The reliability of key components of urban rail transit (URT) plays an important role in the maintenance plans of URT. It is necessary to establish the reliability model of URT trains. In the current research, the reliability model has a limited scope of application and fails to accurately depict the reliability of key components in URT trains. To solve the above problem, a multi-peak type mixture Weibull distribution model is established using several three-parameter Weibull distributions based on fault modes of components sourced from historical lifetime data. Due to the complexity of this model, parameter estimation is challenging. For this purpose, an improved hunter-prey optimization (IHPO) was proposed to improve parameter estimation accuracy. Firstly, an improved Hénon chaos map was introduced to improve the distribution of the initial population. Secondly, the Lévy flight was introduced to increase the probability of the individual spreading to the whole range at the late stage. Lastly, a nonlinear balance factor was proposed to enhance the algorithm’s global search capability. The simulation experiment was carried out with examples of the balanced pressing wheel and the wheelset. The IHPO algorithm-based parameter estimation method shows the highest R-square with values of 0.996 and 0.999, respectively, and the lowest root mean square error with values of 0.019 and 0.008, respectively. The simulation results demonstrate that the stability and optimization of the HPO are improved, and the multi-peak mixture Weibull distribution model based on the IHPO can accurately depict URT trains’ reliability.
{"title":"Reliability model for key components of urban rail transit train based on improved hunter-prey optimization","authors":"Jiecheng Zhong, Deqiang He, Zhenzhen Jin, Haimeng Sun, Sheng Shan","doi":"10.1177/1748006x241231067","DOIUrl":"https://doi.org/10.1177/1748006x241231067","url":null,"abstract":"The reliability of key components of urban rail transit (URT) plays an important role in the maintenance plans of URT. It is necessary to establish the reliability model of URT trains. In the current research, the reliability model has a limited scope of application and fails to accurately depict the reliability of key components in URT trains. To solve the above problem, a multi-peak type mixture Weibull distribution model is established using several three-parameter Weibull distributions based on fault modes of components sourced from historical lifetime data. Due to the complexity of this model, parameter estimation is challenging. For this purpose, an improved hunter-prey optimization (IHPO) was proposed to improve parameter estimation accuracy. Firstly, an improved Hénon chaos map was introduced to improve the distribution of the initial population. Secondly, the Lévy flight was introduced to increase the probability of the individual spreading to the whole range at the late stage. Lastly, a nonlinear balance factor was proposed to enhance the algorithm’s global search capability. The simulation experiment was carried out with examples of the balanced pressing wheel and the wheelset. The IHPO algorithm-based parameter estimation method shows the highest R-square with values of 0.996 and 0.999, respectively, and the lowest root mean square error with values of 0.019 and 0.008, respectively. The simulation results demonstrate that the stability and optimization of the HPO are improved, and the multi-peak mixture Weibull distribution model based on the IHPO can accurately depict URT trains’ reliability.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"15 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140019981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-27DOI: 10.1177/1748006x241233863
Camila Correa-Jullian, Marilia Ramos, Ali Mosleh, Jiaqi Ma
The safety of Automated Driving Systems (ADS) operating as Mobility as a Service (MaaS) depends on multiple factors in addition to the vehicle’s functionality, reliability, and performance. Currently, no comprehensive approach has been formally developed to identify operational safety hazards and define the operational safety responsibilities of the key agents involved in Level 4 (L4) ADS MaaS operations. This work develops and applies a structured hazard identification methodology for this operation. The methodology leverages and complements the strengths of various hazard identification and modeling methods, including Event Sequence Diagram (ESD), Concurrent Task Analysis (CoTA), System-Theoretic Process Analysis (STPA), and Fault Tree Analysis (FTA). The methodology is applied to analyze the operation of a fleet of L4 ADS vehicle fleets without a safety driver, monitored and supervised by remote operators. The results highlight the fleet operator’s role in ensuring the correct vehicle operation and preventing and mitigating incidents. The analysis demonstrates the developed methodology’s strengths and suitability for operational safety analysis of complex systems’ operations, considering the inherent complexity of the interactions between multiple human and machine agents.
