含风场的多分布式电源接入配网线路保护的研究

Protection for distribution network lines connected with multi distributed generations containing wind farm

分析了含分布式风场的多分布式电源的配电网支路故障电流特性,对故障定位矩阵算法进行改进优化。该方案对含分布式电源支路进行改进,首先采用故障正序和负序分量幅值之和初始突变量来定位故障相关区域,其次通过比较线路两侧电流幅值变化特性来定位故障。对综合幅值判据进行简化,在实际中采取对含分布式电源支路保护方案进行改进,其他支路保存不变方式减少了设备、节约成本,并且可以定位故障区段。在PSCAD/EMTDC平台上搭建配网模型,在对称及不对称负荷情况下对保护算法进行验证,试验结果证明方案的有效性。

Based on the analysis of fault current characteristics of distribution network branch with Dt.j, matrix algorithm for fault location is optimized. The branch contained with distributed generations is improved. To begin with, fault associated area is located by the initial mutations quantity from sum of positive-sequence component and negative-sequence component rms. What＇s more, fault line is located by comparing both sides of the line current amplitude variation characteristics. Comprehensive amplitude is simplified, protection scheme is improved for distributed generations branch, and other branches remain unchanged in order to reduce equipment, keep cost saving, and locate fault line. The typical model is built on PSCAD/EMTDC platform for proving the protection algorithm in both symmetric and asymmetric fault. The simulation results of different fault type results show the effectiveness of this scheme.