Proposta de comutação com chaves eletrônicas da capacitância dinâmica para controle de motores de indução trifásicos assimétricos

Abstract

Currently in Brazil, a large portion of the population still live in rural areas, an area which plays a vital role in fortifying the economy. The single-phase power grid, using one or two conductors, represents an extremely viable alternative for the Brazilian energy sector, especially in the delivering of rural loads, certainly due to the low investment associated, chiefly when compared to the three-phase power distribution grid. Considering this scenario, the present work aims at collaborating with the expansion of the electric energy market in rural areas, by offering an innovative solution to problems through the asymmetric three-phase induction motor powered by a single-phase voltage source. In this system, when capacitor switching is applied throughout its operation, i.e., even with motor load variation, the switching system manages to maintain the motor efficiency when compared to the original three-phase motor. Theoretical results are presented for the application of this switching on an asymmetric three-phase induction motor of 2 hp. This analysis allows satisfactory conclusions in terms of the operation of the asymmetric three-phase induction motor equipped with a capacitor switching system. The work shows that the proposal is constructively simple, while offering low maintenance requirements and pointing to extremely attractive investments