude is proportional to the discharge quantity and is inversely proportional to the propagation dis -tance.In the frequency range of the partial discharge signal , the amplitude of the low frequency band discharge signal is large .