Utility side Harmonic Impedance Estimation Method Based on Distance Correlation Coefficient

The accurate estimation of harmonic impedance is a prerequisite for harmonic management and a reasonable division of harmonic responsibility. Existing harmonic impedance estimation methods require that the background harmonic fluctuations are small and that the harmonic currents on the customer side and the utility side are independent of each other. However, the lots of new energy sources connected to the grid, these conditions may not always hold in modern power gird. Therefore, this paper proposes a method for estimating harmonic impedance based on a filtering method of distance correlation coefficients. The proposed method screening out independent data sets of customer-side harmonic currents and utility-side harmonic currents, both sides harmonic currents can be estimated by complex independent component analysis (ICA). Compared with the existing methods, the proposed method is more accurate in estimating impedance and is more widely applicable. The validity of the method is tested through simulation experiments and analysis of measured data.