摘 要 由于当今经济建设的发展日新月异，能源需求与日俱增，而化石能源储量趋于枯竭状态，核能的发展由于对生态环境的威胁而受到一定的限制，迫于能源和环境危机带来的巨大压力，开发和利用新兴能源成为当务之急。于是，作为可再生能源的分布式电源（Distributed Generations,DG）的兴起给当前严峻的形势带来了极大的转机。由于DG具有高效、清洁、灵活等特点，DG的出现受到了广泛的关注，其在配电网中的渗透率也越来越高。但是当DG接入配电网后，导致配电网的网架结构、潮流及短路电流都发生了变化，这将对配电网原有保护的可靠动作造成严重的影响。 为了解决DG接入配电网后带来的一系列保护方面的问题，本文首先对DG的种类及特点、数学模型、入网方式以及并网仿真模型做出了介绍。然后针对含DG的配电网的结构特点，提出分割区域的概念，并且对含DG的配电网进行拓扑分析及图描述，进而根据故障前后综合电流的变化情况对分割区域的故障特性进行了详细地理论分析。 通过对分割区域故障特性的分析，发现故障后分割区域综合电流的方向不唯一，无法对故障区域定位，因此提出了边电流变化量保护方法。边电流变化量保护方法是根据故障前后有向边的边电流方向及幅值的变化情况来判断有向边的起点区故障还是终点区故障，从而实现对故障区域的定性判断。 为了对故障区域定量判断，根据边电流变化量保护方法提出了基于边故障信息值的故障定位算法，但是通过边故障信息值对故障区域的判断并不直观，因此提出了基于区域故障信息值的定位算法。完成了分割区域的故障定位之后，根据断路器的实时开合状态提出了基于断路器状态信息值的故障隔离算法，实现故障区域的可靠隔离。 以上各个环节相互配合形成了完整的含DG的配电网自适应保护策略。最后运用PSCAD/EMTDC搭建了含DG的配电网的仿真模型，通过仿真结果验证了自适应保护方法的有效性。

Abstract Because of the rapid development of economic construction and increasing energy demand, fossil energy reserves tend to be exhausted, and the development of nuclear energy is limited by the threat to the ecological environment. Therefore, it is urgent to develop and use emerging energy due to the pressure of energy and environmental crisis. Distributed Generations (DG), as a rising renewable energy, has brought great changes to the current severe situation. Because DG has the characteristics of high efficiency, cleanliness and flexibility, the appearance of DG has been widely concerned, and its permeability in distribution network is also increasing. But when the DG is connected to the distribution network, the structure, power flow and short circuit current of the distribution network have changed, which will seriously affect the reliable action of the original protection of the distribution network. In order to solve a series of protection problems caused by the DG access to distribution network, this paper firstly introduces the types and characteristics of DG, the mathematical model, the way of network entry and its simulation model. Then, according to the structural characteristics of the distribution network with DG, the concept of the segmentation area is put forward, and the topology analysis and graph description of the distribution network with DG is also presented. Moreover, according to the change of the comprehensive current before and after the fault, the fault characteristics of the segmentation areas are theoretically analyzed in detail. Through analyzing the fault characteristics of the segmentation area, it is found that the direction of the comprehensive current in the segmentation area is not unique, so the fault area can not be located. Therefore, this article offers a protection method to the variation of side current. It is to judge the fault of the starting point or the terminal area of the directional side according to the change of the direction and the amplitude of the side current of the directional side before and after the fault, so as to realize the qualitative judgment of the fault area. In order to judge the fault area quantificationally, the fault location algorithm, based on the fault information value of side, is proposed according to the protection method of the variation of side current, but the judgment of the fault area is not intuitionistic by the fault information value of side. Therefore, a location algorithm based on the regional fault information value is proposed. After the fault location of the segmentation area is completed, the fault area needs to be isolated reliably. According to the real-time opening and closing state of breakers, a fault isolation algorithm based on the status information value of breakers is proposed to achieve reliable isolation in the fault area. The above links cooperate with each other to form a complete adaptive protection strategy of distribution network with DG. Finally, the simulation model of distribution network with DG is built by PSCAD/EMTDC, and the effectiveness of the adaptive protection method is verified by the simulation results.