基于电力载波监控系统实现.docVIP

姓 名： 姓 名： 李京伟 学 号： 班 级： 07自动化1 专 业： 自动化 所在系： 自动化工程系 指导老师： 郭 丹 毕业设计 基于电力载波的监控系统的实现 基于电力载波的监控系统的实现 摘 要 近年来，通过配电网实现通信，又称低压电力线载波通信（PLC）越来越引起人们的广泛关注。电力线载波通信的许多优点为电力市场以及相关业务的发展提供了广阔的应用前景。特别是，这种通信方式可以利用现有的深入到千家万户的供电网络，而成为一种易于接入、方便使用且成本低廉的理想选择，因此，利用电力线通信技术构建针对家庭或楼宇的智能监控系统，是一种很有潜力的方案。然而，电力线网络总是处于强噪声环境下工作，电力线的低通特性、频率选择性衰减、网络阻抗的不匹配、信号的反射和折射以及严重的噪声干扰导致的小信噪比（SNR）等都会给电力线通信带来困难。 本文研究了低压电力线通信技术在监控系统中应用的可行性。概要介绍了低压电力线通信技术的理论研究和工业应用现状。结合实测数据，分析了低压电力线信道的低输入阻抗、高噪声、强衰减特性。设计了一个基于单片机和电力载波芯片的电力线通信系统的硬件平台。从而实现了基于电力线通信的远程监控系统。 关键词：低压电力线载波通信 单片机 耦合电路 Monitoring System Based On The Power Line Communications ABSTRACT The usage of electrical power distribution networks as a media for communications, called Power line Communications (PLC), has become more and more attractive in recent years. It has a number of advantages that attract great interest for the development of electrical market and business opportunities. The main attractive feature of this kind of media is due to its ubiquity. Indeed nowadays all urban, suburban and rural areas are fully covered by transmission and distribution electricity grid for devlivering energy services. Its ubiquity makes it an ideal media for surveillance and control applications. However, power line communication channel is well known by experts as one of the most complex to characterize. It is often said that power line acts as hostile environment. Besides the low pass characteristic of the channel and the frequency selective fading, the impedance mismatching, the signal reflection and the impulse noises crucially affact the Signal to Noise Ratio (SNR). In this thesis, we present the possibilities of applying PLC in the communication access networks. A concise summary of the state of the art of the theory and practice of Power line Communication is presented. The power line channel characteristics is analyzed based on measurement data. Some tips are given for PLC modem development to utilizing the characteri