To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(...To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(CR) as benefit, and the maximum modification compared to the original pairwise comparison matrix(PCM) as cost, then the improvement of consistency is transformed to a benefit/cost analysis problem. According to the maximal marginal effect principle, the elements of PCM are modified by a fixed increment(or decrement) step by step till the consistency ratio becomes acceptable, which can ensure minimum adjustment to the original PCM so that the decision makers’ judgment is preserved as much as possible. The correctness of the proposed method is proved mathematically by theorem. Firstly, the marginal benefit/cost ratio is calculated for each single element of the PCM when it has been modified by a fixed increment(or decrement).Then, modification to the element with the maximum marginal benefit/cost ratio is accepted. Next, the marginal benefit/cost ratio is calculated again upon the revised matrix, and followed by choosing the modification to the element with the maximum marginal benefit/cost ratio. The process of calculating marginal effect and choosing the best modified element is repeated for each revised matrix till acceptable consistency is reached, i.e., CR<0.1. Finally,illustrative examples show the proposed method is more effective and better in preserving the original comparison information than existing methods.展开更多
Selection of materials,as an area of design research,has been under considerable interest over the years.Materials selection is one of the most important activities in the product development process.Inappropriate dec...Selection of materials,as an area of design research,has been under considerable interest over the years.Materials selection is one of the most important activities in the product development process.Inappropriate decision of materials can cause the product to be reproduced or remanufactured.To avoid this circumstance,one of the useful tools that can be employed in determining the most appropriate material is analytical hierarchy process(AHP).To illustrate the application of AHP,six different types of composite materials were considered.The most appropriate one for suitability of use in manufacturing automotive bumper beam was determined by considering eight main selection factors and 12 sub-factors.The AHP analysis reveals that the glass fibre epoxy is the most appropriate material because it has the highest value(25.7%,mass fraction) compared with other materials.The final material is obtained by performing six different scenarios of the sensitivity analysis.It is proved that glass fibre epoxy is the most optimum decision.展开更多
Test of consistency is critical for the analytic hierarchy process(AHP) methodology. When a pairwise comparison matrix(PCM) fails the consistency test, the decision maker(DM) needs to make revisions. The state of the ...Test of consistency is critical for the analytic hierarchy process(AHP) methodology. When a pairwise comparison matrix(PCM) fails the consistency test, the decision maker(DM) needs to make revisions. The state of the art focuses on changing a single entry or creating a new matrix based on the original inconsistent matrix so that the modified matrix can satisfy the consistency requirement. However, we have noticed that the reason that causes inconsistency is not only numerical inconsistency, but also logical inconsistency, which may play a more important role in the whole inconsistency. Therefore, to realize satisfactory consistency, first of all, we should change some entries that form a directed circuit to make the matrix logically consistent, and then adjust other entries within acceptable deviations to make the matrix numerically consistent while preserving most of the original comparison information. In this paper, we firstly present some definitions and theories, based on which two effective methods are provided to identify directed circuits. Four optimization models are proposed to adjust the original inconsistent matrix. Finally, illustrative examples and comparison studies show the effectiveness and feasibility of our method.展开更多
Structuring the hierarchy of a system is an important link of solving problems with the analytic hierarchy process. This paper gives and proves the two theorems about the relationship between the hierarchy and the rea...Structuring the hierarchy of a system is an important link of solving problems with the analytic hierarchy process. This paper gives and proves the two theorems about the relationship between the hierarchy and the reachability matrix of the system. On the basis of it, we propose a method of structuring hierarchy by directly using the reachability matrix of the system. This method is simpler and clearer than that of interpretive structural modeling and is suitable for both manual calculating and computer proceeding. It fully shows the simplicity of the AHP.展开更多
