中文摘要：

提出中压配电网的可靠性评估级别树算法。考虑到中压配电网故障隔离、修复和切换等过程，以及开关动作特性，提出开关树、断路树2种可靠性级别树的概念和形成算法，进而将配电网等值为等效的开关树、断路树。采用动态链表模型存储可靠性级别树信息以减少冗余存储，降低存储复杂性。计及设备故障、备用切换等对负荷点可靠性的影响，基于可靠性级别提出统一的负荷点可靠性指标计算模型。由于可靠性级别树具有简化配电网的特性，且计算过程中只使用上行搜索方式，算法具有较高的计算效率。利用该算法对RBTS测试系统、某地区的10kV配电网进行了可靠性评估。分析结果表明该算法可用于传统中压配电网和接入新能源后的中压配电网的可靠性评估。

英文摘要：

A reliability evaluation algorithm for medium voltage distribution networks is proposed. Considering such processes as fault isolation, fault restoration and power source switching-over in medium voltage distribution networks as well as the action characteristics of switching-device （SD）, the concepts of reliability level tree for SD and circuit breaker as well as the algorithm to form the two kinds of trees are presented, and then using the proposed forming techniques a medium voltage distribution network can be equivalent to a SD tree and circuit breaker tree. A dynamic linked list is adopted to store the information of reliability level trees to reduce redundancy storage and storage complexity. Taking the influences of equipment failures and standby switching-over on reliability of load point and so on into account, based on reliability level a unified model to calculate reliability indices of load points is given. In view of the fact that the reliability level trees possess＂ the features of simplified distribution network and during the calculation only seek up mode is utilized, the proposed algorithm is efficient. Applying the proposed algorithm, the reliability of RBTS system and a 10 kV distribution network in a certain region are evaluated. Analysis results show that the proposed algorithm can be used for reliability evaluation of traditional medium voltage distribution network and the reliability evaluation of medium voltage distribution network after new energy is connected to it.