{"title":"Operational safety hazard identification methodology for automated driving systems fleets","authors":"Camila Correa-Jullian, Marilia Ramos, Ali Mosleh, Jiaqi Ma","doi":"10.1177/1748006x241233863","DOIUrl":"https://doi.org/10.1177/1748006x241233863","url":null,"abstract":"The safety of Automated Driving Systems (ADS) operating as Mobility as a Service (MaaS) depends on multiple factors in addition to the vehicle’s functionality, reliability, and performance. Currently, no comprehensive approach has been formally developed to identify operational safety hazards and define the operational safety responsibilities of the key agents involved in Level 4 (L4) ADS MaaS operations. This work develops and applies a structured hazard identification methodology for this operation. The methodology leverages and complements the strengths of various hazard identification and modeling methods, including Event Sequence Diagram (ESD), Concurrent Task Analysis (CoTA), System-Theoretic Process Analysis (STPA), and Fault Tree Analysis (FTA). The methodology is applied to analyze the operation of a fleet of L4 ADS vehicle fleets without a safety driver, monitored and supervised by remote operators. The results highlight the fleet operator’s role in ensuring the correct vehicle operation and preventing and mitigating incidents. The analysis demonstrates the developed methodology’s strengths and suitability for operational safety analysis of complex systems’ operations, considering the inherent complexity of the interactions between multiple human and machine agents.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"2017 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139987680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-27DOI: 10.1177/1748006x241234700
Junting Lin, Qian Li, Yang Wang
In order to achieve the goal of transforming China into a modernized railway powerhouse, a comprehensive evaluation model of intrinsic safety is constructed in this paper by focussing on the intrinsic safety of railway facilities and equipment. Firstly, the index system for evaluating the intrinsic safety of railway facilities and equipment is divided. Secondly, the fuzzy Petri net (FPN) model for intrinsic safety evaluation is constructed according to the fuzzy generative rules, and the similarity calculation method of the cloud model based on shape and distance is applied to derive the initial state value of the FPN model and carry out the calculation of fuzzy reasoning of the intrinsic safety. Finally, the comprehensive evaluation of intrinsic safety is carried out using the example of railroad facilities and equipment at one China Railway Group bureau’s station section. The results indicate that the intrinsic safety level of the station section falls into Class IV intrinsic safety, exhibiting a few vulnerabilities. However, the risk level is low, aligning with the findings of the actual research. Moreover, the evaluation results based on the FPN, the cloud model’s similarity calculation method and the suggested method are compared and analysed with the findings of the actual research. The comparative results demonstrate the accuracy and scientificity of the proposed method, providing a reference for enhancing the intrinsic safety of railway facilities and equipment.
为实现我国向现代化铁路强国转变的目标，本文以铁路设施设备的本质安全为重点，构建了本质安全综合评价模型。首先，划分了铁路设施设备本质安全评价指标体系。其次，根据模糊生成规则构建了本质安全评价的模糊 Petri 网（FPN）模型，并应用基于形状和距离的云模型相似性计算方法得出 FPN 模型的初始状态值，进行本质安全的模糊推理计算。最后，以中铁某局站段铁路设施设备为例，对本质安全进行了综合评价。结果表明，该站段的本质安全等级属于四级本质安全，存在一些薄弱环节。但风险等级较低，与实际研究结果一致。此外，基于 FPN、云模型相似性计算方法和建议方法的评估结果与实际研究结果进行了比较和分析。对比结果证明了建议方法的准确性和科学性，为提高铁路设施设备的本质安全提供了参考。
{"title":"Comprehensive evaluation of intrinsic safety of railway facilities and equipment based on improved cloud model-fuzzy Petri net","authors":"Junting Lin, Qian Li, Yang Wang","doi":"10.1177/1748006x241234700","DOIUrl":"https://doi.org/10.1177/1748006x241234700","url":null,"abstract":"In order to achieve the goal of transforming China into a modernized railway powerhouse, a comprehensive evaluation model of intrinsic safety is constructed in this paper by focussing on the intrinsic safety of railway facilities and equipment. Firstly, the index system for evaluating the intrinsic safety of railway facilities and equipment is divided. Secondly, the fuzzy Petri net (FPN) model for intrinsic safety evaluation is constructed according to the fuzzy generative rules, and the similarity calculation method of the cloud model based on shape and distance is applied to derive the initial state value of the FPN model and carry out the calculation of fuzzy reasoning of the intrinsic safety. Finally, the comprehensive evaluation of intrinsic safety is carried out using the example of railroad facilities and equipment at one China Railway Group bureau’s station section. The results indicate that the intrinsic safety level of the station section falls into Class IV intrinsic safety, exhibiting a few vulnerabilities. However, the risk level is low, aligning with the findings of the actual research. Moreover, the evaluation results based on the FPN, the cloud model’s similarity calculation method and the suggested method are compared and analysed with the findings of the actual research. The comparative results demonstrate the accuracy and scientificity of the proposed method, providing a reference for enhancing the intrinsic safety of railway facilities and equipment.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"32 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139987674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-26DOI: 10.1177/1748006x241233647
