Optimal Operation And Maintenance Decision Of Relay Protection Devices Based On Life Cycle Cost

In recent years,with the structural reform of the supply side advancing the rapid development of the State Grid,the scale and operation technology of the power grid have been continuously expanded and innovated,and the operating mechanism and characteristics of the power grid have become increasingly complex.The relay protection device is the first line of defense for the power system.It is imperative to arrange reasonable overhaul decisions.The rationality of the maintenance of relay protection devices is closely related to the power company,the interests of users and the safety and economy of the society.Therefore,how to better arrange the maintenance strategy of relay protection devices is very important in the operation of the power grid.This paper analyzes the current status of the operation and maintenance of the protection device in the power grid,and mainly studies how to develop a reasonable preventive maintenance strategy for the protection device.Firstly,different failure mechanisms of relay protection devices are distinguished.Different distribution functions are used to describe the failure rate during different failure mechanisms,and four different distribution functions are used for fitting the failure rate during aging failure.The optimal distribution function builds the failure model.Secondly,the maintenance project of the relay protection device is analyzed,and the service age regression factor is introduced as the link between the maintenance and the device failure.The service age regression factors under different preventive maintenance modes are distinguished,and different preventive measures are respectively The value of the age-return factor in the maintenance mode is studied in depth.Then,based on the life-cycle cost factor,based on the life-cycle regression factor,the maintenance decision-making model of the relay protection device with the long-term total cost optimization as the target and the maintenance mode and maintenance time as variables is established.Considering the degree of importance of the protection devices in the power grid,four constraint decision-making schemes are proposed to make the maintenance decision more reasonable.Finally,the maintenance decision model established in this paper is a multi-extreme function,so the hAG hybrid algorithm is used to solve the model.The algorithm has better stability and stability for solving complex problems.In this paper,the hAG hybrid algorithm is used to solve the maintenance decision model of the protection device under different demand conditions,and the rationality and effectiveness of the model and algorithm are verified.