热备架构的冗余AO模块设计

Redundancy Analog Output Module Design on Hot Standby Framework

模拟量输出(AO)模块作为分布式控制系统(DCS)平台的重要组成部分,能够实现工业控制4~20 mA的标准电流信号输出,参与反应堆的控制和保护.DCS平台热备架构针对控制器实现主从热备,提高了主控制器模块(MPU)的可靠性,但未考虑AO信号的冗余.设计采用半值均流的方法,利用冗余AO模块之间直接的状态交互,实现故障情况下输出通道的快速切换,达到信号输出'无扰'.对冗余AO模块设计的必要性进行探讨,结合非冗余模型分析故障类型,提出冗余设计方案,阐述故障处理机制,并通过测试验证了设计的可行性.

As an important part of distributed control system(DCS)platform,analog output(AO)module can realize an output of 4—20 mA current signal for industrial control and participate in reactor control and protection.The hot standby architecture of DCS platform implements master-slave hot standby for the controller,which improves the reliability of main process unit(MPU),but the redundancy of AO signals is not considered.In this design,the half-value current sharing method is adopted,and the direct state interaction among the redundant AO modules is used to realize the fast switching of the output channel under the condition of fault,so as to achieve the signal output without disturbance.This paper discusses the necessity of redundant AO module design,introduces the non-redundant model fault types,proposes the redundant design scheme,expounds the fault handing mechanism,and verifies the feasibility of the design through testing.