Research On The Equivalent Algorithm Of Reliability Evaluation For Complex Power Distribution System

It is difficult to analyze the distribution system reliability because it has lots of equipment and connection modes, operation mode is also varied. The previous reliability algorithms consider single failure mode, some methods are not suitable for large and complex distribution system. In order to analyze the reliability of large-scale distribution system under various operating modes and system load, this thesis aim at radial connection modes of medium voltage distribution system commonly used, having done the following work:Proposed a equivalent algorithm that combining stratification, minimal path method and the equivalent, considering alternate wiring、 fuse connected to the load side, standby power, etc. It is suitable for reliability index evaluation of complex distribution system.In this method, various components of the system using the two-state model and the search based on the hierarchical method. The hierarchical method search from the end of the complex distribution system, layers up search traversal method using a minimum equivalent to become the main trunk road layer, distribution system reliability indices derived trunk load of all the components in case of failure, then down the search to traverse layers, using minimal path method eventually get all the reliability index component failure when all loads, and finally get the system reliability index based on the calculated reliability index of the system.Using C++language program and the method is tested by IEEE RBTS Bus6system. The program running to get the reliability index of each load and the system under a variety of operation and failure modes. Comparing with the results of reference shows the correctness and reliability of the algorithm. The result of calculation has reference value for the distribution system operation, planning maintenance, operation mode selection, etc.