The Study On The Optimal Coordination Sequence Of Directional Protection In The Multiloop Network

The relay protection setting of computer-aided calculation is the important ways and means,which is to improve work efficiency; avoid artificial defects and reduce operation costs. For sufficing the needs of computer-aided setting calculation of complex ring network, This paper analyzes the optimal setting cooperate with domestic and foreign research situation, and discusses the flow of the optimal relay protection setting calculation. On the basis of it, this article focuses on the minimum break point set to solve by using bacterial colony chemotaxis algorithem. The main content of this paper are as follows:Firstly, the paper introduces the optimal setting cooperation of each link of flow, discussed the searching of the all simple loops matrix and RSV(relative sequence vector) matrix of the directional topological graph of a network. Aiming at net topology structural characteristics, by using the graph theory, the paper constructs the maths model of nondirectional graph, then adopting the Breadth First Search method to analysis the topology graph, getting the all simple loops matrix, at the same time,this paper also introduces how to find all the P/B pairs.Then, based on the characteristics of searching MBPS, this paper improved bacterial colony chemotaxis algorithm. Introducing discrete updating mechanism, this mechanism improve to resovle the ability of a discrete problem; at the same time, this algorithm studied the algorithm diversity, improving the BCC algorithm for optimum speed and iotimization ability.Finally, in order to determine the minimum break point set of directional protection in the complex ring network, acoording to research status of the minimum break point set, this thesis introduces a new method which takes into account electric coupling paramter, number of feeders, higher speed protection and important loads as judging the criterion. Establishing the mathematical model of seeking minimum break point set. Based on bacterial colony chemotaxis algorithm, this paper puts forward a new method of seeking minimum break point set. Through the analysis of the example proved , it not only can find all the minimum break point set, but also can quickly find optimal minimum break point set.