基于屏蔽层载波通信的电力电缆在线监测研究

发布时间：2018-09-17 19:48

【摘要】：随着中国城市化进程的发展,地下电力电缆在输配电线路中所占比例不断增加。电缆故障将可能给企业和社会带来重大经济损失,甚至是人员伤亡。因此,监测电缆状态,预防电缆故障,具有理论价值和现实意义。由于具备优良的电气性能,交联聚乙烯电力电缆受到了广大用户的欢迎。其制造工艺日趋成熟,在高压和超高压领域使用量不断增加,在城市输配电网络中所占比重逐年上升,表现出替代纸绝缘电缆的趋势。电力线载波通信以电力线为通信介质,具有投资少,覆盖范围广,无须额外布线,易于扩展改造等优势,被广泛应用在电力通信网络中。传统的电力线载波通信以带电的电力线为信道,利用电力电缆金属屏蔽层进行载波通信,是近年来才发展起来的一项新技术,成为国内外电力等相关机构的研究热点,在城市小区配电自动化中得到了成功应用。本文利用Matlab软件仿真研究电力电缆金属屏蔽层载波通信系统。通过仿真,得到信源在模型中各个节点传输时的波形变化情况和误比特率曲线。并且以交联聚乙烯电缆为对象,以电缆金属屏蔽层为信道,基于电力线载波通信技术,构建电力电缆在线监测系统,设计硬件电路并进行相关实验。主要研究内容如下：首先,介绍交联聚乙烯电缆各层结构特点及其作用,分析金属屏蔽层信道传输特性与噪声环境,对电力线载波通信中常用的调制解调技术进行介绍。其次,利用Matlab软件仿真分析屏蔽层载波通信系统,分别采用2FSK和DSSS技术,设计出六种仿真模型,分析信号传输过程中的变化情况,得出模型误比特率曲线。再次,设计电力电缆在线监测系统硬件电路,包括电源电路、信号采集电路、信号处理电路和信号显示电路等。然后,设计电力电缆在线监测系统软件程序,包括下位机程序和上位机程序两个部分。最后,对设计的在线监测系统进行分模块调试和整机实验,测量实验波形,分析实验数据。实验结果表明,本系统接线简单方便,硬件成本低廉,监测效果良好,特别适用于地下直埋电力电缆和早期无复合光纤通信的海底电力电缆的信号传输等场合。本文研究对于电力电缆在线监测和城市小区配电自动化等具有一定的参考价值。
[Abstract]:With the development of urbanization in China, the proportion of underground power cables in transmission and distribution lines is increasing. Cable failure may bring great economic losses to enterprises and society, even casualties. Therefore, it is of theoretical and practical significance to monitor cable status and prevent cable faults. Because of its excellent electrical performance, cross-linked polyethylene power cable is welcomed by the majority of users. Its manufacturing technology is becoming more and more mature, its usage in the field of high voltage and ultra high voltage is increasing, and its proportion in urban transmission and distribution network is increasing year by year, showing the trend of replacing paper insulated cable. The power line carrier communication takes the power line as the communication medium, has the advantages of less investment, wide coverage, no additional wiring, easy to expand and transform, and is widely used in the power communication network. The traditional power line carrier communication takes the live power line as the channel, uses the power cable metal shield layer to carry on the carrier communication, is a new technology developed in recent years, becomes the domestic and foreign power and so on related organization research hot spot. It has been successfully applied in distribution automation of urban district. In this paper, Matlab software is used to simulate the power cable metal shielded layer carrier communication system. Through simulation, the waveform change and bit error rate curve of each node in the model are obtained. Taking the XLPE cable as the object and the metal shield layer of the cable as the channel, based on the power line carrier communication technology, the on-line monitoring system of power cable is constructed, and the hardware circuit is designed and related experiments are carried out. The main research contents are as follows: firstly, the structure characteristics and functions of each layer of XLPE cable are introduced, the transmission characteristics and noise environment of metal shielded layer channel are analyzed, and the common modulation and demodulation techniques in power line carrier communication are introduced. Secondly, six kinds of simulation models are designed by using Matlab software to simulate and analyze the carrier communication system in shield layer. Six simulation models are designed by using 2FSK and DSSS techniques, and the BER curve of the model is obtained. Thirdly, the hardware circuit of power cable on-line monitoring system is designed, including power supply circuit, signal acquisition circuit, signal processing circuit and signal display circuit. Then, the software program of power cable on-line monitoring system is designed, which includes two parts: lower computer program and upper computer program. Finally, the designed on-line monitoring system is debugged and tested, the experimental waveform is measured and the experimental data are analyzed. The experimental results show that the system has the advantages of simple and convenient connection, low hardware cost and good monitoring effect. It is especially suitable for the signal transmission of underground buried power cables and early submarine power cables without composite optical fiber communication. The research in this paper has certain reference value for power cable on-line monitoring and distribution automation in urban residential areas.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM75

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