Maintenance Strategy Of Power Transformer Based On Risk Assessment And Cost Analysis

The power transformer is the core equipment in the power system,and its safe and stable operation is the basic condition for building a strong power grid.Grid companies have invested a lot of manpower and material resources in the maintenance of power transformers to ensure the safe and stable operation of the transformers.However,the excessive maintenance and the waste of funds caused by the one-sided emphasis on reliability are becoming more and more serious.Therefore,it is necessary to take into account the reliability and economy of power transformer operation,By analyzing the risk benefits and life cycle costs of power transformers during operation,reasonable maintenance plans are formulated to promote power companies to further improve the quality and efficiency of asset management capabilities.Therefore,this article discusses and researches the power transformer maintenance decision based on risk assessment and cost analysis.The main research work is as follows:(1)According to the state evaluation standards,the fitting curve of failure rate and the related theories of service age regression in the "Test Procedures for Condition Maintenance of Transmission and Transformation Equipment",the probability of failure before and after the three maintenance programs of power transformer overhaul,minor repair and live overhaul is obtained model.And according to the theory of life cycle cost,the life cycle cost model of overhaul,minor repair and live maintenance is constructed.(2)In view of the correlation among parameters in the transformer Life Cycle Cost(LCC)model,a system dynamics model based on power transformer LCC was established in this paper based on the theory of system dynamics.From the perspective of the system,the model fully considers the comprehensive influence of various factors on the change trend of LCC,so that the estimation is closer to the reality,and the key parameters affecting the change trend are extracted.At the same time,the LCC and the equivalent annual recovery cost under the three maintenance modes are obtained.(3)The transformer risk assessment model is established by combining the failure rate before and after the transformer maintenance with the possible loss of assets,and the severity of the consequences of the current transformer failure is clear.At the same time,the risk level is divided according to the minimum reasonable feasibility principle(ALARP),and the risk level of the transformer is quantified;According to the calculation of the risks before and after maintenance,the risk benefits of power transformers under different maintenance strategies are calculated.(4)In order to comprehensively consider the technology and economy of power transformer maintenance strategy,a risk assessment and cost analysis model of power transformer is established,which takes into account the equivalent annual recovery cost and risk benefit.The cost effectiveness of the three maintenance methods of power transformer is taken as the evaluation index for the formulation of maintenance strategy.Through this model,the risk and cost of the maintenance can be effectively combined,so that the technical and economical integration of the maintenance strategy during the life cycle of the transformer is optimal.Finally,an example is used to verify the effectiveness of the proposed model.