In operation,risk arising from power transformer faults is of much uncertainty and complicacy.To timely and objectively control the risks,a transformer risk assessment method based on fuzzy analytic hierarchy process(...In operation,risk arising from power transformer faults is of much uncertainty and complicacy.To timely and objectively control the risks,a transformer risk assessment method based on fuzzy analytic hierarchy process(FAHP) and artificial neural network(ANN) from the perspective of accuracy and quickness is proposed.An analytic hierarchy process model for the transformer risk assessment is built by analysis of the risk factors affecting the transformer risk level and the weight relation of each risk factor in transformer risk calculation is analyzed by application of fuzzy consistency judgment matrix;with utilization of adaptive ability and nonlinear mapping ability of the ANN,the risk factors with large weights are used as input of neutral network,and thus intelligent quantitative assessment of transformer risk is realized.The simulation result shows that the proposed method increases the speed and accuracy of the risk assessment and can provide feasible decision basis for the transformer risk management and maintenance decisions.展开更多
The weighted arithmetical mean complex judgement matrix （WAMCJM） is the most common method for aggregating group opinions, but it has a shortcoming, namely the WAMCJM of the perfectly consistent judgement matrices g...The weighted arithmetical mean complex judgement matrix （WAMCJM） is the most common method for aggregating group opinions, but it has a shortcoming, namely the WAMCJM of the perfectly consistent judgement matrices given by experts canot guarantee its perfect consistency. An upper bound of the WAMCJM＇s consistency is presented. Simultaneously, a compatibility index of judging the aggregating extent of group opinions is also introduced. The WAMCJM is of acceptable consistency and is proved provided the compatibilities of all judgement matrices given by experts are smaller than the threshold value of acceptable consistency. These conclusions are important to group decision making.展开更多
Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phospho...Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phosphorus mines encounters great challenges. For this purpose, a man-machine-environment system composed of evaluation indexes was established, and the grading standards of indexes were defined. Firstly, the measurements of 39 qualitative indexes were obtained through the survey data. According to the measured values of 31 quantitative indexes, the measurements of quantitative indexes were calculated by linear measurement function(LM) and other three functions. Then the singleindex measurement evaluation matrixes were established. Secondly, the entropy weight method was used to determine the weights of each index directly. The analytic hierarchy process(AHP) was also applied to calculate the weights of index and index factor hierarchies after the established hierarchical model. The weights of system hierarchies were given by the grid-based fuzzy Borda method(GFB). The comprehensive weights were determined by the combination method of AHP and GFB(CAG). Furthermore, the multi-index comprehensive measurement evaluation vectors were obtained.Thirdly, the vectors were evaluated by the credible degree recognition(CDR) and the maximum membership(TMM)criteria. Based on the above functions, methods, and criteria, 16 combination evaluation methods were recommended.Finally, the clean and safe production grade of Kaiyang phosphate mine in China was evaluated. The results show that the LM-CAG-CDR is the most reasonable method, which can not only determine the clean and safe production grade of phosphorus mines, but also improve the development level of clean and safe mining of phosphorus mines for guidance.In addition, some beneficial suggestions and measures were also proposed to advance the clean and safe production grade of Kaiyang phosphorus mine.展开更多
Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process （AHP） accumulation factor, namely Solving Weight by AHP＇s Accumulati...Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process （AHP） accumulation factor, namely Solving Weight by AHP＇s Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable展开更多
In the conceptual design stage of complex products, CBR（Case-Based Reasoning） tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and e...In the conceptual design stage of complex products, CBR（Case-Based Reasoning） tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and evaluation. The procedure is essentially a multiple criteria decision-making problem. The traditional multiple criteria programming is not flexible enough in executing the system evaluation algorithm due to both the limited experimental data and the lack of human experiences. To make the CBR tool to be more efficient, a new method for the best choice among the feasible schemes based on the Fuzzy AHP using Fuzzy numbers （FFAHP） is proposed. Since the final results become a problem of ranking the mean of fuzzy numbers by the optimism of decision-maker using the FFAHP, its execution is much more intuitive and effective than with the traditional method.展开更多
