混合组网下采样值传输时延值测量的可信度评估

Credibility Evaluation of Time Delay Measurement of Transmission for Sample Value in Mixed Network

智能变电站保护装置网络采样、网络跳闸应用中模拟量采样值(SV)传输时延的确定性和准确度是系统安全可靠运行的关键因素。一种基于报文实现SV数据传输时延实时测量及补偿的方法逐渐被接受,开始应用于智能站"三网共口"和就地化保护专网等场合。文中介绍了混合组网下SV报文传输时延测量方法和实现,详细分析了该方法在实现传输时延准确测量各个环节的可信度及其影响,并对报文中与SV数据强关联的时延测量值提出了基于总链路时延合理值和总链路时延误差值作为指标组合来进行在线评估的方法,详细阐述了其工程阈值的取值方法。最后,文中通过选取就地化保护专网的专项测试分析与实际应用,验证了该方案的有效性和可靠性。

The certainty and accuracy of transmission time delay of analog sample value(SV) in network sampling and tripping are key factors for the reliable operation of the system in smart substation. A real-time measurement and compensation method for transmission delay of realizing SV data transmission based on message is gradually accepted by the majority, and applied to the 3-in-1 network in smart substation and dedicated network for outdoor installation protections. In this paper, the principle and implementation of the time delay measurement method for SV message transmission are described first, the credibility and its influence of proposed method in related parts of realizing accurate measurement of transmission delay are analyzed in detail. Then, an online credibility evaluation method based on the combination values of the total link delay and the total link delay error is proposed according to the delay measurements for strong correlation between messages and SV data and how to select the value of engineering threshold is put forward. At last, the effectiveness and reliability of the scheme are verified by selecting the special test analysis and practical application of outdoor protection dedicated network.