Avaliação dos impactos das variações sistêmicas nas análises de viabilidade do religamento monopolar através do ATP via Python

Abstract

This dissertation presents a new approach to evaluate the impacts of systemic variations on the success analysis of the monopolar auto reclosing performed in the basic design stage for transmission lines integrated into the national interconnected system. As shown in the statistics, approximately 80 % of short circuits in the power system are caused by phase-to-ground faults. In this context, whenever possible, it is recommended to adopt the practice of monopolar reclosing instead of tripolar reclosing, due to its systemic benefits such as reduced torsional stresses on machines, lower transient overvoltage during switching operations, and reduction in the intensity and duration of voltage sags, among others. The success of monopolar auto reclosing is closely related to the elimination of secondary arc currents induced by healthy phases and parallel-operating circuits. Therefore, in the design stage of new transmission lines, it is essential to seek alternatives that minimize the secondary arc current, which consequently increases the probability of successful reclosing. The evaluation of such alternatives is commonly performed using electromagnetic transient programs such as ATP, PSCAD, EMTP-RV, among others. In this dissertation, the transient solution of the system will be carried out using ATP. Although this software has features to compute multiple scenarios, managing and analyzing the impacts of various system variations on transient responses can become a challenging task prone to errors. Considering the above, the main objective of this work is to present a methodology that allows simulations in ATP through master algorithms implemented in Python, which can operate ATP files to perform specific simulations with predefined parameters. Thus, it becomes possible to analyze the behavior of secondary arc current and transient overvoltage induced in the system as a function of parameter variations such as the neutral reactor value, line length, compensation level, typical line silhouette topology, etc. For the case studies, typical structures were considered for voltage levels of 230 and 500 kV. For the latter, both conventional and high surge impedance loading lines were modeled, which have become increasingly common in planning solutions for carrying large amounts of generation to load centers. As results, the work graphically presents the behavior of monitored quantities in the monopolar auto reclosing analysis as a function of the changes for each studied line. These graphs allow for sensitivity analysis and can assist in the design and definition of solutions that seek to enable monopolar reclosing.