【作者】 鲁美连；

【导师】 魏丰；

【作者基本信息】 华中科技大学 ， 检测技术与自动化装置， 2007， 硕士

【摘要】 随着电力系统自动化技术的发展,电力系统授时钟同步精度的要求越来越高,电力系统也日趋网络化,如数字化变电站。而传统的时钟同步方法单一,不能将整个电力系统网内装置同步。为此,本文开发了一种既有网络同步授时功能、又有传统授时功能的嵌入式NTP网络同步时钟源,该时钟源能够为电网自动化设备如微机故障录波及事件记录等智能设备提供精确时间。本文从如何实现网络时钟同步的问题着手,在研究现有的网络时钟同步协议基础上,研究开发了一种嵌入式NTP网络同步时钟源,实现了局域网内的网络时钟同步。具体来说,本文主要完成了以下几个方面的工作:本论文深入研究了现有的网络时钟同步协议,着重分析了NTP协议的工作原理和报文格式,结合电力系统的实际,提出了此次设计所要达到的同步精度。本论文提出嵌入式NTP网络同步时钟源的设计方案,完成了整个系统的硬件和软件开发。系统以Rabbit 2000微处理器为核心,实现了NTP网络时钟同步,同时也提供脉冲授时信号和串口授时信号。采用Dynamic C完成系统的软件开发,提出了一种时间标记方案,精确标记NTP同步报文到达和离开节点的时刻。本论文采用Delphi语言编写客户端授时程序,对嵌入式NTP网络同步时钟源进行了测试,测试结果表明本文所设计的网络时钟源能同步局域网内的从节点,同步方式简便,具有较大的应用价值。更多还原

【Abstract】 With the development of automatic technology of electric system, the need of clock synchronization’s precision is more and more exigent, the electric system is trending to networklize,for example, the digital transformer substation. But traditional clock synchronization method existing compares time singly, it can’t synchronize the time of the entire electric system’s devices. So, this thesis has developed an embedded network synchronization clock based on NTP, which is used for network time synchronization and traditional time comparing. This clock can provide precise time for automatic device of electric system such as PC malfunction to record wave and event.This thesis starts from how to implement the clock synchronization, on the base of studies of existing network synchronization protocols, and develops an embedded network synchronization clock based on NTP, implementing the function of network time synchronization in LAN using NTP.Specifically, this thesis includes the following aspects:This thesis has lucubrated existing network clock protocols, mainly analyzing the NTP protocols’working principles and message format, combining the practice of electric system, putting forward the time comparing precision of this design.This thesis has proposed a designing schema of embedded network synchronization clock based on NTP, having done the entire development of hardware and software system. The system is based on the core of Rabbit 2000 micro processor, and implementing the NTP network time synchronization function, providing pulse time comparing signal and serial-port time comparing signal. The software is developed using Dynamic C. Bring forward a scheme that can identify a time less than a second, and then we can get the exact time when the NTP synchronous messages arrive at the node and leave.This thesis has used Delphi to write the client time comparing program to test the embedded NTP network synchronization clock, the test results indicate that the network clock of this paper has high precision, convenient to use, and has great value in practice.更多还原