Study On Maintenance Decision Of Power Transformer Based On Life Cycle Cost

The power transformer is the pivotal equipment in the power grid system.The normal operation of the transformer has a great influence on the stable operation of the power system.In recent years,the reliability and safety requirements for power supply in industrial production and people's life are gradually improved,and various input costs for transformers are also increased at the same time,and the contradiction between the growing demand for high-quality electricity and the limitation of funds is becoming increasingly apparent.Therefore,it is necessary to study the life cycle cost and maintenance decisions of power transformers.At present,the research on the life cycle cost and the maintenance decision of transformers mainly focus on the situation of overhauling twice,the age reduction factor is a fixed value,the impact of minor repair on the age reduction and the failure rate are not taken into account,and some of parameters of the transformer are set to certain values.So there is a certain error between the calculation result and the actual value.In response to the above issues,main contents of the paper include:(1)First,the cost components of the power transformer in different life stages are analyzed.Second,the factors affecting the life cost(including the failure rate,the equivalent service age,maintenance method,etc.)and the data of the power transformer in each operation stage(including the purchase cost,the load rate,parameters of maintenance and decommissioning,etc.)are collected.The impact of overhauls and minor repairs on the age regression and the failure rate are analyzed.The dynamic age reduction factor is considered,that is,the age reduction factor gradually decreases with the increase of the number of maintenance,and at the same time,impacts of minor repairs on the age reduction and the failure rate are considered.Finally,the life cycle cost model of power transformer is built.(2)The double Latin Hypercube Sampling is performed on the parameters of the transformer depending on the doubly stochastic and the triangular distribution,so that the parameters of the transformer are more closer to the real value.And the model of life cycle cost of the transformer is applied to transformer capacity selection,a cost probability distribution histogram is obtained through by Monte Carlo.(3)The cuckoo search is improved by combining adaptive strategies of step-size factor and parameter Pa.And the improved cuckoo search is applied to optimize the life cycle cost model.Ultimately the optimal overhaul time and the corresponding life cycle cost are determined.(4)The maintenance decision-making interface of the transformer based on life cycle cost is designed using the platform of MATLAB Graphical User Interface(GUI),including the estimation interface of life cycle cost of transformers based on the double random variables,the transformer selection interface based on the double random variables and LCC,the power transformer maintenance decision interface based on the adaptive cuckoo search.