分层概率符号有向图在热力系统故障诊断中的应用  

Application of hierarchical probability signed directed graph in thermal system

作　　者：杨蕊[1] 谢刚[1] 陈泽华[1] 李勇伟[1] 赵鹏 

机构地区：[1]太原理工大学信息工程学院,山西太原030024 [2]阳城国际发电有限责任公司,山西晋城048102

出　　处：《热力发电》2014年第9期137-141,共5页Thermal Power Generation

基　　金：国家自然科学基金(60975032);山西省青年科技研究基金(2009021017-4);山西省留学回国人员科技活动择优资助项目(2013-68;2013-69;2011-172)

摘　　要：复杂热力系统的传统符号有向图(SDG)模型结构复杂,诊断时搜索路径易产生"组合爆炸"和难于区分多故障源等问题,对此提出了基于分层概率的SDG模型,利用分层简化搜索路径,采用定性和定量相结合的方法描述故障之间的因果关系;基于分层概率SDG的故障诊断方法,通过建立系统的分层有向图模型减少搜索空间,利用相容性和贝叶斯推理进行诊断,得到各故障源的概率及可能性排序。将该方法应用于某300MW机组高压加热器给水系统的故障诊断,其在提高故障源分辨率的同时减少了搜索空间,避免了"组合爆炸"的发生。Due to the complicated structure of conventional signed directed graph（SDG）model of complex thermal system,problems like combinatorial explosion in search paths and difficulty in distinguishing multiple fault sources occur easily during the diagnosis.Thus,the hierarchical probability signed directed graph（SDG）model was proposed,which uses the layered method to simplify the search paths and describes the causal relationship between failures by applying a combination method of qualitative and quantitative method.Moreover,a new fault diagnosis method based on the hierarchical probabilistic signed directed graph was put forward.This method takes advantage of the established SDG model to reduce the search space first,and then employs the compatibility and Bayesian inference to diagnose the faults,at last,it calculates the probability of failure and possible sequence of the source.Finally,this method was applied in failure diagnosis of high pressure heater system of a 300 MW unit.The results show that,this method not only improves the fault source resolution but also reduces the search space,which avoids the ＂combinatorial explosion＂.

关 键 词：热力系统 故障诊断 符号有向图 贝叶斯推理 分层概率 相容通路 

分 类 号：TP206.3[自动化与计算机技术—检测技术与自动化装置]