分散控制系统模拟量输出模件的安全评估  

Safety Assessment of DCS Analog Output Modules

作　　者：王鹏[1] 白焰[1] 付亚利[1] 

机构地区：[1]华北电力大学控制与计算机工程学院,北京102206

出　　处：《化工自动化及仪表》2014年第6期680-683,共4页Control and Instruments in Chemical Industry

摘　　要：以目前实际应用的模拟量输出(AO)模件LN-05B为基础,根据IEC61508和IEC61511标准框架,应用最常用的功能安全评估技术之一(故障树的最小割集不交化方法)定量、保守地评估了AO的可靠性与安全性。首先综合考虑共因失效和诊断两个重要影响因素,构建了危险失效故障树;其次利用下行法得到故障树的最小割集;再次搜集部件失效概率数据,应用最小割集不交化方法计算出要求时失效概率;最后确定安全完整性等级并总结了这种可靠性分析方法的优势与不足。Basing on LN-05B analog output module and according to IEC 61508 and IEC61511 standards,the commonly-used functional safety assessment techniques（ fault tree minimal cut sets method） were employed to assess AO＇s safety and reliability quantitatively and conservatively,in which,having the common cause failure and diagnosis comprehensively considered to construct a fault tree for the dangerous failure; and having top-down way employed to get fault tree＇s minimum cut sets and then having the component failure rates collected to calculate probability of the failure on demand（ PFD） through the minimal cut sets method,and finally,having the safety integrity level（ SIL） determined and both advantages and disadvantages of this analysis method discussed.

关 键 词：模拟量输出模件 安全完整性等级 故障树 可靠性 要求时失效概率 最小割集 

分 类 号：TH165.2[机械工程—机械制造及自动化]