A Novel Method for Noninvasive Estimation of Utility Harmonic Impedance Based on Complex Independent Component Analysis

Abstract

This paper presents a new noninvasive method for calculating utility harmonic impedance at the point of common coupling (PCC). The proposed method is based on a statistical signal processing technique, known as independent component analysis (ICA). The complex ICA technique is applied to the equations derived from Northon equivalent circuit model at the PCC in order to estimate the utility harmonic current values. Then, the estimated values of the utility harmonic current are used in an optimization problem to calculate the utility harmonic impedance. Due to considering the utility harmonic current variations in utility harmonic impedance calculation, the proposed method is relatively robust against the background harmonic fluctuations. The results obtained from computer simulation and real case study verify the effectiveness of the proposed method.Index Terms-Harmonic impedance, power quality (PQ), noninvasive method, background harmonic. 0885-8977 (c)

Estimating harmonic impact of individual loads using harmonic phasor data

“…(2) The first and second conditions require the source signals to be statistically independent and non‐Gaussian distribution. To meet this condition, a moving average filter should be applied to the data to remove the slow trend component and remain the random fluctuation component of the harmonic load . The slow trend components of different harmonic loads could be similar.…”

“…To meet this condition, a moving average filter should be applied to the data to remove the slow trend component and remain the random fluctuation component of the harmonic load. 9 The slow trend components of different harmonic loads could be similar. For example, many harmonic loads experience heavy load in daytime and light load in nighttime.…”

“…Many solutions have been suggested in the literature. For example, one group of single‐point methods determines the harmonic impact based on the information of system harmonic impedances . There are also some other advanced single‐point methods without using any information of the system side, such as the nonactive power–based method or the artificial neural network–based method .…”

“…For example, one group of single-point methods determines the harmonic impact based on the information of system harmonic impedances. [4][5][6][7][8][9] There are also some other advanced single-point methods without using any information of the system side, such as the nonactive power-based method 10 or the artificial neural network-based method. 11 While the single-point problem is still an active research topic, another type of problems called the multipoint problem has emerged, owing to primarily the situations where List of symbols and abbreviations: V hX , the hth harmonic voltage at bus X; V hXA , the hth harmonic voltage at bus X caused by the load A; V hXA_P , the projection of V hXA on V hX ; V h0 , the hth background harmonic voltage at bus X; V hA , the hth harmonic voltage measured at the PCC of load A; I hA , the hth harmonic current measured at the PCC of load A; I hAU , the hth system harmonic current seen at the PCC of load A; I hAL , the hth harmonic current of load A; Z hAU , the hth system harmonic impedance seen at the PCC of load A; Z hAL , the hth load harmonic impedance seen at the PCC of load A; Z hXA , the transfer harmonic impedance (hth) between load A and bus X; Z hTA , the transfer harmonic impedance (hth) between load A and bus X without load A's load impedance in the system; HI Bus X Load A , the harmonic impact of load A on bus X there are more and more loads containing harmonic sources.…”

MatLab Simulink Modeling for Network-Harmonic Impedance Assessment: Useful Tool to Estimate Harmonics Amplification

“…There are many methods for network harmonic impedance determination, which are presented in many literature works [6][7][8][9][10][11][12]. Even the operation of switching the capacitor bank can be used for harmonic impedance measuring [13], and online determination of the harmonic impedance is the subject of many works [14,15].…”