基于快速独立分量分析的系统侧谐波阻抗计算方法

提出一种基于快速独立分量分析(FastICA)计算系统侧谐波阻抗的方法。根据系统侧和用户侧谐波源变化近似独立,用FastICA对公共耦合点电压与电流波动的x-y正交分量解混得到独立分量,利用最小二乘法求得混合系数;根据混合系数之间的线性关系,计算系统侧谐波阻抗值。该方法考虑系统侧和用户侧谐波的共同影响,一定程度上削弱了系统侧谐波变化的干扰,在谐波源相角波动较大情况下,具有更高的计算精度,且无需先验数据匹配。仿真分析和现场数据计算结果表明,该方法可以有效抑制系统背景谐波干扰,得到更为准确的系统侧谐波阻抗值。

Method of Calculating System-side Harmonic Impedance Based on FastICA

This paper reports a method to calculate the system-side harmonic impedance based on fast independent component analysis (FastICA). Since harmonic emission of the system-side is approximately independent of the customer-side, x-y orthogonal components of voltage and current fluctuations at the point of common coupling can be demixed by FastICA to obtain independent components, and the mixed coefficients can be calculated by using ordinary least square. Thus the system-side harmonic impedance is figured out according to the linearity of mixed coefficients. By considering the joint influence of both sides, this method can reduce the system-side interference to a certain extent. The proposed method provides more accurate results in the case of larger phase-angle fluctuations without prior data to match. Based on an analysis of simulation results and field test, it is proved that the above method is effective in suppressing system harmonic interference and able to yield more accurate harmonic impedance.