For the disadvantages of analyzing system reliability using common Bayes method,an evaluation method based on improved Bayes-Bootstrap method is presented.Firstly,the data obliteration problem existing in traditional ...For the disadvantages of analyzing system reliability using common Bayes method,an evaluation method based on improved Bayes-Bootstrap method is presented.Firstly,the data obliteration problem existing in traditional Bayes method is analyzed,then an improved sampling arithmetic is proposed on the foundation of an experience function.Finally,effectiveness of this method is proved by an example.The simulating result shows that this method is more accurate than common Bayes method.展开更多
Reliability evaluation of distribution networks under grid-tied and islanded μ grid modes is presented. The Monte Carlo simulation (MCS) algorithm is applied to a modified RBTS Bus 2 distribution network. The network...Reliability evaluation of distribution networks under grid-tied and islanded μ grid modes is presented. The Monte Carlo simulation (MCS) algorithm is applied to a modified RBTS Bus 2 distribution network. The network includes three types of distributed energy resources, namely, solar photovoltaic (PV), wind turbine (WT), and diesel turbine generator (DTG). These distributed generators contribute to supply part of the load during grid-connected mode, but supply 100% of the load in the islanded μ grid mode. A storage system is included to decrease the peak load since the peak of the output power of the PV’s and the peak load do not match time wise in most load profiles. The impact of implementing renewable distributed generation, storage systems, and conventional generation on the reliability of distribution network is studied. This study shows that the penetration of distributed generations can improve the reliability indices of the distribution network.展开更多
The vehicle system studied in this paper is a type of complex repairable system in which the subsystems follow various failure distributions and conform to arbitrary failure and repair distributions.The failure data o...The vehicle system studied in this paper is a type of complex repairable system in which the subsystems follow various failure distributions and conform to arbitrary failure and repair distributions.The failure data of subsystems are sometimes lacking,and the reliability test sample sizes tend to be small.Monte-Carlo technique combined with Bayes method is used to evaluate its dependability(reliability and maintainability).Following the "first-in,first-out" queuing rule,the logic relation of dependability is established by means of repairing priority and event lists.Simulation outputs the entire history of a mission,statistics of reliability and maintainability parameters and provides the basic data for system reliability design and maintainability management.展开更多
The optimal deeision theory and exploitation reliability of large scale mining area have been studied China since the late 1980’s. Researches have been earried out under the thought of mannature - machine system , an...The optimal deeision theory and exploitation reliability of large scale mining area have been studied China since the late 1980’s. Researches have been earried out under the thought of mannature - machine system , and eneouraging results have been obtained. The reliability evaluation of mining engineering ineludes the rellability exaluation of natural resources, mining technology and mine economics ete. And the geological reliability of deposit, as a natural condition, is the basis of all other evaiuation works. The paper summarizes the method for evaluating the geological reliaoility of deposit, diseusces the reliability of estimating methods for coal reserves and coai quality, evaiuates the natural resourees rellability of the Pit 1 of Antaibao Surface Coai Mine, Pingsuo, Shanxi Province.which was taken as a case study.展开更多
