Desenvolvimento de uma planilha eletrônica automatizada para auxílio na elaboração de projetos de redes de distribuição trifásicas em baixa tensão

Abstract

The development of three-phase low-voltage (LV) distribution network projects is a complexengineering activity, marked by the need for high-precision calculations (demand, ampacity,and voltage drop) and adherence to rigorous technical standards, such as those from ABNT andenergy utility regulations. The traditional, manually executed process consumes significant timeand is highly susceptible to errors, limiting designers’ ability to optimize and analyze alternatives.In response to this challenge, this work describes the development of an automated electronicspreadsheet prototype, designed to assist and integrate the dimensioning of these networks. Thetool was modeled using a coordinated architecture of spreadsheets and custom functions inVBA (Visual Basic for Applications), including an adaptable normative database. This structureallowed for the complete automation of critical processes, from the selection of demand methods(measurement, density, and estimation) and topology calculation (geographic and average spans),to the decision-making regarding transformer selection and the automatic verification of voltagedrop and ampacity limits for every circuit span. Using the technical parameters of the utilitycompany Enel Distribuição Ceará as a case study, comparative tests were performed acrossthree distinct scenarios. The results confirmed the tool’s absolute precision, replicating manualcalculations with fidelity across all dimensioning logics. The efficiency gain was quantifiedas an average time reduction of 80.1% in project completion, establishing itself as a resourcethat not only designs but also allows for the rapid correction and re-elaboration of projects inresponse to parameter changes or optimizations. It is concluded that the prototype is a highlyeffective resource, ensuring normative compliance and freeing the designer to dedicate moretime to critical and strategic analysis than to executing repetitive tasks.