提高600 MW超临界机组联锁保护信号源可靠性分析与实践

600 MW超临界机组分散控制系统(DCS)联锁保护的信号源在初始设计中采用了以开关量为主的一次逻辑元件,经长时间运行后,现场环境对一次逻辑元件影响较大,很可能产生保护误动或拒动。在机组调试阶段,对机组联锁保护信号源可靠性进行了分析研究并作了二次设计,利用模拟量测量系统丰富冗余的数据采集测点,通过数字逻辑组态有机整合成防误动拒动、可靠性很高的信号源,提高了联锁保护的可靠性。在进行联锁保护的数字逻辑冗余的二次设计中,应注意逻辑设计合理、数字逻辑优化,要解决好电气与顺序控制系统(SCS)之间的接口问题,防止干扰信号造成误动等。

Analysis and practice on the reliability improvement of interlock protection signal resource for 600 MW supercritical unit

The primary logic element was utilized in the preliminary design of interlock protection signal resource in the DCS system of 600 MW supercritical unit. After long term operation, the primary logic element was much impacted by the environment on site, resulting in the misoperation or refused-operation to some extent. During the commissioning of unit, the reliability of interlock protection signal resource was analyzed and redesigned. Using abundant and redundant date acquisition measurements of analog signal, the signal resource with high reliability was integrate by means of digital logic configuration to avoid the misoperation or refused-operation and improve the reliability of interlock effectively. In the second redundant digital logic design of interlock protection it is required to pay attention to the reasonable logic design and digital logic optimization so as to solve the interface problems between SCS and electric system and prevent the misoperation caused by disturbances.