Estimating harmonic impact of individual loads using harmonic phasor data

Abstract

Summary Owing to increased capabilities of power quality monitors, synchronized harmonic phasor data are becoming more widely available. Taking advantage of the new data, this paper presents a new and effective method to solve the problem of how to estimate the harmonic impact of several individual loads on the harmonic voltages at a specific location of a power network. The method uses the independent fluctuation of the harmonic sources and is solved as a blind source separation problem. The proposed method has been verified through simulation verification where harmonic currents measured at actual substations are used as input so realistic load fluctuations are considered. Furthermore, lab experiments are conducted to validate the proposed method.

A Harmonic Impedance Estimation Method Based on the Cauchy Mixed Model

“…At present, the mainstream methods for estimating the utility harmonic impedance are noninvasive, which mainly include the linear regression method [8][9][10][11][12][13], fluctuation quantity (FQ) method [14,15], independent random vector (IRV) method [16], and independent component analysis (ICA) method [17][18][19][20][21][22]. e linear regression method uses linear regression to calculate Norton equivalent circuit equation coefficient and obtain the harmonic impedance.…”

“…Besides, filters or reactive compensation capacitors are usually installed on the customer side, which may cause the harmonic impedances of both sides to be approximately equivalent. As for, the independence hypothesis of the harmonic sources of both sides is much idealized, and many researchers have pointed out that the assumption may not meet the practice [4,5,17,20,22].…”

Evaluation of Harmonic Contributions for Multi Harmonic Sources System Based on Mixed Entropy Screening and an Improved Independent Component Analysis Method

“…The above limitations have led to research on the multipoint model. This model contains centralized [ 16 , 17 ] and decentralized [ 18 , 19 , 20 , 21 ] categories as shown in Figure 1 . Nonlinear customers in the centralized model are directly connected at the concerned bus (the PCC).…”

“…Thus, it has the same limitations as the least squares method. To ensure evaluation accuracy even when background harmonics fluctuate, Wang and co-workers [ 21 ] expanded the application of the complex independent component analysis method (CICA) from the single point model to the decentralized multipoint model. Compared with the former two methods, CICA has a superior ability to resist the impacts from the background harmonics.…”

“…When many suspicious harmonic sources are involved, the calculation burden may increase, and the evaluation accuracy is thus decreased. Furthermore, the CICA method and the evaluation referred to by Wang and co-workers [ 21 ] rely on measurements with a Global Positioning System (GPS)-synchronized function that can synchronize the measuring time [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. However, in engineering practice, it is not realistic to install GPS-based measurements at all related buses because it is uneconomical [ 6 ].…”