| With the expansion of the power grid and the increasing degree of network-to-network connectivity,increasing short-circuit current levels are becoming more of a serious threat to systems and equipment.The threat posed by excessively high short-circuit current levels will surely become a major flaw in the subsequent development of the power grid.Under this circumstance,the current limiting measure is a problem that must be considered in the power grid planning stage.Installing the fault current limiter is the first choice for the equipment-level short-circuit current over-standard suppression strategy at this stage.With the development of superconducting materials and their control technology,superconducting fault current limiters(SFCL)have become the focus of research because of their advantages in current limiting effect and speed of action.Due to the multi-point problem in the power grid,considering the high cost of SFCL,the global configuration method of current limiting by the coordinated action of the installed current limiter is generally adopted,which can minimize the configuration of the fault current limiter while ensuring the current limiting effect cost.For economic planning and configuration of longterm equipment such as SFCL,it should not only consider its initial configuration cost,but also consider its full life cycle cost-product equipment within its useful life,including input,operation and maintenance,etc.The sum of all costs.For the configuration problem of SFCL,this paper incorporates the optimal cost of life cycle as the new economic cost checking target,and further considers the SFCL action threshold setting,and proposes corresponding research ideas and solutions.This paper first briefly introduces the current situation of severe situation of shortcircuit current exceeding the standard and the whole implementation of life cycle planning in engineering planning.According to the response characteristics of SFCL and its configuration characteristics,the SFCL life loss model based on the inherent fatigue life of the material is constructed.Based on this,the life cycle cost calculation method based on the cost of installation,loss and maintenance is proposed.Based on system parameters and expert experience,the Monte Carlo simulation probability model considering the influencing factors of short-circuit current level—fault line,fault location,fault type and system operation status is analyzed and constructed for fault simulation and life calculation of SFCL.Then,this paper constructs a Pareto optimal configuration model that satisfies the constraints of current limiting and the global acquisition and installation cost as the objective function,and obtains the optimal set of basic configuration schemes.Through the Monte Carlo fault simulation based on the target system based on the SFCL in the basic solution,the action behavior of SFCL is evaluated,and the value loss and life are analyzed.Through the life cycle cost analysis of the process,the basic The configuration plan focuses on the optimal SFCL configuration scheme at full cost of life.Finally,the relationship between the SFCL action threshold and its lifetime loss is discussed.Considering the setting of the SFCL action threshold,the efficiency of SFCL is further improved.Based on the original cost function,the new life cycle cost function is obtained by considering the cooperation between SFCL replacement and grid planning period.On the basis of the obtained Pareto basic configuration scheme,the basic installation plan location is used as the basis for quantification,and the action threshold and current limiting capacity are optimized,and the basic configuration scheme is matched with the grid planning period.The threshold setting method and current limiting capacity,and then the optimal life cycle cost screening of each scheme is carried out,and the SFCL life cycle cost allocation scheme considering the threshold difference setting is obtained. |
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