【摘要】 针对小电阻接地系统发生单相高阻接地故障时存在的保护死区问题，依据接地线路与正常线路零序电流相位存在明显差异的特点，提出一种基于余弦距离和DBSCAN聚类的小电阻接地系统选线方法，通过计算馈线零序电流余弦距离矩阵并结合DBSCAN聚类算法实现选线。对于工程中零序电流互感器极性错误，通过对零序电流进行预处理，进一步提高选线的可靠性。通过仿真验证所提方法在单相高阻接地、谐波干扰、零序电流互感器极性错误、同相两点接地、母线接地等情况下能可靠选线。更多还原

【Abstract】 Aiming at the problem of protection dead zone in the case of single-phase high resistance ground fault in low resistance grounding system, according to the clear difference between the grounding line and normal line in phase of zero sequence current, a line selection method based on cosine distance and DBSCAN clustering for low resistance grounding system is proposed. The line selection is realized by calculating the zero-sequence current cosine distance matrix of the feeders and combining with the DBSCAN clustering algorithm. For the polarity error of the zero-sequence current transformer in the project, the reliability of line selection is further improved by preprocessing the zero-sequence current. Through simulation, it is verified that the proposed method can reliably select the line under the conditions of single-phase high-impedance grounding, harmonic interference, zero-sequence current transformer polarity error, non-inverting two-point connection, and bus bar grounding.更多还原