Xiaoliang He, Chun Su
Ensuring reliable operation and maximum the output is crucial for energy production systems. Traditional time-based availability (TBA) warranty policies often overlook some factors, such as energy loss and the experience gained during the maintenance activities. In this paper, an innovative warranty policy which focuses on the energy-based availability (EBA) is proposed, where imperfect preventive maintenance (IPM) and minimal repair (MR) are taken into account, and hybrid hazard rate model is adopted to describe the effect of preventive maintenance. In addition, the learning-forgetting effect during the maintenance is considered. On this basis, six types of single-objective and multi-objective models are established, and they are solved by genetic algorithm (GA) and non-dominated sorting genetic algorithm-II (NSGA-II), respectively. To illustrate the effectiveness of the proposed warranty policy, a numerical case of wind turbine gearbox is conducted. The results show that the proposed EBA warranty policy can gain around 0.29% energy more than TBA policy. Compared to single-objective models, multi-objective models can provide more selectable maintenance options. Additionally, sensitivity analysis indicates that by considering the learning-forgetting effect, the gearbox can achieve higher EBA and lower warranty cost.
{"title":"Energy-based availability warranty policy with considering preventive maintenance and learning-forgetting effect","authors":"Xiaoliang He, Chun Su","doi":"10.1177/1748006x241233647","DOIUrl":"https://doi.org/10.1177/1748006x241233647","url":null,"abstract":"Ensuring reliable operation and maximum the output is crucial for energy production systems. Traditional time-based availability (TBA) warranty policies often overlook some factors, such as energy loss and the experience gained during the maintenance activities. In this paper, an innovative warranty policy which focuses on the energy-based availability (EBA) is proposed, where imperfect preventive maintenance (IPM) and minimal repair (MR) are taken into account, and hybrid hazard rate model is adopted to describe the effect of preventive maintenance. In addition, the learning-forgetting effect during the maintenance is considered. On this basis, six types of single-objective and multi-objective models are established, and they are solved by genetic algorithm (GA) and non-dominated sorting genetic algorithm-II (NSGA-II), respectively. To illustrate the effectiveness of the proposed warranty policy, a numerical case of wind turbine gearbox is conducted. The results show that the proposed EBA warranty policy can gain around 0.29% energy more than TBA policy. Compared to single-objective models, multi-objective models can provide more selectable maintenance options. Additionally, sensitivity analysis indicates that by considering the learning-forgetting effect, the gearbox can achieve higher EBA and lower warranty cost.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"627 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139969256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-26DOI: 10.1177/1748006x241232123
Anupam Kumar, Anand Parey, Pavan Kumar Kankar
The vibration signals of a polymer gear are considerably weak and susceptible to ambient noise at the early stage of the fault, which makes the fault difficult to detect. Efficient detection of an early fault in a polymer gear may improve the operation safety of the machinery system that utilizes it for power transmission. This study introduces an innovative approach for the early detection of pitting faults in polymer gears, utilizing condition indicators (CIs) derived from kurtosis-variational mode decomposition (VMD). First, the vibration signal of the polymer gear is decomposed using VMD into several components. Second, the sensitive components are selected to construct a new signal from the first two largest kurtosis values. Third, the CIs are extracted from newly constructed signals, and envelope spectrum analysis is performed. It is observed from the results that the kurtosis-VMD based CIs are effective in the early pitting fault detection of polymer gears. Finally, it is found that the proposed method performs better in all operating conditions considered in the experiment, compared with raw signal and kurtosis-empirical mode decomposition (EMD) based analysis. The proposed method’s response to noise is also explored. Furthermore, the proposed method is compared with the existing time synchronous averaging (TSA), difference, and residual methods.
