Improved utility harmonic impedance measurement based on robust independent component analysis and bootstrap check

In this study, a new method for utility harmonic impedance measurement based on robust independent component analysis (RICA) and bootstrap check is proposed. The RICA approach which adopts exact line search to seek the optimal step-size in iteration has better performance for short data records. At the same time, a bootstrap check technique to remove the singular solutions of this sort of independent component analyses methods is presented as well. This verification technique is performed through judging the dispersion degree of the estimates of the bootstrap samples which is quantified by the coefficient of variation. Based on the results of computer simulation and filed test, it is proved that the combination of the RICA approach with the bootstrap check technique can reduce the adverse impact of the background harmonic fluctuation and the singular solutions on impedance estimation effectively, and satisfactory measurement results can be acquired.