Overloads of vehicle may cause damage to bridge structures,and how to assess the safety influence of heavy vehicles crossing the prototype bridge is one of the challenges.In this report,using a large amount of monitor...Overloads of vehicle may cause damage to bridge structures,and how to assess the safety influence of heavy vehicles crossing the prototype bridge is one of the challenges.In this report,using a large amount of monitored data collected from the structural health monitoring system(SHMS)in service of the prototype bridge,of which the bridge type is large-span continuous rigid frame bridge,and adopting FEM simulation technique,we suggested a dynamic reliability assessment method in the report to assess the safety impact of heavy vehicles on the prototype bridge during operation.In the first place,by using the health monitored strain data,of which the selected monitored data time range is before the opening of traffic,the quasi dynamic reliability around the embedded sensor with no traffic load effects is obtained;then,with FEM technology,the FEM simulation model of one main span of the prototype bridge is built by using ANSYS software and then the dynamic reliability when the heavy vehicles crossing the prototype bridge corresponding to the middle-span web plate is comprehensively analyzed and discussed.At last,assuming that the main beam stress state change is in the stage of approximately linear elasticity under heavy vehicle loads impact,the authors got the impact level of heavy vehicles effects on the dynamic reliability of the prototype bridge.Based on a large number of field measured data,the dynamic reliability value calculated by our proposed methodology is more accurate.The method suggested in the paper can do good for not only the traffic management but also the damage analysis of bridges.展开更多
The component aging has become a significant concern worldwide,and the frequent failures pose a serious threat to the reliability of modern power systems.In light of this issue,this paper presents a power system relia...The component aging has become a significant concern worldwide,and the frequent failures pose a serious threat to the reliability of modern power systems.In light of this issue,this paper presents a power system reliability evaluation method based on sequential Monte Carlo simulation(SMCS)to quantify system reliability considering multiple failure modes of components.First,a three-state component reliability model is established to explicitly describe the state transition process of the component subject to both aging failure and random failure modes.In this model,the impact of each failure mode is decoupled and characterized as the combination of two state duration variables,which are separately modeled using specific probability distributions.Subsequently,SMCS is used to integrate the three-state component reliability model for state transition sequence generation and system reliability evaluation.Therefore,various reliability metrics,including the probability of load curtailment(PLC),expected frequency of load curtailment(EFLC),and expected energy not supplied(EENS),can be estimated.To ensure the applicability of the proposed method,Hash table grouping and the maximum feasible load level judgment techniques are jointly adopted to enhance its computational performance.Case studies are conducted on different aging scenarios to illustrate and validate the effectiveness and practicality of the proposed method.展开更多
Integrated energy system(IES)has the advantages of improving the efficiency of energy utilization and promoting the consumption of renewable energy.It is of great importance to evaluate the reliability of an IES.This ...Integrated energy system(IES)has the advantages of improving the efficiency of energy utilization and promoting the consumption of renewable energy.It is of great importance to evaluate the reliability of an IES.This paper proposes a novel reliability evaluation method for the electricity-heat IES with heat pump.First,the load-point reliability indices and systemlevel reliability indices are defined according to the characteristics of electricity-heat IES.Second,the model of maximum output heat power of heat pump at the user-side considering the safety criterion of distribution network is established,and the stepvaried repeated power flow method is applied to solve the model.Third,the reliability evaluation procedure of electricityheat IES with heat pump based on the Monte Carlo simulation is presented.Case studies are carried out on the electricityheat IES of an industrial park,and the results show that the configuration site,capacity and coefficient of performance of heat pump as well as the security constraints of distribution network can significantly affect the reliability indices.展开更多
基于失效物理(Physics of Failure,PoF)分析方法,提出了规范化的系统级封装(System in Package,SiP)产品的可靠性评价标准。完成了国内外基于失效物理的SiP可靠性评价方法的适用性分析,并利用计算机仿真技术和手段设计了包含模型构建、...基于失效物理(Physics of Failure,PoF)分析方法,提出了规范化的系统级封装(System in Package,SiP)产品的可靠性评价标准。完成了国内外基于失效物理的SiP可靠性评价方法的适用性分析,并利用计算机仿真技术和手段设计了包含模型构建、应力剖面分析、可靠性预计与寿命预测等在内的SiP可靠性评价总体方案,给出了基于失效物理的SiP可靠性评价标准中的核心内容,包括评价流程、工作内容及详细要求等。还探讨了评价方案在某型SiP实际产品中的应用情况,表明该方案有效性强且工程适用,与基于加速寿命试验的产品可靠性评价结果吻合度较高,研究成果有助于解决当期SiP可靠性评价缺乏统一有效方法、评价针对性差、寿命试验周期长、缺乏失效数据、试验成本高等难题。展开更多