Failure mechanisms of power transformers are complex and uncertain; it is difficult to determine index weights of insulation state. Therefore, it is a challenge to acquire an accurate assessment of insulation state of...Failure mechanisms of power transformers are complex and uncertain; it is difficult to determine index weights of insulation state. Therefore, it is a challenge to acquire an accurate assessment of insulation state of power transformers. In this paper, an assessing strategy for transformer insulation is proposed base on part-division of transformer and a comprehensive weight determination method. An index system of transformer is established on the basis of part-division of transformer. Each index’s weight is consisted of two parts, the constant weight and the variable weight, which are determined by improved analytic hierarchy process (AHP) and entropy method respectively. Af- ter categorizing insulation state into four levels and standardizing assessing indexes, a Cauchy membership function is forged, and a fuzzy algorithm is employed to simulate the uncertainty of the insulation state. Finally, a confidence criterion is employed to perform part-division based condition assessment of transformer. Case studies reveal that the proposed assessing strategy method is effective, convenient, and practical; with the new strategy, potential failures of transformers can be forecasted and insulation state of transformer parts can also be as- sessed. Furthermore, the assessing results can be used to guide condition-based maintenance.展开更多
A comprehensive assessment index system was established. The mechanical recycling process of printed circuit board was evaluated according to the comprehensive evaluation index system using the fuzzy analytic hierarch...A comprehensive assessment index system was established. The mechanical recycling process of printed circuit board was evaluated according to the comprehensive evaluation index system using the fuzzy analytic hierarchy process. A process assessment software system of mechanical recycling was established to evaluate different recycling technologies. And the software system was developed in the environment of VB6.0 and Access2000.展开更多
Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily dam...Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily damaged.Once the structure of high-pile wharf destroyed,it is bound to be a great threat to the safety of various facilities and personnel in the port.Given all of that,the multi-level comprehensive evaluation method based on the extension theory is proposed in this paper.Using this method to assess the safety of high-pile wharf structure,the reasonable advice on its maintenance and reinforcement can be given in time.What’s more,the method is simple and can give more objective result of the evaluation.展开更多
To overcome the limitations of the traditional surrogate worth trade-off （SWT） method and solve the multiple criteria decision making problem more efficiently and interactively, a new method labeled dual worth trade...To overcome the limitations of the traditional surrogate worth trade-off （SWT） method and solve the multiple criteria decision making problem more efficiently and interactively, a new method labeled dual worth tradeoff （DWT） method is proposed. The DWT method dynamically uses the duality theory related to the multiple criteria decision making problem and analytic hierarchy process technique to obtain the decision maker＇s solution preference information and finally find the satisfactory compromise solution of the decision maker. Through the interactive process between the analyst and the decision maker, trade-off information is solicited and treated properly, the representative subset of efficient solutions and the satisfactory solution to the problem are found. The implementation procedure for the DWT method is presented. The effectiveness and applicability of the DWT method are shown by a practical case study in the field of production scheduling.展开更多
The power transformer is the key equipment of transforming voltage and exchanging power in the power system.It's safe and reliable operation directly influences the safe level of the power system.To study the risk...The power transformer is the key equipment of transforming voltage and exchanging power in the power system.It's safe and reliable operation directly influences the safe level of the power system.To study the risk assessment of power transformer which is very significant to improve the reliability of the power system,a fuzzy comprehensive risk assessment model of power transformer based on Borda number theory is proposed in this paper.At first,the fault types and risk factors of the power transformer are analyzed.Secondly,the basic framework of the fuzzy comprehensive evaluation is applied to quantify the risk factors.And then,Borda number theory is employed to analyze influence degree and occurrence probability of power transformer.At last,the various risk factors impact index and fuzzy comprehensive evaluation index of power transformer can be easily obtained.Applying this model,the relative importance degree of the risk factors can be horizontally compared according to the numerical index,the engineering staff can directly get the parameters of the transformer risk level and get a good description of the visual expression through using 5 score and similar visual language.展开更多
