Reliability Evaluation Of Distribution Network Based On Equivalent Network

The purpose of study on distribution system reliability is to improve the power supply ability and power quality. With economic development and the load increased, distribution network reliability problem has become more and more important in production and management of electricity sector. In particular, the reliability evaluation has become a regular part in network planning and decision-making.First, the paper introduces the status and trends of reliability study at home and abroad, and gives comprehensive analysis of various evaluation methods of distribution network. Then it simplifies the component model moderately and proposes the statistical method of the component original parameters.The paper put forward a reliability evaluation method based on equivalent network after comprehensive analysis and in-depth study on relevant literatures of equivalent method. It not only inherits the basic ideal of equivalent network, but also makes important improvements on the key aspects of equivalent process. With the definition of the minimum fault zone, the equivalent regions are divided subsequently. And the data structure based on the minimum fault zone has much less workload of data storage than the data structure based on the node. Furthermore, the way of taking the minimum fault zone for equivalent unit simplifies the calculation to a great extent. Accounting the line capacity constraint, this paper derives a complete set of formulas by taking equivalent data as parameters.In the premise of meeting precision requirement, the paper proposes the operational conditions of reliability evaluation, and makes reliability evaluation on actual distribution line. It shows the accuracy and efficiency of the improved method. Then it makes the reliability level clearly and the weak links exposed by analyzing the relationship between component reliability and system reliability and quantifying the reliability level of various wiring methods. Finally, this paper introduces some management and technical measures, which can play a good role in improving the reliability of distribution system.