Controle Direto De Torque (DTC) com Estimação de Conjugado

Abstract

The three-phase induction motors are widely used in industry once they can work in adverse environmental conditions due mainly to the inexistence of brushes. The speed control of these machines by electronic converters has been increasing in the last years, reducing the drives of loads by Machines of Continuous Current. However, in high-performance drives, speed control requires sophisticated control techniques. A technique adopted in industrial frequency converters is the Direct Torque Control (DTC) that aims to control torque and flux directly, instead of trying to control these variables indirectly. The use of a torquemeter to measure the torque, is onerous and decreases the robustness of the drive and also increases maintenance costs. Thus, the objective of this work is to propose a method of estimation of electromagnetic torque to be applied in the control loop to replace the torquemeter. Computational studies for motors of different characteristics and conditions of load operation were performed and show the robustness of the proposed method. The technique has strong industrial appeal because it requires only the signals of sensors present in the control loop.