基于交流耐压的高压电缆分布式局放检测技术研究与应用

发布时间：2018-07-25 20:05

【摘要】：随着国民经济的高速增长,城市化建设的进程日益发展,对于提高供电可靠性和稳定性的需求也越来越迫切。市区内的高压输电通道出于市政规划,所处环境以及人身安全等因素的考虑,电力电缆使用率激增。电缆化率提升的同时,系统的电容电流也随之增大,由于绝缘缺陷导致的接地故障电弧不易熄灭,进而扩大故障范围,引发严重事故。电缆多敷设于隧道内或地面下,且距离较长,内部的绝缘缺陷排查较为困难。近年来,由于电缆内部绝缘缺陷、接头位置制作和安装工艺缺陷而导致的起火、大面积停电等事故时有发生。因此,应在投运前对电缆进行彻底检测,避免带有绝缘缺陷的设备入网运行。针对上述问题,本文研究了基于交流耐压的局部放电检测技术对电缆内部及接头位置潜在的绝缘缺陷进行检测的方法,并设计了一套基于高频脉冲法的分布式局放测试系统,对电缆内部、中间接头及终端头进行检测。系统通过无线通讯的方式对各检测单元的采集数据进行传输,利用神经网络对测试图谱进行模式识别,以确定局放信号产生的位置和类型,实现故障定位。本文的主要工作内容有:1)根据电力电缆局部放电的放电规律,研究了局放信号在电缆中传输特性,建立局放模型、电缆电路模型、局放信号传输模型;2)针对电力电缆内部绝缘缺陷在交流耐压过程中不易发现的问题,设计了基于交流耐压的分布式局放测试系统,对电力电缆内部和接头位置的内部绝缘缺陷进行检测,利用无线通讯的方式对各个检测单元采集到的高频脉冲信号进行传输和同步,实现故障定位。3)通过收集整理模拟试验和现场试验的研究结果,建立了典型缺陷特征谱图数据库。并利用人工神经网络,对检测单元采集到的局部放电信号进行分析处理,实现电力电缆内部绝缘缺陷类型的模式识别。
[Abstract]:With the rapid growth of national economy and the development of urbanization, it is more and more urgent to improve the reliability and stability of power supply. Due to the consideration of municipal planning, environment and personal safety, the utilization rate of HV transmission lines in urban areas has increased dramatically. With the increase of the cable conversion rate, the capacitance current of the system increases, and the grounding fault arc caused by the insulation defect is difficult to extinguish, thus expanding the fault range and causing serious accidents. The cables are mostly laid in the tunnel or under the ground, and the distance is long, so it is difficult to check the internal insulation defects. In recent years, due to internal insulation defects, joint position manufacturing and installation process defects caused by fire, large-scale power outages and other accidents have occurred from time to time. Therefore, the cable should be thoroughly tested before commissioning to avoid the equipment with insulation defects into the network operation. In order to solve the above problems, this paper studies the method of detecting the potential insulation defects in cable and joint position based on AC voltage and partial discharge detection technology, and designs a distributed partial discharge testing system based on high frequency pulse method. Check the cable interior, intermediate connector and terminal head. The system transmits the collected data of each detection unit by wireless communication, and uses neural network to identify the pattern of the test spectrum, to determine the location and type of PD signal, and to realize fault location. The main work of this paper is as follows: (1) according to the law of partial discharge of power cable, the characteristics of partial discharge signal transmission in cable are studied, and the partial discharge model and cable circuit model are established. In order to solve the problem that the internal insulation defect of power cable is difficult to find in the process of AC voltage resistance, a distributed PD test system based on AC voltage is designed. The internal insulation defects of power cable and joint position are detected, and the high frequency pulse signals collected by each detection unit are transmitted and synchronized by means of wireless communication. Through collecting the research results of simulation test and field test, the typical defect characteristic spectrum database is established. Using artificial neural network, the PD signals collected by the detection unit are analyzed and processed to realize the pattern recognition of the internal insulation defects of power cable.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM835

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