针对电力系统中高压多芯电缆的损伤难以准确检测的问题，对基于超声导波的高压多芯电缆损伤缺陷检测方法进行了研究。分析了导波在电缆中的传播特性，研究了整套超声导波无损检测试验装置，利用PZT探头进行了导波的激励与接收换能，制作了用于固定电缆以及超声探头的夹具，并且在长电缆上进行了试验，采用小波去噪以及小波变换对缺陷点反射回来的信号进行了去噪及特征提取分析。结果表明，信号的信噪比显著提升，可以准确识别出微弱回波信号，实现了对导波发射端左右两端共20 m范围内的缺陷检测。

Aiming at the problem that the damage of high-voltage multi-core cable in power system is difficult to detect accurately, the detection method by using ultrasonic guided wave was studied. The propagation characteristics of the guided wave in the cable were analyzed, and a complete set of nondestructive testing equipment for ultrasonic guided waves was studied as well in which the excitation and reception of the guided wave was realized by using the PZT probe. Fixtures for the fixed cable and the ultrasonic probe were designed and fabricated. All the above-mentioned ones were tested on a long cable. Wavelet transform was used to denoise and extract features on the reflection from the defect. The results showed that the signal to noise ratio of the signal was improved. The weak echo signal could be accurately identified. Defect detection for both ends of the transmitter within 20m was achieved.