{"title":"Early pitting fault detection for polymer gears using kurtosis-VMD based condition indicators","authors":"Anupam Kumar, Anand Parey, Pavan Kumar Kankar","doi":"10.1177/1748006x241232123","DOIUrl":"https://doi.org/10.1177/1748006x241232123","url":null,"abstract":"The vibration signals of a polymer gear are considerably weak and susceptible to ambient noise at the early stage of the fault, which makes the fault difficult to detect. Efficient detection of an early fault in a polymer gear may improve the operation safety of the machinery system that utilizes it for power transmission. This study introduces an innovative approach for the early detection of pitting faults in polymer gears, utilizing condition indicators (CIs) derived from kurtosis-variational mode decomposition (VMD). First, the vibration signal of the polymer gear is decomposed using VMD into several components. Second, the sensitive components are selected to construct a new signal from the first two largest kurtosis values. Third, the CIs are extracted from newly constructed signals, and envelope spectrum analysis is performed. It is observed from the results that the kurtosis-VMD based CIs are effective in the early pitting fault detection of polymer gears. Finally, it is found that the proposed method performs better in all operating conditions considered in the experiment, compared with raw signal and kurtosis-empirical mode decomposition (EMD) based analysis. The proposed method’s response to noise is also explored. Furthermore, the proposed method is compared with the existing time synchronous averaging (TSA), difference, and residual methods.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"19 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-19DOI: 10.1177/1748006x241229518
Kamar Diaz, Mohamed Ali Kammoun, Zied Hajej, Naoufal Sefiani, Maria Francesca Milazzo
This paper presents an integrated production, maintenance, and transportation strategy for a multi-site, multi-demand, multi-tank fuel production system. Firstly, each site’s economic fuel production plan is developed under a random demand and service level. Then, a transportation plan is proposed to collaborate between sites in case of unavailability site or unmet needs, minimizing the total cost. According to the correlation between production and maintenance, a periodically preventive maintenance strategy is developed for both refining machines and storage tanks, while minimizing the incurred costs by considering the influence of fuel production rate on their failure rates. Additionally, in this study, experimental tests are performed on an industrial tank, based on the real-life case of fuel companies, to investigate the tanks’ degradation due to corrosion phenomena. The resolution complexity of the analytical model arises from its stochastic nature due to random demands. Hence, a transformation to a deterministic form is performed. Numerical examples and a sensitivity study are presented to illustrate the effectiveness of the proposed methodology and the obtained results.
