DCS一、二层接口防IIC失效风险的研究

Study of IIC Failure Risk Prevention for Layer 1 and Layer 2 Interfaces of DCS

核电站全厂控制系统广泛采用数字化的分布式控制系统(DCS)。一层为控制柜及供电、网络等设备。二层是以计算机信息和控制系统(系统代码为IIC)为主、后备盘(BUP)为辅的人机接口设备。一层担负着核电站的实时控制,是完整、独立的控制系统,其自动控制、保护等功能不依赖于二层。为防止因IIC失效给电厂运行造成风险,提出了一、二层接口设计的改进方法:一层接收二层的脉冲指令,防止二层失效对一层现有状态造成影响;一层逻辑中能闭锁IIC指令,防止BUP控制模式下IIC发出无效指令;增加选择开关KC模块的输入参数,将一层的当前模式上送IIC显示,防止发出错误指令或造成操作员误判。该研究为核电或其他工业控制系统一、二层接口设计提供了借鉴和参考。

Digital distributed control system(DCS)is widely used in the plant-wide control system of nuclear power plants.Layer 1 is the control cabinet and power supply,network,and other equipment.Layer 2 is a human-machine interface equipment with computer information and control system(system code is IIC)as the main and backup panel(BUP)as the supplement.Layer 1 is responsible for the real-time control of the nuclear power plant and is a complete,independent control system whose automatic control,protection and other functions do not depend on layer 2.In order to prevent risks to plant operation due to IIC failure,an improved method of interface design between the layer 1 and layer 2 is proposed:the layer 1 receives pulse commands from layer 2 to prevent layer 2 from failing to affect the existing state of the first layer;layer 1 logic can block IIC commands to prevent the IIC from issuing invalid commands in the BUP control mode;the input parameters of the KC module of the selection switch are added to send the current mode of layer 1 up to the IIC for display.The IIC can also be used to prevent wrong commands or operator misjudgments.The study provides a reference for the design of interfaces of the layer 1 and layer 2 for nuclear power or other industrial control systems.