氢电混动汽车(fuel-cell hybrid electric vehicles,FCHEV)的出现有效促进了能源-交通系统的绿色低碳转型。现阶段关于FCHEV的研究主要集中在能量管理和控制策略上,较少关注灵活性潜力评估方面,为此,提出了一种计及车主充能意愿差异性的...氢电混动汽车(fuel-cell hybrid electric vehicles,FCHEV)的出现有效促进了能源-交通系统的绿色低碳转型。现阶段关于FCHEV的研究主要集中在能量管理和控制策略上,较少关注灵活性潜力评估方面,为此,提出了一种计及车主充能意愿差异性的FCHEV集群灵活性潜力评估方法。首先,建立城市交通路网模型模拟FCHEV的出行特征,进而建立单体FCHEV充能模型;其次,利用改进层次分析法并结合熵权法建立车主充能意愿综合评价体系,并综合考虑禀赋效应和环保意识对车主响应意愿度的影响;最后,建立FCHEV集群灵活性潜力评估模型,求解得出潜力评估结果。仿真结果表明,所提方法在评估过程中能够合理刻画车主充能意愿的差异性,并有效提高集群参与优化调度时系统的灵活性。展开更多
基金supported by the National Natural Science Foundation of China(6160150161502521)
文摘To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(CR) as benefit, and the maximum modification compared to the original pairwise comparison matrix(PCM) as cost, then the improvement of consistency is transformed to a benefit/cost analysis problem. According to the maximal marginal effect principle, the elements of PCM are modified by a fixed increment(or decrement) step by step till the consistency ratio becomes acceptable, which can ensure minimum adjustment to the original PCM so that the decision makers’ judgment is preserved as much as possible. The correctness of the proposed method is proved mathematically by theorem. Firstly, the marginal benefit/cost ratio is calculated for each single element of the PCM when it has been modified by a fixed increment(or decrement).Then, modification to the element with the maximum marginal benefit/cost ratio is accepted. Next, the marginal benefit/cost ratio is calculated again upon the revised matrix, and followed by choosing the modification to the element with the maximum marginal benefit/cost ratio. The process of calculating marginal effect and choosing the best modified element is repeated for each revised matrix till acceptable consistency is reached, i.e., CR<0.1. Finally,illustrative examples show the proposed method is more effective and better in preserving the original comparison information than existing methods.
基金the financial support through Research University Grant Scheme 2007 (RUG 2007) with vote number 91045
文摘Selection of materials,as an area of design research,has been under considerable interest over the years.Materials selection is one of the most important activities in the product development process.Inappropriate decision of materials can cause the product to be reproduced or remanufactured.To avoid this circumstance,one of the useful tools that can be employed in determining the most appropriate material is analytical hierarchy process(AHP).To illustrate the application of AHP,six different types of composite materials were considered.The most appropriate one for suitability of use in manufacturing automotive bumper beam was determined by considering eight main selection factors and 12 sub-factors.The AHP analysis reveals that the glass fibre epoxy is the most appropriate material because it has the highest value(25.7%,mass fraction) compared with other materials.The final material is obtained by performing six different scenarios of the sensitivity analysis.It is proved that glass fibre epoxy is the most optimum decision.
基金supported by the National Natural Science Foundation of China(61601501 61502521)
文摘Test of consistency is critical for the analytic hierarchy process(AHP) methodology. When a pairwise comparison matrix(PCM) fails the consistency test, the decision maker(DM) needs to make revisions. The state of the art focuses on changing a single entry or creating a new matrix based on the original inconsistent matrix so that the modified matrix can satisfy the consistency requirement. However, we have noticed that the reason that causes inconsistency is not only numerical inconsistency, but also logical inconsistency, which may play a more important role in the whole inconsistency. Therefore, to realize satisfactory consistency, first of all, we should change some entries that form a directed circuit to make the matrix logically consistent, and then adjust other entries within acceptable deviations to make the matrix numerically consistent while preserving most of the original comparison information. In this paper, we firstly present some definitions and theories, based on which two effective methods are provided to identify directed circuits. Four optimization models are proposed to adjust the original inconsistent matrix. Finally, illustrative examples and comparison studies show the effectiveness and feasibility of our method.
文摘Structuring the hierarchy of a system is an important link of solving problems with the analytic hierarchy process. This paper gives and proves the two theorems about the relationship between the hierarchy and the reachability matrix of the system. On the basis of it, we propose a method of structuring hierarchy by directly using the reachability matrix of the system. This method is simpler and clearer than that of interpretive structural modeling and is suitable for both manual calculating and computer proceeding. It fully shows the simplicity of the AHP.