{"title":"Joint production, transportation, and maintenance in downstream fuel supply chain","authors":"Kamar Diaz, Mohamed Ali Kammoun, Zied Hajej, Naoufal Sefiani, Maria Francesca Milazzo","doi":"10.1177/1748006x241229518","DOIUrl":"https://doi.org/10.1177/1748006x241229518","url":null,"abstract":"This paper presents an integrated production, maintenance, and transportation strategy for a multi-site, multi-demand, multi-tank fuel production system. Firstly, each site’s economic fuel production plan is developed under a random demand and service level. Then, a transportation plan is proposed to collaborate between sites in case of unavailability site or unmet needs, minimizing the total cost. According to the correlation between production and maintenance, a periodically preventive maintenance strategy is developed for both refining machines and storage tanks, while minimizing the incurred costs by considering the influence of fuel production rate on their failure rates. Additionally, in this study, experimental tests are performed on an industrial tank, based on the real-life case of fuel companies, to investigate the tanks’ degradation due to corrosion phenomena. The resolution complexity of the analytical model arises from its stochastic nature due to random demands. Hence, a transformation to a deterministic form is performed. Numerical examples and a sensitivity study are presented to illustrate the effectiveness of the proposed methodology and the obtained results.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"36 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-12DOI: 10.1177/1748006x231209810
Raziye Norouzi Masir, Mohammad Ataei, Farhang Sereshki
The use of resilience during the mining period by guaranteeing the safety and performance of the systems greatly helps the managers and engineers with their decision-making and designing different systems. During the last two decades, various studies have been conducted in this regard. However, the analysis of underground coal mining systems’ resilience has been rarely addressed by these studies. The present study aims to provide a quantitative index for resilience in the environment of underground coal mining operations based on the risk factors. To do so, in a case study of Tabas Mechanized Coal Mine, the Failure of shearer data and the stoppages caused by it (for 2 years and a half, from March 2017 to June 2019) were studied to analyze the system’s resilience. Then, the experts were surveyed. After collecting and categorizing the data, the data analysis calculations were done for indicators of reliability, maintainability, supportability, organizational resilience, PHM system efficiency, and economic resilience. Finally, a new quantitative index named the “Shearer System Resilience Index” was introduced. The results indicated that resilience is reduced over time. They also shows that in order to improve resilience, project managers should pay more attention to these indicators, especially the indicators of maintainability, and organizational resilience. Therefore, regarding the scope of the data investigated in the current study, the use of Failure of Shearer data-based risk factors and experts’ opinions for the analysis of resilience in the case study is strongly recommended.
{"title":"A novel index for shearer system resilience in underground coal mines based on the operational environment","authors":"Raziye Norouzi Masir, Mohammad Ataei, Farhang Sereshki","doi":"10.1177/1748006x231209810","DOIUrl":"https://doi.org/10.1177/1748006x231209810","url":null,"abstract":"The use of resilience during the mining period by guaranteeing the safety and performance of the systems greatly helps the managers and engineers with their decision-making and designing different systems. During the last two decades, various studies have been conducted in this regard. However, the analysis of underground coal mining systems’ resilience has been rarely addressed by these studies. The present study aims to provide a quantitative index for resilience in the environment of underground coal mining operations based on the risk factors. To do so, in a case study of Tabas Mechanized Coal Mine, the Failure of shearer data and the stoppages caused by it (for 2 years and a half, from March 2017 to June 2019) were studied to analyze the system’s resilience. Then, the experts were surveyed. After collecting and categorizing the data, the data analysis calculations were done for indicators of reliability, maintainability, supportability, organizational resilience, PHM system efficiency, and economic resilience. Finally, a new quantitative index named the “Shearer System Resilience Index” was introduced. The results indicated that resilience is reduced over time. They also shows that in order to improve resilience, project managers should pay more attention to these indicators, especially the indicators of maintainability, and organizational resilience. Therefore, regarding the scope of the data investigated in the current study, the use of Failure of Shearer data-based risk factors and experts’ opinions for the analysis of resilience in the case study is strongly recommended.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"92 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The reliability of cyber-physical microgrids (MGs) is crucial in the development of smart grids. The reliability of MGs can be affected by cyber network failures, which have a significant impact on the physical components. Since MGs have interdependent cyber and physical elements, a smart MG can be viewed as a system of n dependent two-mode components. This paper proposes an approach to finding the k most likely configurations of the system. The method involves three phases. Firstly, the multi-mode model is obtained for physical components, considering the operation and topology of the cyber network. Then, the problem is transformed to finding the k most likely state of a system consisting of n independent multi-mode components. In the second phase, a transformation using new transformed metrics is applied. This results in the problem being converted to finding the k shortest path, which can be solved using efficient algorithms. Finally, the states are evaluated using a DC load flow, and reliability indices such as loss of load probability (LOLP) and expected energy not supplied (EENS) are calculated. Moreover, we have incorporated the dynamic thermal rating (DTR) system into our proposed model, addressing the safe enhancement of system component ratings. The results indicate that the most probable states of the system are related to the failure of distribution generators. The most severe events occur due to failure in the cyber network, and cyber network malfunction has a higher effect on EENS compared to LOLP. Additionally, we observe a significant enhancement in reliability indices when considering the DTR system over the static thermal rating (STR) system.This approach is efficient in reliability calculation using fewer system states.
