基于ADACS_N平台的DCS二层时钟处理机制研究与改进

Time Signal Processing Analysis and Improvement for DCS Level 2 System Based on ADACS_N Platform

核电厂数字化集散控制系统(DCS)对比传统的模拟盘台控制方式,对时钟信号的处理提出了更高要求。DCS二层作为信息监视与操作控制层,负责处理DCS一二层实时数据并将处理结果送往人机交互界面显示。DCS二层对时钟信号的处理主要包含系统时钟同步以及一二层实时数据时标处理。以现场问题为导向,研究DCS二层时钟同步机制、时钟监测报警机制、实时数据时标解析机制以及实时数据时标过滤机制中存在的不合理因素,结合日志代码分析以及模拟测试等方式,找出DCS二层时钟处理机制中存在的整点强制重启网络时钟协议(NTP)进行时间同步、时钟同步报警监测机制需优化、实时数据解析时可能误改写一层数据时标以及实时数据过滤机制不合理可能导致DCS一二层状态不一致等问题,并逐一进行优化解决,以确保DCS二层时钟机制有效、DCS二层系统正确可靠运行。

Digital distributed control system of nuclear power plant puts forward higher requirements for time signal processing than conventional mosaic disk control mode.As an information monitoring and operation control system,the DCS level 2 is responsible for processing real-time data of the DCS level 1 and level 2 interfaces and displaying the processing results on the human monitoring interface.The processing of time signal in DCS level 2 includes system clock synchronization and processing of real-time data time of the DCS level1 and level 2 interfaces.Based on the research of time synchronization mechanism,time synchronization monitoring and alarm mechanism,real-time data timestamp analysis resolution mechanism and real-time data timestamp filtering mechanism in DCS level 2,the time signal processing mechanism is studied by dealing with the site issues,and combined with log code analysis and simulation test,some issues with the mechanism are observed,such as the restart of network clock protocol on the hour,the time synchronization monitoring and alarm mechanism needing to be optimized,real-time data timestamp overwrite,and unreasonable real-time data filtering mechanism which may lead to a discrepancy in DCS level 1 and level 2.Finally,these mentioned issues on time processing mechanism is optimized one by one to ensure the effectiveness of DCS level 2 time processing mechanism,which makes DCS level 2 runs reliably.