Proposta metodológica para determinação do fator de potência sob condições distorcidas e desequilibradas

Abstract

This work has as main focus the analysis of the influence that the harmonic distortions and the imbalances exert in the errors of measurement of electric energy in three-phase billing meters of active and reactive power. Such equipment is typically designed to be installed in fully balanced and symmetrical power plants, a fact that does not reflect the current conditions of the distribution network. Initially, the most relevant power calculation methodologies of the literature were raised, and their equations were implemented in a computational environment (MATLAB), in order to obtain comparative indicators between them. After obtaining the comparative results, a standard laboratory structure was set up for tests of energy meters, where they were submitted to a battery of tests with different levels of harmonic distortions and imbalances, according to the proposed test book. Once the tests were carried out, there was a great inconsistency between the results obtained by each meter, so it is necessary to recommend an alternative calculation methodology capable of standardizing the measurements in a way that does not harm the parties involved, whether the electricity utility or the final consumer. Based on the recommendation made, it was implemented in a prototype meter, along with the other methodologies, for comparative purposes. Finally, a measurement campaign was carried out in different plants, with the prototype, where the results obtained for active power measurement showed low deviations in relation to the accuracy class of the meters. However, when considering the reactive energy, the different methodologies showed deviations of more than 20 percent in some plants.