Distribution System Reliability And Economic Assessment

Reliability and economy are the most two important index of Power System, but also contradictory to each other.In the distribution network planning and reconstruction, how to take into account the both impact of reliability and economy, how to coordinate the conflict between them, and how to use limited funds to maximize the increase of the reliability of the system has great significance.This paper firstly summarizes the distribution network reliability evaluation methods, focuses on the evaluation method based on the RAMSES. By using "power customer interruption cost" to quantify the economic value of reliability , and considering investment,operating costs, loss and other costs, this paper brings forward the concept of "comprehensive cost",and establishes a comprehensive evaluation model of the distribution network considering both reliability and conomy.This paper summarizes the common typical grid pattern of the distribution network, and evaluates their reliability. This paper also establishes a comprehensive evaluation model which is suitable for the analysis of the typical grid pattern. Considering two types-the overhead line and cable line, eight kinds of topical pattern are analysed, and a number of general conclusion will be reached on the basis of the simplification.This paper will also applies the comprehensive evaluation model to the problem of the selection of the distribution transformer.Considering load density as a breakthrough, this paper advances a new idea and appropriate mathematical model, and through actual examples showes the effect of the method. The important impact of load characteristics and parameters related to the problem is also be analysed.Finally, considering the variety and complexity of the actual distribution network, an evaluation and optimization software integrating the reliability and economy is designed.The modeling,loss calculation of the power gird and such key technologies are introduced.And through examples, the actual distribution network and its transformation programme are analysed using the comprehensive evaluation model considering both reliability and economy.