含分布式电源的配电网智能电流保护策略

以含有多分布式电源(distributed generation，DG)的配电网为模型，提出一种基于多智能体(Agent)的新型分布式电流保护策略。该策略以简单的工频电流比较为基础，运用智能体的分布式处理优势，实现对故障的在线搜索和定位。阐述了利用工频电流变化量幅值和相位比较法进行故障区域搜索、故障线路判定的原理：首先利用DG接入形成的T型节点判断故障搜索的正方向，确定一个较小范围的故障搜索区域；然后通过比较线路两端故障电流幅值或相位确定故障发生的最小区域，并最终完成故障隔离。文章在多智能体分布式处理与主动协作的基础上，提出了分布式电流保护的基本框架和算法流程，并在含有2个DG的配电网模型上进行了仿真验证，仿真结果证明了保护算法的正确性。该保护策略对分布式发电条件下配电网网络结构和运行方式的随机变化具有良好的适应性。

An Intelligent Current Protection Strategy for Distribution Network Containing Distributed Generation

A multi-agent based new distributed current protection strategy for distribution network containing distributed generation (DG) is proposed. Based on simple comparison of power frequency currents and using the superiority of distributed processing of multi-agent the proposed protection strategy implements on-line searching and location of faults. The principles of searching faulty region and determining faulty line by use of the amplitudes of power frequency current variations and phase comparison method are as following: at first, the T-shape nodes where the DGs are connected into distribution network is used to judge the positive direction of fault search, so a smaller fault search range can be determined; then comparing the amplitude or phase of fault current at both ends of the transmission line the minimum region where fault happened is determined so that the fault can be isolated finally. On the basis of distribution processing and proactive collaboration of multi-agent, the basic framework and flowchart of corresponding algorithm are put forward and verified by the simulation of a distribution network model with two DGs. Simulation results show that the proposed protection algorithm is correct. The proposed protection strategy can adapt to the random variation of the structure and operation condition of distribution network containing DGs.