基金Project(50977003) supported by the National Natural Science Foundation of China
文摘In operation,risk arising from power transformer faults is of much uncertainty and complicacy.To timely and objectively control the risks,a transformer risk assessment method based on fuzzy analytic hierarchy process(FAHP) and artificial neural network(ANN) from the perspective of accuracy and quickness is proposed.An analytic hierarchy process model for the transformer risk assessment is built by analysis of the risk factors affecting the transformer risk level and the weight relation of each risk factor in transformer risk calculation is analyzed by application of fuzzy consistency judgment matrix;with utilization of adaptive ability and nonlinear mapping ability of the ANN,the risk factors with large weights are used as input of neutral network,and thus intelligent quantitative assessment of transformer risk is realized.The simulation result shows that the proposed method increases the speed and accuracy of the risk assessment and can provide feasible decision basis for the transformer risk management and maintenance decisions.
基金the National Natural Science Foundation of China (705250047047103570121001).
文摘The weighted arithmetical mean complex judgement matrix （WAMCJM） is the most common method for aggregating group opinions, but it has a shortcoming, namely the WAMCJM of the perfectly consistent judgement matrices given by experts canot guarantee its perfect consistency. An upper bound of the WAMCJM＇s consistency is presented. Simultaneously, a compatibility index of judging the aggregating extent of group opinions is also introduced. The WAMCJM is of acceptable consistency and is proved provided the compatibilities of all judgement matrices given by experts are smaller than the threshold value of acceptable consistency. These conclusions are important to group decision making.
基金Project(51974362) supported by the National Natural Science Foundation of ChinaProject(2282020cxqd055) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2021-QYC-10050-25631) supported by the Department of Emergency Management of Hunan Province,China。
文摘Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phosphorus mines encounters great challenges. For this purpose, a man-machine-environment system composed of evaluation indexes was established, and the grading standards of indexes were defined. Firstly, the measurements of 39 qualitative indexes were obtained through the survey data. According to the measured values of 31 quantitative indexes, the measurements of quantitative indexes were calculated by linear measurement function(LM) and other three functions. Then the singleindex measurement evaluation matrixes were established. Secondly, the entropy weight method was used to determine the weights of each index directly. The analytic hierarchy process(AHP) was also applied to calculate the weights of index and index factor hierarchies after the established hierarchical model. The weights of system hierarchies were given by the grid-based fuzzy Borda method(GFB). The comprehensive weights were determined by the combination method of AHP and GFB(CAG). Furthermore, the multi-index comprehensive measurement evaluation vectors were obtained.Thirdly, the vectors were evaluated by the credible degree recognition(CDR) and the maximum membership(TMM)criteria. Based on the above functions, methods, and criteria, 16 combination evaluation methods were recommended.Finally, the clean and safe production grade of Kaiyang phosphate mine in China was evaluated. The results show that the LM-CAG-CDR is the most reasonable method, which can not only determine the clean and safe production grade of phosphorus mines, but also improve the development level of clean and safe mining of phosphorus mines for guidance.In addition, some beneficial suggestions and measures were also proposed to advance the clean and safe production grade of Kaiyang phosphorus mine.
文摘Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process （AHP） accumulation factor, namely Solving Weight by AHP＇s Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable
基金This project was partly supported bythe Key Programof the National Natural Science Foundation of China (79990580) .
文摘In the conceptual design stage of complex products, CBR（Case-Based Reasoning） tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and evaluation. The procedure is essentially a multiple criteria decision-making problem. The traditional multiple criteria programming is not flexible enough in executing the system evaluation algorithm due to both the limited experimental data and the lack of human experiences. To make the CBR tool to be more efficient, a new method for the best choice among the feasible schemes based on the Fuzzy AHP using Fuzzy numbers （FFAHP） is proposed. Since the final results become a problem of ranking the mean of fuzzy numbers by the optimism of decision-maker using the FFAHP, its execution is much more intuitive and effective than with the traditional method.
