量测误差对高压线路零序参数辨识的影响机理分析

摘要

输电线路的零序参数是电力系统分析计算、保护整定的重要参数.随着PMU的广泛应用,采用PMU量测数据在线辨识成为输电线路零序参数获取的新方法.然而,现场PMU量测数据往往存在误差,影响了零序参数计算结果的精度.该文在输电线路π模型的基础上,分析了三相电压、电流相量量测误差对输电线零序参数辨识的影响机理.首先,通过数学推导,揭示了三相量测误差对零序分量的影响;其次,采用小扰动分析方法,研究了零序电压与零序电流的幅值、相角影响零序参数计算结果精度的机理;最后,通过仿真验证了所提理论的正确性.%The zero-sequence parameters of transmission line are important parameters of power system analysis and pro?tection setting.With the wide application of phasor measurement unit(PMU),there is a new way to online identify the zero-sequence parameters of transmission line using PMU measurement data.However,there always exist errors in the in situ PMU measurement data,which affect the precision of calculation result of zero-sequence parameters. Based on theπmodel of transmission line,the influence mechanism of three-phase voltage and current phasor measurement error on the identification of zero-sequence parameters of transmission line is analyzed.Firstly,by mathematical derivation, the influence of three-phase measurement error on zero-sequence component is analyzed;secondly,the influence mecha?nism of the amplitude and angle of zero-sequence voltage and current on the precision of parameter identification is stud?ied by using small perturbation analysis method;finally,the proposed theory is verified through simulation .