Análise e comparação de técnicas de controle para aumento da eficiência energética de motores de indução trifásicos

Abstract

This research presents an analysis and comparison of control techniques that aim at increasing energy efficiency on driving three-phase induction motors. First, electrical and mechanical modeling of the induction machine are performed. To determine the control method was made a research on the methods proposed in the literature. After the analysis of the control methods, is defined indirect field-oriented control (IFOC) to be used in this project, consisting of four proportional and integral controllers (PI): rotor speed controller, rotor flux controller and stator currents in arbitrary reference controllers. For the study of increasing energy efficiency on induction motors driving, initially, losses in these engines are investigated. Considering IFOC control, a way to minimize the machine losses, is optimizing the rotor flux reference. It is raised a study on control techniques to obtain the flux optimization, which are divided into two main groups: by search control (SC) and loss-model-based control (LMC). Two methods are chosen, one for each category, to be analyzed and compared. The performance evaluation of the chosen techniques is performed, at first, through computer simulation results using the mathematical software MATLAB®, which were imposed several driving conditions. To support the analysis, drives are conducted on a physical platform, provided by PPGEE, where tests were carried out with different load conditions for each flux optimization technique studied. The results showed the real possibility of the use of these techniques to improve the energy use, in a vector drive of an induction motor. Among both techniques studied, the one that stood out, in order to improve energy efficiency, in all conditions imposed was LMC, both on the results obtained by simulation and those obtained through practical implementation.