Power Transformers Health Index Calculation Method Based on Cloud Model and Fuzzy Evidential Reasoning

2014 ◽  
Vol 1070-1072 ◽  
pp. 1021-1028
Author(s):  
De Hua Cai ◽  
Xi Yang ◽  
Rui Chuang Wang ◽  
Cheng Zhi Ma ◽  
Jin Cheng ◽  
...  

Transformers health index calculation method based on cloud model and fuzzy evidential reasoning is proposed. According to the multi-level and multifactor of evaluation index information of power transformers, a layered evaluation index model is established. In order to deal with the ambiguity and uncertainty information of evaluation index, a normal cloud model is introduced, inferred the fuzzy degree of belief in the health state of evaluation index. Then use the fuzzy evidential reasoning method merge information of evaluation Index, inferred the degree of belief in the health state-level of transformer, calculated the health index of transformer. The results of an example analysis test its rationality and effectiveness.

2019 ◽  
Vol 9 (22) ◽  
pp. 4877 ◽  
Author(s):  
Patryk Bohatyrewicz ◽  
Janusz Płowucha ◽  
Jan Subocz

In electric power systems, health index algorithms are mostly used for evaluation of the transformer population. In this method, some assessment criteria are insensitive when it comes to judging the technical state of the edges of the age spectrum. This paper presents a new health index calculation method that aims to improve the overall effectiveness of the assessment. The proposed algorithm is based on regularly conducted oil diagnostics and easily available maintenance data to enable estimation and updating of the device’s health status in short intervals from an operational point of view. This method is compared to another health index algorithm built from the same parameters, but with different weights and an alternative result assessment philosophy. The two health index calculation methods are tested on a population of 96 power transformers and then compared to results obtained with an expert system, which is based on much more advanced diagnostic tests to determine the technical condition of the unit. The results of the experiment show that proper selection of weighting factors of the transformer’s technical condition parameters during health index calculation may help in simplifying its assessment while maintaining satisfactory accuracy in comparison to a highly advanced expert method.


Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 266
Author(s):  
Wenzhi Cao ◽  
Jilin Deng ◽  
Yi Yang ◽  
Yangyan Zeng ◽  
Limei Liu

The scientific and reasonable evaluation of the carrying capacity of water resources is of guiding significance for solving the issues of water resource shortages and pollution control. It is also an important method for realizing the sustainable development of water resources. Aiming at an evaluation of the carrying capacity of water resources, an evaluation model based on the cloud model theory and evidential reasoning approach is studied. First, based on the existing indicators, a water resources evaluation index system based on the pressure-state-response (PSR) model is constructed, and a classification method of carrying capacity grade is designed. The cloud model theory is used to realize the transformation between the measured value of indicators and the degree of correlation. Second, to obtain the weight of the evaluation index, the weight method of the index weights model based on the entropy weight method and evidential reasoning approach is proposed. Then, the reliability distribution function of the evaluation index and the graded probability distribution of the carrying capacity of water resources are obtained by an evidential reasoning approach. Finally, the evaluation method of the carrying capacity of water resources is constructed, and specific steps are provided. The proposed method is applied to the evaluation of water resources carrying capacity for Hunan Province, which verifies the feasibility and effectiveness of the method proposed in the present study. This paper applies this method of the evaluation of the water resources carrying capacity of Hunan Province from 2010 to 2019. It is concluded that the water resources carrying capacity of Hunan Province belongs to III~V, which is between the critical state and the strong carrying capacity state. The carrying capacity of the province’s water resources is basically on the rise. This shows that the carrying capacity of water resources in Hunan Province is in good condition, and corresponding protective measures should be taken to continue the current state.


Author(s):  
DANIELLA GONZALEZ TINOIS DA SILVA ◽  
HALLEY J. BRAGA DA SILVA ◽  
FERNANDO PINHABEL MARAFÃO ◽  
HELMO KELIS MORALES PAREDES ◽  
FLAVIO ALESSANDRO SERRÃO GONÇALVES

2021 ◽  
pp. 1-18
Author(s):  
Tao Zhang ◽  
Shizheng Li ◽  
Jin Wang

China has proposed medical couplet body to alleviate residents’ difficulties in seeking medical treatment, and the future development ability of medical couplet body has gradually become a research interest. On the basis of prospect theory, this study constructs a comprehensive evaluation index system with qualitative and quantitative indexes, clear hierarchy, and diverse attribute characteristics. The development ability of medical couplet body is also comprehensively and systematically evaluated. In addition, the evidential reasoning method is proposed on the basis of the equivalent transformation of prospect value. Furthermore, the validity and feasibility of the model are proven through experiments, and the influence of decision makers’ risk attitude on the evaluation results is discussed.


Risk Analysis ◽  
2021 ◽  
Author(s):  
Xianliang Shi ◽  
Jiangning Li ◽  
Anqiang Huang ◽  
Shaohua Song ◽  
Zaili Yang

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