Study On The Rapid Evaluation And Prediction For The Reliability Of The Urban Medium Voltage Distribution Networks

Prediction of power supply reliability plays an important part in design, construction and operation management of power system. This paper has focused on the reliability and accomplished the study on the rapid evaluation and prediction for the reliability of the urban medium voltage distribution networks.Based on the AutoCAD visualization platform, and using Visual Studio.NET, ObjectARX secondary development technique and large-scale database, the author has completed the design and implementation of reliability evaluation module under the graphical interface applications. A general reliability evaluation algorithm for complex medium voltage distribution networks (MVDNs) is proposed, in which each feeder is a basic unit and without simplifying the network equivalent, the depth-first search algorithm and breadth-first search algorithm are used to search each feeder in topologies. Then circuit breakers oriented first-class zone based on the same influences by the failure and isolating switches oriented feeder second-class which is also the minimum zone based on causing the same failure impact are formed. System's normally power supply area, system's operational recovery of power supply area and system's unoperational recovery of power supply area can be formed by each at one time. The module has been tested on the practical MVDNs to calculate the system reliability index quickly.A grid structure based method to predict power supply reliability for complex distribution networks is proposed in this paper. By principal component analysis of grid structure, the dimension of input prediction variables is reduced and the prediction accuracy is improved. The method has been tested on the practical distribution networks of a certain city, which verifies the effectiveness and the practicability of the proposed methods and applications in practical engineering.