The Perfect Time: An Examination of Time- Synchronization Techniques
The Perfect Time: An Examination of Time- Synchronization Techniques
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完美时间：时间同步技术检验
DOI：
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发表时间：
2006
期刊：
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通讯作者：
K. Fodero
中科院分区：
文献类型：
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作者：
K. Behrendt;K. Fodero
各种情况的结合使得现在是研究电力系统监控设备时间同步技术的最佳时机：·由于2003年8月14日美国东北部和加拿大东南部停电后的干扰后分析所遇到的问题，电力系统监控设备的时间同步现在是中心舞台。NERC的建议，从这个postdisturbance分析的经验教训的基础上，把高度优先实施时间同步技术，将消除或减少涉及的工作与比较事件信息从分布式智能干扰记录设备。·成熟的同步相量测量技术也产生了对相距甚远的设备的非常精确的时间同步的需求。·全球定位系统（GPS）的高精度同步时间码信号现在可以通过经济的时钟接收器获得，这些时钟接收器设计用于在电力设施的恶劣环境中简单可靠地安装。·时间同步可以通过在公用事业和工业电力设施中变得越来越普遍的通信网络技术来实现。本文讨论了获取同步时间信号的可用技术、各种标准时间信号格式、将这些时间信号分配给监测和记录设备的技术以及各种电力系统计时和记录应用所需的相对精度。重点是监测和记录设备的精度要求，时间信号源的相对精度，时间信号分布对信号精度的影响，以及设备采样和处理对应用于采样数据的时间标签精度的影响。时间同步信号源包括基于地球的无线电传输（WWV、WWVH、WWVB和LORAN-C）、基于卫星的信号传输（GOES、GPS和GLONASS）以及经由通信网络和拨号调制解调器的时间设置消息。所有这些时标化信号和时间设置源通常可以追溯到由政府标准组织操作和提供的公共或协调的精确时间基准。协调世界时（UTC）已成为许多应用程序（包括大多数电力行业应用程序）事实上的标准时间参考。这一时间现在已成为公认的标准，因为它在全世界都可用，而且通过全球定位系统卫星时钟接收器获得这一时间也比较经济。本文重点介绍了利用GPS卫星作为时间同步源，比较和讨论了满足电力行业时间同步应用的各种时钟和时钟信号分配方法。本文附录中讨论了上述其他时间同步源，以供参考。
A combination of circumstances has made this the perfect time to look at time-synchronization techniques for power system monitoring devices: • Time synchronization of power system monitoring devices is now center stage because of the problems experienced with post-disturbance analysis following the August 14, 2003 blackout in the northeastern United States and southeastern Canada. NERC recommendations, based on the lessons learned from this postdisturbance analysis, place a high priority on implementing time-synchronization techniques that will eliminate or reduce the effort involved with comparing event information from distributed intelligent disturbance recording devices. • Maturing synchrophasor measurement technology is also creating a demand for very accurate time synchronization of devices in widely separated locations. • Global Positioning System (GPS) high-accuracy synchronized time code signals are now accessible through economical clock receivers that are designed for simple and reliable installation in the harsh environment of electric power facilities. • Time synchronization can be accomplished through communications network technologies that are becoming more prevalent in utility and industrial power facilities. This paper discusses available techniques to acquire synchronized time signals, various standard time signal formats, techniques for distributing these time signals to monitoring and recording devices, and the relative accuracy required by various power system timing and recording applications. Emphasis is given to the accuracy requirements of monitoring and recording devices, the relative accuracy of time signal sources, the effect that time signal distribution has on the accuracy of the signal, and the effect that device sampling and processing have on the accuracy of time tags applied to sampled data. Time-synchronization signal sources include earth-based radio transmission (WWV, WWVH, WWVB, and LORAN-C), satellite-based signal transmission (GOES, GPS, and GLONASS), and time-setting messages via communications networks and dial-up modems. All of these timesynchronization signal and time-setting sources can usually be traced back to common or coordinated precision time references operated and provided by government standards organizations. Coordinated Universal Time (UTC) has become the defacto standard time reference for many applications, including most electric power industry applications. This time is now the accepted standard because of its worldwide availability and relatively economical access through GPS satellite clock receivers. This paper focuses on the use of GPS satellites as a synchronized time source and compares and discusses various clocks and clock signal distribution methods to meet electric power industry time-synchronization applications. The other time-synchronization sources mentioned above are discussed in the appendix of this paper for reference purposes.