目前，大量分布式电源与不可测负荷分支接入配电网，原有保护方案不能满足新型配电网需求。通过分析含不可测负荷分支的有源配电网的不对称故障特点，建立区内、外负序故障附加网络等值模型。分析所得等值模型，提取出被保护线路在区内、外故障下不同的模型表达，以此设计基于模型识别的保护判据，构造一种基于负序故障附加网络模型识别的保护方案。利用PSCAD仿真软件搭建10 kV有源配电网模型，对所提方案进行验证。结果表明所提方案能准确实现故障区域识别。

Nowadays, a large number of distributed power sources and unmeasurable load branches are connected to the distribution network, and the original protection scheme cannot meet the requirements of the new distribution network. By analyzing the asymmetric fault characteristics of active distribution network with unmeasurable load branches, a negative sequence fault superimposed network equivalent model inside and outside the area is established. By analyzing this equivalent model, the different model expressions of the protected lines under internal and external fault are extracted to design protection criteria based on model identification. A protection scheme based on the negative sequence fault superimposed network model identification is designed. A 10 kV active distribution network model identification is built by using PSCAD simulation software to validate the proposed scheme. The results show that the scheme can accurately identify the fault area.

国家自然科学基金项目（52107098）；江苏省研究生实践创新计划项目(SJCX21_0944)