The minimal path sets and the minimal cut sets are the key tools to evaluate the network reliability , which divide the system states into two : success ( s = 1 ) and failure ( s = 0 ) 网络的最小路集和最小割集分别从成功( s = 1 )和失败( s = 0 )的不同角度描述了网络的不同状态,是网络可靠度求解的关键。
The assessment method integrates the series equivalent approach and minimal cut - set to evaluate the reliability of electrical distribution net which consists of mid - voltage and low - voitage net on the assumption that there are sufficient and accurate datum 评估计算中,假设所获得的数据和资料充足、准确,采用串联等值法与最小割集法结合,进行包括中、低压的供电网络的可靠性评估。
After then , a new method of solving the minimal cuts of s - coherent tree based on bdd and prime number was given in the qualitative analysis of fta based on bdd , the prime implicant sets of non s - coherent tree was calculated by an iterative method 再次,在基于bdd的故障树定性分析研究中,提出并实现了基于bdd和素数法相结合的单调关联故障树最小割集求解的新方法,用迭代法实现了非单调关联故障树质蕴含的求解。
This thesis focuses on techniques of dynamic fault tree in system reliability modeling and its qualitative and quantitative analysis . it studies bdd solution for static sub trees 、 markov chain solution for dynamic sub tree briefly and the modularization of dynamic fault tree ; presents the algorithm for top event occurrence rate of dynamic fault tree based on weibull distribution . then this thesis presents a new approach to solve top event occurrence rate and a new generation algorithm of minimal cut sequence of dynamic fault tree that deviate from markov model completely 本文着眼于动态故障树在系统可靠性建模及定性定量分析中的技术,研究了基于bdd的静态子树分析方法、基于马尔可夫模型的动态子树分析方法以及动态故障树模块化方法,并提出了基于威布尔分布的动态故障树顶事件发生概率计算方法;提出了一种完全脱离马尔可夫模型的求解动态故障树顶事件发生概率的方法和一种最小顺序割集的生成方法。
A lot of papers about the report of probabilistic risk assessment of daya bay npp and system manuals has been read by the author and let as the basis . in this paper , based on the reliability analysis methods of failure mode and effect analysis and failure tree analysis , according to the result of event tree analysis of probabilistic risk assessment report of daya bay npp , the top events of the fault trees of reactor protection system and the success criteria were established . by using risk - spectrum procedure , the unavailability and the minimal cut - sets ( mcs ) of the fault trees were obtained 本文在阅读了大量的大亚湾核电站pra报告和各种系统手册等资料的基础上,采用fmea (故障模式和影响分析)和fta (故障树分析)可靠性分析方法,依据大亚湾核电站pra事件树分析的结果,建立了以紧急停堆失效和专设安全设施驱动失效为顶事件的故障树,利用risk - spectrum程序,对所建的故障树进行定量分析,计算,得到系统故障树的失效概率和最小割集,从而为大亚湾核电站可视化风险分析软件提供数据支持。
Many practical factors , such as effects of line fuses protection , disconnected switches , scheduled maintenance , spare electrical source , spare transformers in distribution system , are considered in the assessment arithmetic . in the assessment , it is more practical that low - voltage power system is equivalent to an element on the lateral section of mid - voltage system . especially , the minimal cut - sets are divided into direct cuts and indirect cuts , which makes the effects of elements in cuts on system more legible and exact 算法考虑了分支线熔断器保护、隔离开关、计划检修、备用电源、有无备用变压器的影响,将低压系统等效为中压系统分支馈线上的一个等效元件进行评估,使得该方法更符合实际,特别是,将最小割集分为直接割集和间接割集,使割集元件的影响更加清晰准确,并以c + +语言编制了计算软件。
Based on research of theory and methods , this thesis presents design scheme of the dynamic fault tree analysis platform dfta and implement the platform ; practices a dynamic fault tree analysis example of boeing 707 plane engine oil indication system and alarm system on the platform and gets top event occurrence rate 、 minimal cut sequence 、 probability importance sequence 、 structure importance sequence and critical importance sequence and presents system improvement suggestion based on the analysis results 在理论方法研究的基础上,本文提出了动态故障树分析平台dfta的设计方案,并进行了实现;利用该软件对波音707飞机发动机滑油压力指示和警告系统进行了动态故障树实例分析,得到了顶事件发生概率、最小顺序割集、概率重要度排序、结构重要度排序、关键重要度排序等分析结果,并根据上述分析结果提出了系统设计改进建议。
By analyzing the topology of an interconnected power system , chapter 3 of this thesis derives the spanning tree , and builds the corresponding minimal cut set . by combining the results from the graph theory with the reliability indices of the individual reparable components , the reliability indices at the load point can be obtained , and the reliability indices for the whole system are deduced 本文的第三章从单个可修复元件的可靠性指标出发,在分析电网络的拓扑结构的基础上,利用一定的算法求出其对应的生成树,根据生成树和最小割集之间的对应关系,得到整个电网络的最小割集。
Firstly , reliability models of different element are built in the paper . secondly , the reliability parameters of virtual series element on the main feeders are computed by series equivalent method . lastly , indices of different load points are calculated by the method of minimal cut - set 文中首先建立了不同元件的可靠性模型,其次通过串联等值法求取各主馈线上的虚拟串联等值元件的可靠性参数,最后应用最小割集方法计算各负荷点指标,从而得到系统各项可靠性指标。
At last , we developed a system of life forecasting and risk assessment using powerbuilder7 . 0 . the system can calculate the reliability , mtbf and forecast the reliable lifetime . so it gives a basis for design and decision ; moreover , the system can determine whether repair is difficult or easy , is economic or not , is effective or not ; thirdly , the system can draw fta and eta , get the minimal cut - assembly , calculate quantitativly , analysis the result of breakdown 该系统可以计算可靠度、 mtbf ,实现可靠性寿命预测的功能,为设计和决策提供基础;同时可以评估维修的难易程度、经济性和有效性的合理性;而且可以进行故障树的绘制、事件树的绘制、求最小割集、定量计算以及故船舶动力装置寿命预测与风险评估障的后果分析。