基金Project supported by Fund for Innovative Research Groups of China (51021005)Fundamental Research Fund for the Central Universities of China(CDJRC10150004)
文摘Failure mechanisms of power transformers are complex and uncertain; it is difficult to determine index weights of insulation state. Therefore, it is a challenge to acquire an accurate assessment of insulation state of power transformers. In this paper, an assessing strategy for transformer insulation is proposed base on part-division of transformer and a comprehensive weight determination method. An index system of transformer is established on the basis of part-division of transformer. Each index’s weight is consisted of two parts, the constant weight and the variable weight, which are determined by improved analytic hierarchy process (AHP) and entropy method respectively. Af- ter categorizing insulation state into four levels and standardizing assessing indexes, a Cauchy membership function is forged, and a fuzzy algorithm is employed to simulate the uncertainty of the insulation state. Finally, a confidence criterion is employed to perform part-division based condition assessment of transformer. Case studies reveal that the proposed assessing strategy method is effective, convenient, and practical; with the new strategy, potential failures of transformers can be forecasted and insulation state of transformer parts can also be as- sessed. Furthermore, the assessing results can be used to guide condition-based maintenance.
文摘A comprehensive assessment index system was established. The mechanical recycling process of printed circuit board was evaluated according to the comprehensive evaluation index system using the fuzzy analytic hierarchy process. A process assessment software system of mechanical recycling was established to evaluate different recycling technologies. And the software system was developed in the environment of VB6.0 and Access2000.
文摘Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily damaged.Once the structure of high-pile wharf destroyed,it is bound to be a great threat to the safety of various facilities and personnel in the port.Given all of that,the multi-level comprehensive evaluation method based on the extension theory is proposed in this paper.Using this method to assess the safety of high-pile wharf structure,the reasonable advice on its maintenance and reinforcement can be given in time.What’s more,the method is simple and can give more objective result of the evaluation.
基金This project was supported by the National Natural Science Foundation of China(79870030)
文摘To overcome the limitations of the traditional surrogate worth trade-off （SWT） method and solve the multiple criteria decision making problem more efficiently and interactively, a new method labeled dual worth tradeoff （DWT） method is proposed. The DWT method dynamically uses the duality theory related to the multiple criteria decision making problem and analytic hierarchy process technique to obtain the decision maker＇s solution preference information and finally find the satisfactory compromise solution of the decision maker. Through the interactive process between the analyst and the decision maker, trade-off information is solicited and treated properly, the representative subset of efficient solutions and the satisfactory solution to the problem are found. The implementation procedure for the DWT method is presented. The effectiveness and applicability of the DWT method are shown by a practical case study in the field of production scheduling.
基金Project Supported by National Natural Science Foundation of China （50425722）, Natural Science Foundation of CQ CSTC （Chongqing Science and Technology Commission） （2008BA3026）.
文摘The power transformer is the key equipment of transforming voltage and exchanging power in the power system.It's safe and reliable operation directly influences the safe level of the power system.To study the risk assessment of power transformer which is very significant to improve the reliability of the power system,a fuzzy comprehensive risk assessment model of power transformer based on Borda number theory is proposed in this paper.At first,the fault types and risk factors of the power transformer are analyzed.Secondly,the basic framework of the fuzzy comprehensive evaluation is applied to quantify the risk factors.And then,Borda number theory is employed to analyze influence degree and occurrence probability of power transformer.At last,the various risk factors impact index and fuzzy comprehensive evaluation index of power transformer can be easily obtained.Applying this model,the relative importance degree of the risk factors can be horizontally compared according to the numerical index,the engineering staff can directly get the parameters of the transformer risk level and get a good description of the visual expression through using 5 score and similar visual language.
文摘氢电混动汽车(fuel-cell hybrid electric vehicles,FCHEV)的出现有效促进了能源-交通系统的绿色低碳转型。现阶段关于FCHEV的研究主要集中在能量管理和控制策略上,较少关注灵活性潜力评估方面,为此,提出了一种计及车主充能意愿差异性的FCHEV集群灵活性潜力评估方法。首先,建立城市交通路网模型模拟FCHEV的出行特征,进而建立单体FCHEV充能模型;其次,利用改进层次分析法并结合熵权法建立车主充能意愿综合评价体系,并综合考虑禀赋效应和环保意识对车主响应意愿度的影响;最后,建立FCHEV集群灵活性潜力评估模型,求解得出潜力评估结果。仿真结果表明,所提方法在评估过程中能够合理刻画车主充能意愿的差异性,并有效提高集群参与优化调度时系统的灵活性。
