Controle de velocidade e estimação de fluxo rotórico por observador do motor de indução.

Abstract

Microprocessor-based high-performance vector control systems are widely used in industrial applications. The success of vector control schemes depends on knowledge of the position and magnitude of the rotor flow vector. This work presents the modeling, control of the induction motor by direct field with rotor flux estimation by observer. From the idealized continuous model of the induction motor in the form of state variables, a discrete model is derived and analyzed. With the aid of the decoupled control conditions the oriented field strategy is mentioned. Flow, current and velocity regulators are designed and simulation results from the direct oriented field strategy are presented using the actual flow. The reduced observer theory is presented and the reduced-order rotor flux observer for the induction motor is derived. The gain matrix of the observer and the positioning of the poles as a function of the motor speed are proposed. The flicker observer is discretized. Then, to take into account the computational delay, the flow and current regulators are discretized. The transfer functions of the system are obtained using the modified Z transform. The Jury criterion and the polar diagrams are used to select the parameters of the flow and current controllers. The discrete simulation of the complete drive system is displayed. Considering the observer's parametric dependence, an observer / identifier based on the Luenberger's extended observer is formulated for rotor flux estimation combined with the identification of the rotor time constant. The observer / identifier computation results are given.