Research On Reliability Evaluation Method Of Distribution Network

With the rapid development of economy,people’s living standard is improving day by day.Since the distribution system is directly connected to the transmission/transmission system and power users,it has a significant impact on the power supply reliability of users.According to statistics,more than 80% of power failure in the power system is caused by the failure of the distribution system;Therefore,scientific and reasonable reliability evaluation of distribution system is of great significance to improve the reliability of power supply.This paper at first introduces the background and significance of power distribution system reliability evaluation,describes the reliability evaluation of distribution system development present situation at home and abroad,and to our country puts forward some Suggestions for further development of the power distribution system,and analyzes several reliability evaluation method of existing contrast,points out their advantages and disadvantages and applicable scope;This paper introduces the connection mode and operation characteristics of distribution system,introduces the reliability index of distribution system and its reliability evaluation model,and gives the corresponding calculation formula of reliability index.For complex distribution system reliability evaluation difficult,large amount of calculation,calculation time is too long,this paper proposes a network,with the method of equivalent method and quasi monte carlo simulation method is applied to the reliability evaluation of distribution system,the method is first used network equivalent method of equivalent upward and downward to simplify the distribution network equivalent to a simple equivalent radial main feeder system,with a quasi monte carlo simulation method for simple radial main feeder system was simulated to obtain the various distribution systems reliability index;Meanwhile,in view of the problem that the reliability index cannot reflect the true reliability level of the distribution system in the reliability evaluation of the distribution system,the reliability level of the distribution system is evaluated by combining the probability distribution of power failure times and power failure time with the original reliability index of the distribution system.Based on the IEEE RBTS bus 6 main feeder 4 distribution system to validate the proposed method,based on the method and analytic method,the calculation of reliability index results and the computing time of monte carlo simulation method,this paper compares and analyzes proved the accuracy of the proposed method in this paper,at the same time the method gains power frequency and power outage time probability distribution is analyzed,and points out its significance in distribution system reliability evaluation;Finally,in order to verify the feasibility of the method presented in this paper in the actual distribution system,the feeder F2 of a 10 kv substation in a city was selected as an example for analysis,and the feasibility of this method was proved by calculation results.