中文摘要：

针对有名制纵向阻抗在短距离线路保护时存在甄别裕度不足,在不同的因素干扰下缺乏一致比较基准等所暴露出来的技术缺陷,根据标幺制潮流计算的建立原则和推广意义,提出一种标幺制纵向阻抗的计算方法.此方法继承了标幺制潮流计算的全部优势.通过在EMTP仿真环境下构建完全相同的输电线路模型以及相互对应的线路分布参数,进行了对比性的仿真验证.仿真结果证实标幺制纵向阻抗可以有效克服上述缺陷,因此理论分析与仿真验证证实了所提计算方法的工程实用价值.

英文摘要：

According to the technical defects of the longitudinal impedance（LI）,based on the establishing principle and the application value of unit system,the calculation method of the LI based on the per-unit system is put forward.This method is inherited all advantages of the per-unit system power flow calculation.The completely identical transmission line model and the mutually corresponding line distributed parameters are constructed on EMTP simulation environment and the comparative simulation experiment is carried out.The simulation results provide the fact that the LI based on the per-unit system can effectively overcome the above technical defects,thus the practical engineering value of this calculation method are confirmed by the results coming from the theoretical analysis and the simulation verification.