Controle vetorial em quadratura de velocidade em motores de indução trifásicos para aplicações em controle de vazão de ar em ventiladores industriais

Abstract

Air flow control through of fans can be applied in various areas, from industry, in combustion or air renewal processes, to commercial and residential air conditioning systems. The fans responsible for airflow control are equipment whose driving force is provided by the coupling of electric induction motors on their blades, and the flow control is directly related to the motor speed control, according to the first law of fans. There are some ways to control the speed of induction motors: change in the number of poles, variation of the supply frequency, or with vector control techniques, which have good dynamic performance and efficiency. The so called vectorial techniques provide a decoupling between the magnetic flux and conjugate, enabling the independent control of these quantities, but requiring a well established dynamic model of the motor, so that it is possible to perform the tuning of the control loops. Based on this, and considering the importance of a reliable flow control, this paper aims to design a quadrature vector control system with the stator flux in closed loop, by obtaining a dynamic model of an induction motor applied to a load that simulates a fan, from an analytical methodology for obtaining the parameters of the motor model. The tests and simulations, as well as the controllers tuning were developed with PSIM and MatLab software, where results were obtained that proved the validity of the model development methodology and the controllers tuning, as well as the speed control in permanent regime foreseen.