作者：赵颖（福建福清核电有限公司，福建 福州 350300）

摘要：福清核电全厂时钟系统作为电厂的授时母钟，为涉网电气系统、全厂DCS系统、汽轮机P320控制系统等重要电气、仪控自动控制设备提供时钟基准信号授时，其可靠性对电厂自动控制系统的安全稳定运行有着重要的意义。本文以福清核电时钟系统为主线，介绍福清核电1~4号机组时钟系统结构，时钟系统投用后，先后多次由于时钟信号错误导致DCS控制系统二层出现不同程度故障事件，根据运行技术规范要求，机组被迫由KIC模式切换到BUP模式运行，甚至降功率运行，严重危及机组的安全。通过对事件原因进行深入分析研究，找出时钟设备、系统固有缺陷，提出优化改进措施，提高时钟系统运行可靠性。针对“华龙一号”5/6号机组的时钟系统，系统在供电、检测控制模块、校时、时钟检测等方面均有较大提升与改进，以保证对控制系统授时可靠性。最后对福清核电全厂的时钟系统进行期望性的规划，其可为各系统提供最精准的时钟基准信号，保障机组安全稳定运行，为后续核电机组设计、调试、运维提供重要参考经验。

关键词：时钟；可靠性；DCS

Abstract: Fuqing Nuclear Power Plant's clock system is used as the master clock for power plants. It provides clock reference signals for important electrical and instrumentation automatic control equipment such as network-related electrical systems, plant-wide DCS systems,and turbine P320 control systems. The safe and stable operation of the system is of great significance. Based on Fuqing nuclear power clock system as the main line, this paper introduces clock system structure of Fuqing nuclear power unit 1-4. After the clock system is putting-in-service proactively, multiple levels of fault events occur in the second layer of the DCS control system due to clock signal errors.According to the operating technical specifications It is required that the unit be forced to switch from KIC mode to BUP mode and even run at reduced power, which seriously endangers the safety of the unit.Through in-depth analysis and research on the causes of the event,the inherent defects of the clock equipment and system are found out,and optimization and improvement measures are proposed to improve the operating reliability of the clock system. As for the clock system of “Hualong No.1” unit 5/6 in the power supply, control module, the school, the clock have significant improvement to ensure the reliability of timing control system. Finally, the clock system of the entire Fuqing nuclear power plant is expected to be planned, which can be for the system to provide the most accurate clock reference signal, guarantee the safe and stable operation of unit, and provide important reference experience for subsequent nuclear power units provide a valuable reference for design, commissioning, operation and maintenance..

Key words: The clock; Reliability; DCS

在线预览：福清核电时钟系统可靠性研究与提升

摘自《自动化博览》2019年12月刊