电气工程及其自动化专业毕业论文.doc

I 电力载波通信抄表集中器硬件设计摘要随着我国电力事业的迅速发展,传统的用电抄收管理方式己经不能满足市场需求。本文在大量收集查阅国内外有关远程抄表系统资料、深入用户及用电管理部门广泛调研的基础上,提出了一种采用低压电力线载波通信技术的远程自动抄表系统。该系统具有三层网络结构,即上位机管理系统、集中器和载波电表。重点分析研究了集中器及其与各组成部分的通信。由于我国低压电力线上存在的高削减、高噪声、高变形,必须采用特殊的通信技术。本文首先分析了高频信号在电力线中的传输特性;重点讨论了扩频通信技术在电力线载波通信中的应用;深入研究了以扩频调制解调技术通信技术为基础的、高性能的电力线载波专用 MODEM 芯片 SSC P300 的内部工作原理。在此基础上,采用 SSC P30 0 实现了远程抄表系统中集中器与终端载波电表之间可靠的数据传输。集中器是连接上位机与终端载波电表之间的枢纽,起着上传下达的作用。根据中华人民共和国电力行业标准规定的集中器的主要功能及性能指标要求,本文重点研究设计了集中器的硬件系统。其中硬件系统主要包括主控制器、外部扩展数据存储器、时钟模块、看门狗模块、上位机通信接口电路以及电力线载波通信电路及其外围电路等。关键词:电力线载波,扩频通信技术,集中器,抄表系统 II H ardware D esign of Power munication M eter R eading C oncentrator ABSTRACT With the rapid development of power undertaking ofour country, the traditional ways of meter reading can not satisfy the demand of market any more. Based on the vast collecting and consulting of the concerned information of the remote meter reading system of the home and abroad and going deep into the consumers and power consumption administrative departments to investigate and research widely, a remote meter reading system adopting munication technology of the low-voltage power munication (PLC) had been proposed in this paper . It work s tru c ture of three layers , i .e. puter administrative system , con c entrator and c arrier meter. And the functions and characteristics of the whole system together with its ponent had been analyzed. Be c ause high attenuation , high noise and high distortion exist in the low - voltage p ower lines ofour country ,spec munication technology must be adopted. First of all, the transmission chara c teristi c when high - frequency signal was transmitted through p ower lines was analyzed. Sec ondly , the application of spread munication technology to munication of the power line was emphatically di sc ussed. Thirdl y, the interior p rin cip leof the spec ial MODEM IC SSC P300 adopting Spread-spectrum munication technology was deeply studied. Based on this , SSC P300 was sele c ted to the reliable data transmission between