METHODOLOGY FOR THE ECONOMIC SIZING OF LOW-VOLTAGE ELECTRICAL CONDUCTORS: AN INTEGRATED APPROACH TO COSTS, POWER FLOW, AND CO₂ EMISSIONS

Abstract

This study presents a methodology for the economic sizing and techno-economic analysis of low-voltage feeder cables, integrating cost, power flow, and CO₂ emission assessments to support more efficient and sustainable conductor section selection. The proposed approach was validated through a case study analyzing the QGBT2 feeder circuit (46 kVA/220 V) installed at the School of Technology of the Amazonas State University (EST/UEA). The results indicated an economic cross-section of 226 mm², leading to the evaluation of two standardized options: 185 mm² and 240 mm². The 240 mm² cable achieved the lowest total cost (R$ 237,176.56) and an operational cost 60% lower than the 95 mm² cable currently in service, while dissipating 2.61 times less energy. Voltage drop was reduced from 2.5% to 0.97%. The economic feasibility analysis showed a payback period of 13 years and a net present value of R$ 12,995.80. The findings highlight the importance of technical and economic sizing in accordance with NBR 5410:2004 and NBR 15920:2011 standards, complemented by additional studies aimed at improving decision-making efficiency.