Research On Evaluation Method Of Power Grid Operation Index Based On AHP-Gray Relation Analysis

The Electric power system is a power production and consumption system that is composed of power generation,power transformation,power transmission,power distribution,and power consumption.The operation status of electric power system has a great impact on people's production and lives.With the extensive use of clean energy,energy storage devices and electric vehicles,and the continuous increase in people's requirements for power supply services quality,new requirements have been put forward for their operation evaluation.Therefore,it is necessary to build a suitable evaluation index system for power grid operation and develop corresponding evaluation methods.The index system constructed in this thesis comprehensively considers multiple stakeholders including power generation companies,power grid companies and power users.It takes economy,cleanliness,safety,fairness and power supply services quality as the first-level indicators.The corresponding secondary and tertiary indicators are given,which is based on the interest of the stakeholders.Also,the thesis introduce the definition of the indexes,and the applicable time range;it put forward the power generation coal price ratio index of the power generation company and give the corresponding calculation formula.In terms of evaluation methods,the analytic hierarchy process(AHP)method is used to determine the initial weights,and the influence of the weights under different preferences on the evaluation results is considered.In addition,considering the influence of the correlation between indicators on the evaluation results,the gray correlation and threshold variable weight methods are firstly used to adjust the initial weight determined by the AHP method to eliminate the correlation between the indicators.Then the thesis build an optimization model to obtain the ? fuzzy measure,and finally use the chouqet fuzzy integral to aggregate the index score to obtain the final comprehensive score.The calculation use the operational data generated from a grid in 2013-2017 for simulation experiments,and the experimental results show that different preferences have different sensitivity to the volatility of the data and produce different evaluation results,verifying the effectiveness of the proposed method of removing the correlation of indicators,which can not only show the positive or negative correlations between the indicators,but also show the stronger sensitivity to the fluctuations in the data.The score results are more suitable for the actual operation of the power grid.In addition,this thesis further considers that the process of determining the initial weights by the AHP method is due to the expert's given judgment matrix,which will bring about the problems of excessive subjectivity and ambiguity,and affect the rationality of the determined weights.Also,considering the disadvantage that the use of entropy weight method may lead to a certain index weight is too large,the thesis uses the combination of fuzzy analytic hierarchy process(FAHP)method and improved entropy weight method to determine the initial weight.Furthermore,the data of China Southern Power Grid is used in the simulation experiment.The experimental results show the superiority of the method,the weight is more reasonable and the fluctuation of the data is further strengthened sensitivity.Finally,the fuzzy dynamic analytic hierarchy process(FDAHP)is used to depict the change of index weights with time.