考虑相量量测单元数据不同步的双端输电线路正序以及零序参数辨识方法

Identification of Positive Sequence and Zero Sequence Parameters of Double-ended Transmission Lines Considering Phasor Measurement Unit Data Asynchrony

针对相量量测单元(phasormeasurementunit,PMU)数据不同步导致参数辨识结果误差大的问题,提出了考虑PMU数据不同步的输电线路正序以及零序参数辨识方法。首先,分析线路集中参数模型和分布参数模型在一定电压等级下的长度适用范围。基于线路的集中参数模型,利用正常运行情况下PMU装置获取的线路两端功率以及电压信息,构建以正序参数和不同步角度为未知量的非线性方程,并运用Levenberg-Marquardt(L-M)算法求解正序参数以及不同步角度。其次,在辨识出正序参数以及不同步角度的基础上,分析单相接地故障情况下的正序、负序以及零序等效电路图,通过正序和负序网络求解出故障距离。在故障距离已知的情况下,基于零序网络构建以零序参数为未知量的方程,并利用L-M算法求解方程。最后,利用MATLAB软件搭建单回双端输电线路系统,并对所提正序以及零序参数辨识方法进行仿真,验证了所提参数辨识方法的有效性和精确性。

Regarding the problem that the phase measurement unit(PMU)data are not synchronized,which leads to significant mistakes in the parameter identification results.Considering the PMU data are not synchronized,this paper proposes a method to identify the positive sequence and zero sequence parameters of transmission lines.Firstly,the applicability range of the centralized and distributed parameter models of the line at certain voltage levels is analyzed.Then,based on the centralized parameter model of the line,using the power and voltage information at both ends of the line obtained by the PMU device under normal operation,a nonlinear equation is constructed with the positive sequence parameters and the asynchronous angle as unknown quantities,and the Levenberg-Marquardt(L-M)algorithm is applied to solve the positive sequence parameters and the asynchronous angle.Secondly,based on the identification of the positive sequence parameters and the unsynchronized angle,the positive sequence,negative sequence and zero sequence equivalent circuit diagrams of the single-phase ground fault are analyzed,and the fault distance is solved by the positive sequence and negative sequence networks.When the fault distance is known,the zero sequence parameter acts as the unknown quantity in an equation built using the zero sequence network,which is then solved using the L-M algorithm.Finally,using MATLAB software to build a single-return double-ended transmission line system,the proposed positive-sequence and zero-sequence parameter identification methods are simulated,and the effectiveness and accuracy of the proposed parameter identification methods are verified.