网络物理微电网（MGs）的可靠性对智能电网的发展至关重要。微电网的可靠性会受到网络故障的影响，而网络故障会对物理元件产生重大影响。由于 MG 具有相互依赖的网络和物理元件，因此可以将智能 MG 视为由 n 个相互依赖的双模元件组成的系统。本文提出了一种寻找系统 k 种最可能配置的方法。该方法包括三个阶段。首先，考虑到网络的运行和拓扑结构，获得物理元件的多模式模型。然后，将问题转换为寻找由 n 个独立多模式组件组成的系统的 k 个最可能状态。在第二阶段，使用新的转换指标进行转换。其结果是将问题转换为寻找 k 条最短路径，这可以通过高效算法来解决。最后，使用直流负载流对状态进行评估，并计算出可靠性指数，如负载损失概率 (LOLP) 和预期未供应能量 (EENS)。此外，我们还将动态热额定值（DTR）系统纳入了我们提出的模型，以解决系统组件额定值的安全提升问题。结果表明，系统最可能出现的状态与配电发电机故障有关。最严重的事件发生在网络故障上，与 LOLP 相比，网络故障对 EENS 的影响更大。此外，与静态热额定值（STR）系统相比，我们观察到 DTR 系统的可靠性指数显著提高。
{"title":"A new approach for reliability assessment of the smart microgrids using k-shortest path algorithms","authors":"Mohammadreza Gholami, Meysam Mohammadtaheri, Alireza Gholami","doi":"10.1177/1748006x231214337","DOIUrl":"https://doi.org/10.1177/1748006x231214337","url":null,"abstract":"The reliability of cyber-physical microgrids (MGs) is crucial in the development of smart grids. The reliability of MGs can be affected by cyber network failures, which have a significant impact on the physical components. Since MGs have interdependent cyber and physical elements, a smart MG can be viewed as a system of n dependent two-mode components. This paper proposes an approach to finding the k most likely configurations of the system. The method involves three phases. Firstly, the multi-mode model is obtained for physical components, considering the operation and topology of the cyber network. Then, the problem is transformed to finding the k most likely state of a system consisting of n independent multi-mode components. In the second phase, a transformation using new transformed metrics is applied. This results in the problem being converted to finding the k shortest path, which can be solved using efficient algorithms. Finally, the states are evaluated using a DC load flow, and reliability indices such as loss of load probability (LOLP) and expected energy not supplied (EENS) are calculated. Moreover, we have incorporated the dynamic thermal rating (DTR) system into our proposed model, addressing the safe enhancement of system component ratings. The results indicate that the most probable states of the system are related to the failure of distribution generators. The most severe events occur due to failure in the cyber network, and cyber network malfunction has a higher effect on EENS compared to LOLP. Additionally, we observe a significant enhancement in reliability indices when considering the DTR system over the static thermal rating (STR) system.This approach is efficient in reliability calculation using fewer system states.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"2 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-08DOI: 10.1177/1748006x231205382
Yiming Ma, Mingguang Zhang, Mingliang Wang
The chemical industry involves the production, storage, and use of many flammable, explosive, toxic, and other hazardous chemicals. Once an accident occurs, it will cause serious harm to human and economic activities. In order to prevent chemical accidents, this paper combines Interpretive Structural Modeling (ISM) and Bayesian network (BN) to quantitatively study the relationship and interaction strength among accident risk factors in chemical industry. Through the analysis of accident cases and questionnaire survey, 21 accident risk factors in chemical industry are selected. According to the decision of experts, the influence relationship between risk factors is determined, and a multi-level directed graph of ISM is obtained. And the ISM model is transformed into a quantitative BN model. The BN model is applied to forward reasoning, sensitivity analysis, and reverse reasoning. The results indicate that there is a positive correlation between various risk factors and chemical accidents, and the supervision mechanism has the highest probability of occurrence in production activities. Illegal operation has the highest sensitivity and the greatest impact on chemical accidents. Inherent hazards of materials and products is the most likely cause of accidents. Based on the research results, feasible measures have been proposed to improve safety management in the chemical industry.
