不换位线路参数不对称对距离保护的影响分析

Analysis of line asymmetry parameters' impact on distance protection considering the untransposed transmission line

不换位输电线路的参数不对称性,将会影响到基于参数对称为前提的保护的正确动作。为了研究参数不对称对于距离保护的影响,提出了不换位线路的序参数计算方法。在此基础上,通过理论推导和数字仿真,分析了阻抗继电器在各种故障情况下,不换位线路的测量阻抗的误差大小。据此,对不换位线路的距离保护整定计算提出改进建议。

The asymmetry of untransposed transmission lines parameters will affect the correct operation of protection which is based on parameters symmetry. To study the line asymmetry parameters’ impact on distance protection, this paper puts forward the sequence parameter calculation method of untransposed lines. On this basis, it analyzes the error of untransposed lines measured impedance through theoretical derivation and numerical simulation, when the impedance relay is in various fault cases. In response to the measured impedance errors of untransposed lines, improvement suggestions of distance protection setting are put forward.