Research On Reliability Analysis And Maintenance Ordering Strategy Of Distribution System

With the advance of the reform process of the times,the state has invested a large number of economic,material and personnel to promote the development of rural economy.The policy of home appliances to the countryside has improved people's living standards,but it has also highlighted the problem of electricity.In recent years,the reliability of rural power supply is far lower than that of urban power supply reliability.Improving the reliability of rural distribution system is also very important.This paper mainly focuses on this issue.The main research contents are as follows:(1)From the point of view of the reliability index of users and the level of transmission and transformation facilities,this paper selects the relevant influencing factors on the reliability of rural distribution network.The grey correlation analysis method is used to analyze the correlation degree of power supply reliability.And the main factors that affect the reliability of rural distribution network are obtained.Based on the relevant data from 2012 to 2017,the power supply reliability in 2018 is predicted by using embedded grey neural network method and compared with the data in the first half of 2018 to verify the feasibility of this method.(2)The fuzzy analytic hierarchy process(FAHP)is used to set up an evaluation system of secondary indexes from the aspects of safety,failure rate,economy and maintenance.The weights of indexes are determined from the two angles of managers and technical experts,and the comprehensive scores of distribution facilities are obtained by combining with expert scoring.(3)Based on a-power process and renewal reward theory,this paper establishes the spare parts ordering strategy with limited repair time and the maintenance strategy with delayed repair equipment degradation.When the repair time is limited,the circuit breaker is the object of study.This paper considers replacement of equipment on the Nth failure.The maintenance strategy model of N-1 order reserve equipment is established,and the expression of expected cost rate is obtained.Taking the main transformer and standby transformer as an example,the maintenance strategy considering the deterioration of the delay repair equipment is proposed.Under the condition that the main transformer has priority,a mathematical model is established to obtain the expected loss expression of the system by taking the expected loss per unit time of the long-term operation as the objective function.Finally,the validity of the model is verified by numerical simulation.