{"title":"Analysis of accident risk factors in chemical industry based on ISM-BN","authors":"Yiming Ma, Mingguang Zhang, Mingliang Wang","doi":"10.1177/1748006x231205382","DOIUrl":"https://doi.org/10.1177/1748006x231205382","url":null,"abstract":"The chemical industry involves the production, storage, and use of many flammable, explosive, toxic, and other hazardous chemicals. Once an accident occurs, it will cause serious harm to human and economic activities. In order to prevent chemical accidents, this paper combines Interpretive Structural Modeling (ISM) and Bayesian network (BN) to quantitatively study the relationship and interaction strength among accident risk factors in chemical industry. Through the analysis of accident cases and questionnaire survey, 21 accident risk factors in chemical industry are selected. According to the decision of experts, the influence relationship between risk factors is determined, and a multi-level directed graph of ISM is obtained. And the ISM model is transformed into a quantitative BN model. The BN model is applied to forward reasoning, sensitivity analysis, and reverse reasoning. The results indicate that there is a positive correlation between various risk factors and chemical accidents, and the supervision mechanism has the highest probability of occurrence in production activities. Illegal operation has the highest sensitivity and the greatest impact on chemical accidents. Inherent hazards of materials and products is the most likely cause of accidents. Based on the research results, feasible measures have been proposed to improve safety management in the chemical industry.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135390583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-07DOI: 10.1177/1748006x231199790
Jaber Kazempoor, Arezou Habibirad
In this paper, we consider the preventive perfect replacement and replacement by a new one policies for some arbitrary selected components in the repairable series and parallel systems with dependent components. These policies are also extended to other systems. In fact, regardless of the kind of system, the policies are applied to any system with a survival function that can be calculated as a known function of their component’s survival functions. The dependent structure of these components is formulated regarding copula frameworks. In addition, two optimal maintenance policies in accordance with the maximum expected life for a series and parallel system and minimum/maximum relative risk of a component for a series/parallel system have been provided. The problem issue of finding the optimal relative risk of a component is new and has not been proposed up to now. Although the optimal life extension of a system has been investigated previously, through a replacement policy of the whole system, in this study, the life of a series or parallel system is optimally extended through a replacement policy of some of its dependent components. The existence of the optimal solution has been shown for all copula functions and furthermore, some numerical results are detailed regarding the Gumbel, Frank, Joe, Clayton, FGM, Normal, and AMH copulas.
{"title":"Component-based perfect replacement optimizations for series and parallel systems consisting of repairable dependent components","authors":"Jaber Kazempoor, Arezou Habibirad","doi":"10.1177/1748006x231199790","DOIUrl":"https://doi.org/10.1177/1748006x231199790","url":null,"abstract":"In this paper, we consider the preventive perfect replacement and replacement by a new one policies for some arbitrary selected components in the repairable series and parallel systems with dependent components. These policies are also extended to other systems. In fact, regardless of the kind of system, the policies are applied to any system with a survival function that can be calculated as a known function of their component’s survival functions. The dependent structure of these components is formulated regarding copula frameworks. In addition, two optimal maintenance policies in accordance with the maximum expected life for a series and parallel system and minimum/maximum relative risk of a component for a series/parallel system have been provided. The problem issue of finding the optimal relative risk of a component is new and has not been proposed up to now. Although the optimal life extension of a system has been investigated previously, through a replacement policy of the whole system, in this study, the life of a series or parallel system is optimally extended through a replacement policy of some of its dependent components. The existence of the optimal solution has been shown for all copula functions and furthermore, some numerical results are detailed regarding the Gumbel, Frank, Joe, Clayton, FGM, Normal, and AMH copulas.","PeriodicalId":51266,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part O-Journal of Risk and Reliability","volume":"302 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135475325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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