Estimação dos parâmetros elétricos de motores de indução em condições de operações de malha aberta e malha fechada.

Abstract

The purpose of this thesis is to present three methods for estimating all parameters of induction motors operating in open-loop (method I) or in closed-loop (method II and method III). The parameters are obtained by solving a recursive least squares minimization problem. In each method, the estimation procedure is split in three parts. First, the stator leakage inductance and the stator resistance are determined by using the homopolar machine model. Second, given the previously estimated homopolar parameters and using the dynamic dq model, all the other parameters are determined. In method I, the dq model estimation is derived for open-loop operation. In method II and III, the dq model estimation is derived for the case where the stator currents of the motor are regulated via a linear feedback controller. Finally, the complete set of electrical parameters is determined. Moreover, the estimation methods in closed-loop are used to control online the flux and electromagnetic torque of an induction motor. Selected experimental and simulation results are used to demonstrate the feasibility and performance of the proposed methods.