SNTP对时方式在数字化变电站中应用

Application of SNTP-based time synchronization in digital substation

当前,变电站的对时方式有脉冲对时、编码对时和网络对时3种方式。介绍了某数字化变电站内的简单网络协议(SNTP)同步对时系统,该系统是基于测控装置事故顺序记录分辨率的对时精度测试系统。SNTP对时系统的站控层网络采用传统的双星100M以太网结构,间隔层配置2台RS2100交换机。通过对数字化变电站网络交换机正常负载、重负载、装置CPU负荷高的对时精度测试,分析了影响对时精度的因素主要有:SNTP时间服务器主时钟精度、数字化变电站站控层的网络负载流量、测控装置的CPU利用率及网络设备等的性能。测试结果表明,SNTP对时方式在数字化变电站是一种较好的选择。

The time synchronization modes in digital substation are pulse synchronization, code synchronization and network synchronization. The SNTP（Simple Network Transmission Protocol）-based time synchro- nization system of a digital substation is introduced, which is based on the time synchronization accuracy test system of SOE（Sequence of Events） resolution for the measuring and control device. Its station-level network adopts the 100 M Y-Y Ethernet and its bay-level has two RSG2100 exchangers. The time synchronization accuracy tests for different conditions, such as normal exchanger load, heavy exchanger load and heavy device CPU load show that, the main factors influencing the synchronization accuracy are： the master clock precision of SNTP time server, the communication load of station-level network, the CPU load of measuring and control device and the performance of network equipment. Test result shows that SNTP -based time synchronization system is a better solution for digital substation.