The research on reliability evaluation of an integrated energy system(IES)is of great significance to system planning and operations.The differences of multiple energy subsystems must be considered in reliability eval...The research on reliability evaluation of an integrated energy system(IES)is of great significance to system planning and operations.The differences of multiple energy subsystems must be considered in reliability evaluation of an IES,in which energy quality differences of various energy resources is critical.Current reliability evaluation of an IES cannot uniformly evaluate the reliability of multiple energy subsystems due to neglecting the energy quality differences of various energy resources.To address this problem,a novel reliability evaluation method for IESs based on exergy is proposed for the first time in this paper.The exergy of an energy resource or a substance is a measure of its usefulness,quality or potential to cause change.The models of exergy not supplied minimization and exergy efficiency maximization are proposed to alleviate energy capacity deficiency and transmission component overload in the reliability evaluation of an IES.These two models are compared to analyze exergy efficiency for the proposed method.The energy supply priority strategy of an IES is proposed considering energy quality differences of various energy resources,in which electricity,gas and heating/cooling subsystems are supplied in an orderly manner.Furthermore,a reliability evaluation indices system of an IES based on exergy is proposed in this paper.An extensive case study on an actual IES demonstrates the feasibility and effectiveness of the proposed reliability evaluation method.展开更多
This paper intends to study the stochastic response and reliability of the roll motion under the action of wind and wave excitation.The roll motion in random beam seas is described by a four-dimensional(4D)Markov dyna...This paper intends to study the stochastic response and reliability of the roll motion under the action of wind and wave excitation.The roll motion in random beam seas is described by a four-dimensional(4D)Markov dynamic system whose probabilistic properties are governed by the Fokker-Planck(FP)equation.The 4D path integration(PI)method,an efficient numerical technique based on the Markov property of the 4D system,is applied in order to solve the high dimensional FP equation and then the stochastic statistics of the roll motion are derived.Based on the obtained response statistics,the reliability evaluation of the ship stability is performed and the effect of wind action is studied.The accuracy of the 4D PI method and the reliability evaluation is assessed by the versatile Monte Carlo simulation(MCS)method.展开更多
系统状态随机抽样是大电网可靠性蒙特卡洛仿真的重要基础环节,抽取的样本容量与仿真结果的精度和仿真耗时密切相关,因此在给定仿真精度时实现样本容量的概率预估和在给定样本容量时实现计算精度的概率预测,是实现计算精度和计算成本综...系统状态随机抽样是大电网可靠性蒙特卡洛仿真的重要基础环节,抽取的样本容量与仿真结果的精度和仿真耗时密切相关,因此在给定仿真精度时实现样本容量的概率预估和在给定样本容量时实现计算精度的概率预测,是实现计算精度和计算成本综合权衡的关键。基于中心极限定理深入研究随机变量的样本均值与期望值之间误差的概率预测方法,在此基础上分析失负荷概率(loss of load probability,LOLP)指标的方差系数和样本容量之间的关系表达式,导出方差系数给定时的样本容量置信区间公式及样本容量给定时的方差系数置信区间公式。这些公式的导出,对于实现仿真精度和样本容量之间的定量概率分析具有重要意义,通过对RBTS和RTS96可靠性测试系统的评估分析验证所提方法的有效性和正确性,并得出相关结论。展开更多
文摘For the disadvantages of analyzing system reliability using common Bayes method,an evaluation method based on improved Bayes-Bootstrap method is presented.Firstly,the data obliteration problem existing in traditional Bayes method is analyzed,then an improved sampling arithmetic is proposed on the foundation of an experience function.Finally,effectiveness of this method is proved by an example.The simulating result shows that this method is more accurate than common Bayes method.
文摘Reliability evaluation of distribution networks under grid-tied and islanded μ grid modes is presented. The Monte Carlo simulation (MCS) algorithm is applied to a modified RBTS Bus 2 distribution network. The network includes three types of distributed energy resources, namely, solar photovoltaic (PV), wind turbine (WT), and diesel turbine generator (DTG). These distributed generators contribute to supply part of the load during grid-connected mode, but supply 100% of the load in the islanded μ grid mode. A storage system is included to decrease the peak load since the peak of the output power of the PV’s and the peak load do not match time wise in most load profiles. The impact of implementing renewable distributed generation, storage systems, and conventional generation on the reliability of distribution network is studied. This study shows that the penetration of distributed generations can improve the reliability indices of the distribution network.
