| With the continuously development of the scale of power grid,electric networks is intensifying,short-circuit current is consequently increasing year by year,which has become a serious problem for the planning and operation of power system.How to select optimal short circuit current limiting strategies in power systems,which limit the fault current under a reasonable value as well as safety and economical operation in power network has been one of the most urgent affairs.Based on analyzing and comparing the basic principles and traits of the different methods of limiting short circuit current,also researching the mathematical model,application characteristics,usability and effect,the paper discusses the different ways as a whole to limit the fault current on the different stand points.In this paper,an optimization algorithm by fuzzy comprehensive evaluation is proposed.Based on the model of multi-step fuzzy comprehensive evaluation,the fuzzy behavioral indicator and membership degree indicator are researched,for the optimization objective of economy, security and reliability power grid operation,an evaluation methodology for allocating optimal short circuit current limiting strategies in power systems is presented.Finally,the object of computing and analysis of this article is to the North China power grid in the programming level year. Through the calculation and analysis on various methods to limit short-circuit current of the North China power grid,three fessible short-circuit current limiting strategies are proposed.Using the evaluation methodology for allocating optimal short circuit current limiting strategies that is based on the model of multi-step fuzzy comprehensive evaluation,the evaluation methodology datamaprepository the priority of comprehensive evaluation and definite optimize proposal.The feasibility of the method proposed is verified by the simulation results of North China power grid and proved its effectiveness.
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