complex distribution networks;  reliability assessment;  interval algorithm;  Network equivalence

A method for evaluating the reliability of complex distribution network using interval algorithm is proposed. In order to simplify the network, according to the characteristics of complex distribution network, the network equivalent method is used to obtain a simple radial network by carrying out upward and downward equivalence processes. The algorithm analyzes and processes the original reliability parameters of the components of the distribution system, obtains the original interval parameters of the reliability of each component, and obtains the reliability interval index of the load point and the system and the economic loss interval value of the power outage. The reliability evaluation of RBTS-BUS2 system is carried out by applying the algorithm, and the results show that the algorithm is flexible, efficient and has engineering practical value.