基金Sponsored by National Post Doctor Science Foundation of China (2003033180)
文摘The vehicle system studied in this paper is a type of complex repairable system in which the subsystems follow various failure distributions and conform to arbitrary failure and repair distributions.The failure data of subsystems are sometimes lacking,and the reliability test sample sizes tend to be small.Monte-Carlo technique combined with Bayes method is used to evaluate its dependability(reliability and maintainability).Following the "first-in,first-out" queuing rule,the logic relation of dependability is established by means of repairing priority and event lists.Simulation outputs the entire history of a mission,statistics of reliability and maintainability parameters and provides the basic data for system reliability design and maintainability management.
文摘The optimal deeision theory and exploitation reliability of large scale mining area have been studied China since the late 1980’s. Researches have been earried out under the thought of mannature - machine system , and eneouraging results have been obtained. The reliability evaluation of mining engineering ineludes the rellability exaluation of natural resources, mining technology and mine economics ete. And the geological reliability of deposit, as a natural condition, is the basis of all other evaiuation works. The paper summarizes the method for evaluating the geological reliaoility of deposit, diseusces the reliability of estimating methods for coal reserves and coai quality, evaiuates the natural resourees rellability of the Pit 1 of Antaibao Surface Coai Mine, Pingsuo, Shanxi Province.which was taken as a case study.
文摘Overloads of vehicle may cause damage to bridge structures,and how to assess the safety influence of heavy vehicles crossing the prototype bridge is one of the challenges.In this report,using a large amount of monitored data collected from the structural health monitoring system(SHMS)in service of the prototype bridge,of which the bridge type is large-span continuous rigid frame bridge,and adopting FEM simulation technique,we suggested a dynamic reliability assessment method in the report to assess the safety impact of heavy vehicles on the prototype bridge during operation.In the first place,by using the health monitored strain data,of which the selected monitored data time range is before the opening of traffic,the quasi dynamic reliability around the embedded sensor with no traffic load effects is obtained;then,with FEM technology,the FEM simulation model of one main span of the prototype bridge is built by using ANSYS software and then the dynamic reliability when the heavy vehicles crossing the prototype bridge corresponding to the middle-span web plate is comprehensively analyzed and discussed.At last,assuming that the main beam stress state change is in the stage of approximately linear elasticity under heavy vehicle loads impact,the authors got the impact level of heavy vehicles effects on the dynamic reliability of the prototype bridge.Based on a large number of field measured data,the dynamic reliability value calculated by our proposed methodology is more accurate.The method suggested in the paper can do good for not only the traffic management but also the damage analysis of bridges.
基金supported by the National Natural Science Foundation of China(No.52022016)the Fundamental Research Funds for the Central Universities(No.2023CDJYXTD-004)the Graduate Research and Innovation Foundation of Chongqing(No.CYB22014)。
文摘The component aging has become a significant concern worldwide,and the frequent failures pose a serious threat to the reliability of modern power systems.In light of this issue,this paper presents a power system reliability evaluation method based on sequential Monte Carlo simulation(SMCS)to quantify system reliability considering multiple failure modes of components.First,a three-state component reliability model is established to explicitly describe the state transition process of the component subject to both aging failure and random failure modes.In this model,the impact of each failure mode is decoupled and characterized as the combination of two state duration variables,which are separately modeled using specific probability distributions.Subsequently,SMCS is used to integrate the three-state component reliability model for state transition sequence generation and system reliability evaluation.Therefore,various reliability metrics,including the probability of load curtailment(PLC),expected frequency of load curtailment(EFLC),and expected energy not supplied(EENS),can be estimated.To ensure the applicability of the proposed method,Hash table grouping and the maximum feasible load level judgment techniques are jointly adopted to enhance its computational performance.Case studies are conducted on different aging scenarios to illustrate and validate the effectiveness and practicality of the proposed method.
基金This study was supported in part by the Shanghai Sailing Program(No.18YF1411600)the National Key R&D Program of China(No.2018YFB0905000).
