A fuzzy-based approach for harmonic contribution determination at points of common coupling

The main objective of this paper is to present an approach based on Fuzzy Inference Systems for the determination of harmonic contribution at Points of Common Coupling (PCC), i.e., it is intended to determine the harmonic distortion responsibilities between consumer and utility at these points. For this purpose, the proposed approach uses some features extracted from the voltages and currents measured at PCC and in a branch where a capacitor bank was allocated (between the PCC and the ground). So, the measurements were acquired in two different stages (before and after the switching of the capacitor bank). Among these features, RMS voltages, crest factor and Telephone Interference Factors (TIF) can be highlighted. Thus, some case studies were modeled and simulated by using the Alternative Transients Program (ATP) in order to obtain the voltage and current signals. In this sense, two Fuzzy Inference Systems were employed and each one is responsible for identifying the contribution of utility and consumer. However, an ensemble of Fuzzy Inference Systems was created, more specifically, 8 systems to estimate the individual contributions for the 3^rd, 5^th, 7^th and 9^th harmonic orders. Finally, the proposed approach has its results evaluated, which were considered satisfactory for this problem, due to the lower calculated error between the estimated and simulated values.