基于联合对角化数据分离与筛选的谐波阻抗计算

Harmonic impedance calculation based on JADE data separation and screening

系统谐波阻抗的精确估计对谐波责任划分和谐波溯源有重要意义。提出用联合对角化法(JADE)对公共点(PCC)处谐波电压和电流波动量值进行分离,求得混合矩阵,再通过其中的线性关系计算系统谐波阻抗值。针对数据测量和采集误差,提出用拉伊达准则进行数据清洗,考虑到电力系统稳定运行时系统谐波阻抗不会突变以及其实部为正的特性,在求得系统谐波阻抗值后,提出阻抗值不突变与符号判别的数据筛选准则。对所提方法进行了仿真和实际案例计算,计算结果表明:与传统方法相比,文中方法能够有效提高计算精度。

Accurate estimation of system harmonic impedance is of great significance for harmonic responsibility division and harmonic traceability.It is proposed to use the joint approximate diagonalization of eigen-matrices(JADE)to separate the harmonic voltage and current fluctuation values at the common point(PCC)to obtain the mixing matrix,and then,the system harmonic impedance is calculated through the linear relationship.Aiming at data measurement and acquisition errors,data is cleaned by Pauta criteria.Considering that the harmonic impedance of the system will not be abrupt and the real part is positive when the power system is running stably,the data screening criterion of impedance value non-mutation and symbol discrimination is proposed after the system harmonic impedance is obtained.The simulation and field case calculation of the proposed method are carried out.The calculation results show that compared with the traditional method,the proposed method can effectively improve the calculation accuracy.