On the modelling of harmonic currents of a residential network

Abstract

Modern residential area are utilizing more and more sophisticated electronic equipments that are powered through power electronics. The harmonic emission resulting from an aggregated effect of such devices are becoming a growing concern for the supply quality of voltage. Current harmonic emission of a residential network was studied and modeled. In the first approach of the methodology, an average harmonic profile of a typical household was established from weekday measurements of three similar households. Aggregate current harmonic magnitude of the entire network was modeled by Fourier series components. A mathematical model was proposed for approximating and estimating harmonic emission emanating from the aforementioned network. The models were tested for prediction across unseen data; findings validate the suitability of the network models as the maximum resultant mean squared error was found to be under 7.2 percent of the largest value. As for the individual household, the proposed models perform well up to a certain degree. The second part of the thesis constructed probabilistic models representing the distribution of magnitudes of harmonic currents for a group of households in a bottom-up manner. The distributions were then evaluated against distribution of a network with similar amount of households.