Avaliação do compartilhamento de responsabilidade harmônica considerando incerteza nos equivalentes de impedância

Abstract

This dissertation presents a new methodology to calculate, in percentage, a responsibility attribution index for harmonic distortions at the Point of Common Coupling (PCC) between the utility company and the consumer. In this work, an optimization problem is proposed, considering as state variables the currents and impedances of a Norton equivalent representing the system from the PCC between the consumer and the supplier. The objective function is formulated using the least squares method, where the goal is to minimize the difference between the measured voltage/current values and the respective values calculated through the state variables. For determining the objective function, it is assumed that voltage and current measurements at the PCC are obtained by a phasor measurement unit. The results demonstrate that the methodology is capable of calculating the indices even when there is uncertainty in the impedance values. In the proposed methodology, it is necessary to ensure that the real values are within an acceptable range. This problem is addressed by establishing lower and upper limits associated with the optimization problem. The methodology is tested in three systems: an equivalent distribution system, represented by the Norton equivalent on the consumer side and the utility side, coupled at the PCC; the IEEE Benchmark system for responsibility attribution; and a radial 5-bus tutorial system. The main contribution of this research work is the proposal of a new optimization model that allows evaluating the sharing of harmonic responsibility in a deterministic way, considering uncertainties associated with the equivalent impedance values on the consumer and energy supplier sides. The results obtained by the proposed methodology are validated through computational tests on test systems, demonstrating the applicability of the method in scenarios closer to the operation of electric power systems.