CPR1000核电厂核级DCS平台缺省值实现方案研究

针对CPR1000核电厂核级DCS无平台功能实现缺省值问题,对MELTAC DCS平台的信号失效诊断机制进行了分析,对信号质量位传递管理进行了研究,并考虑避免缺省值输出抖动,确定了缺省值替换逻辑方案。同时针对工程实施中CPU负荷超标风险对缺省值实现方案进行了调整,将缺省值替换逻辑实现位置由信号输入机柜转移到控制指令的输出机柜或非安全级DCS网关。最终获得了信号失效诊断、信号质量位传递管理、缺省值替换配合实现缺省值功能的方案。将该方案在多项目进行了试验及应用。结果表明,缺省值实现方案能够在预期信号故障情况下实现缺省值无抖动输出,并且未造成CPU负荷超标。

Default value realization research of CPR1O00 safety classified DCS platform

Aiming at the problems of the safety DCS used in CPR1000 nuclear power plants had no platform function of default value,the signal fault self-diagnosis mechanism of MELTAC DCS platform was analyzed,signal quality transmitting management was researched,and default value switchover was established as a counter-measure to output disturbing.Meanwhile,because the risk of CPU over load,the scheme was adjusted,the default value realization location was changed from signal input cabinet to command output cabinet or NC DCS gateway.Finally,the scheme base on corporation of signal unavailable diagnosing,signal quality transmitting management and default value switchover was established.The scheme was tested and implemented in multi-projects.The results show that the default value scheme can avoid risk of CPU overload and meanwhile fulfill the requirement of default value function.