文摘Integrated energy system(IES)has the advantages of improving the efficiency of energy utilization and promoting the consumption of renewable energy.It is of great importance to evaluate the reliability of an IES.This paper proposes a novel reliability evaluation method for the electricity-heat IES with heat pump.First,the load-point reliability indices and systemlevel reliability indices are defined according to the characteristics of electricity-heat IES.Second,the model of maximum output heat power of heat pump at the user-side considering the safety criterion of distribution network is established,and the stepvaried repeated power flow method is applied to solve the model.Third,the reliability evaluation procedure of electricityheat IES with heat pump based on the Monte Carlo simulation is presented.Case studies are carried out on the electricityheat IES of an industrial park,and the results show that the configuration site,capacity and coefficient of performance of heat pump as well as the security constraints of distribution network can significantly affect the reliability indices.
文摘基于失效物理(Physics of Failure,PoF)分析方法,提出了规范化的系统级封装(System in Package,SiP)产品的可靠性评价标准。完成了国内外基于失效物理的SiP可靠性评价方法的适用性分析,并利用计算机仿真技术和手段设计了包含模型构建、应力剖面分析、可靠性预计与寿命预测等在内的SiP可靠性评价总体方案,给出了基于失效物理的SiP可靠性评价标准中的核心内容,包括评价流程、工作内容及详细要求等。还探讨了评价方案在某型SiP实际产品中的应用情况,表明该方案有效性强且工程适用,与基于加速寿命试验的产品可靠性评价结果吻合度较高,研究成果有助于解决当期SiP可靠性评价缺乏统一有效方法、评价针对性差、寿命试验周期长、缺乏失效数据、试验成本高等难题。
基金supported in part by the National Natural Science Foundation of China under Grant No.51637008 and No.U1610122.
文摘The research on reliability evaluation of an integrated energy system(IES)is of great significance to system planning and operations.The differences of multiple energy subsystems must be considered in reliability evaluation of an IES,in which energy quality differences of various energy resources is critical.Current reliability evaluation of an IES cannot uniformly evaluate the reliability of multiple energy subsystems due to neglecting the energy quality differences of various energy resources.To address this problem,a novel reliability evaluation method for IESs based on exergy is proposed for the first time in this paper.The exergy of an energy resource or a substance is a measure of its usefulness,quality or potential to cause change.The models of exergy not supplied minimization and exergy efficiency maximization are proposed to alleviate energy capacity deficiency and transmission component overload in the reliability evaluation of an IES.These two models are compared to analyze exergy efficiency for the proposed method.The energy supply priority strategy of an IES is proposed considering energy quality differences of various energy resources,in which electricity,gas and heating/cooling subsystems are supplied in an orderly manner.Furthermore,a reliability evaluation indices system of an IES based on exergy is proposed in this paper.An extensive case study on an actual IES demonstrates the feasibility and effectiveness of the proposed reliability evaluation method.
文摘This paper intends to study the stochastic response and reliability of the roll motion under the action of wind and wave excitation.The roll motion in random beam seas is described by a four-dimensional(4D)Markov dynamic system whose probabilistic properties are governed by the Fokker-Planck(FP)equation.The 4D path integration(PI)method,an efficient numerical technique based on the Markov property of the 4D system,is applied in order to solve the high dimensional FP equation and then the stochastic statistics of the roll motion are derived.Based on the obtained response statistics,the reliability evaluation of the ship stability is performed and the effect of wind action is studied.The accuracy of the 4D PI method and the reliability evaluation is assessed by the versatile Monte Carlo simulation(MCS)method.
文摘系统状态随机抽样是大电网可靠性蒙特卡洛仿真的重要基础环节,抽取的样本容量与仿真结果的精度和仿真耗时密切相关,因此在给定仿真精度时实现样本容量的概率预估和在给定样本容量时实现计算精度的概率预测,是实现计算精度和计算成本综合权衡的关键。基于中心极限定理深入研究随机变量的样本均值与期望值之间误差的概率预测方法,在此基础上分析失负荷概率(loss of load probability,LOLP)指标的方差系数和样本容量之间的关系表达式,导出方差系数给定时的样本容量置信区间公式及样本容量给定时的方差系数置信区间公式。这些公式的导出,对于实现仿真精度和样本容量之间的定量概率分析具有重要意义,通过对RBTS和RTS96可靠性测试系统的评估分析验证所提方法的有效性和正确性,并得出相关结论。
