Uma proposta metodológica para a atribuição da responsabilidade das VTCDs baseada na correlação dos fatores de desequilíbrio

Abstract

Short Duration Voltage Variations (VTCDs) are phenomena that, although occurring during a short period of time, can result in significant impacts on transmission/distribution networks or consumers. Notwithstanding the fact that this subject is contemplated in national legislation through the so-called Impact Factors (IF) that quantify the occurrences, there is, however, no mention of the issue of responsibility for the event. Aiming to offer ways to identify the origin of the phenomena, this master's dissertation is focused on the proposition of a strategy aimed at attributing responsibility for the herein considered phenomenon. The method is based on the use of indicators related to the factors of voltage and current imbalances, and their transference processes, through the arrangements used for the connections of the transformers primary and secondary windings. The proposal is presented as an alternative to the propositions found in the literature, which, so far, do not show consolidated analysis processes for use in the field. To meet the purposes of the research, the work begins with a theoretical grounds, based on the classical theory of electrical systems, from which the principles governing the correlation between the imbalance factors determined for both sides of the transformers that establish the connections between two agents involved in the study, namely, an upstream and a downstream network of the systems interconnection unit. Once the methodological principle has been established, mathematical and computational studies are carried out involving modelling techniques in the frequency and time domain. Through analysis of the performance results obtained, an evaluation of the consistency of the process, its feasibility for use in the field and perspectives regarding the fulfilment of the established purposes is carried out.