Controle de velocidade sensorless para motores de indução trifásicos

Abstract

This paper presents an analysis and implementation of vector control strategies without the use of speed sensors for three phase induction motors. The aim is to study the performance of a control technique against parameter variations in variable speed drives. The determination of the control technique is realized firstly through a bibliographic review for the techniques of speed estimation. The three-phase induction motor is driven using the technique of indirect field-oriented control (IFOC), consisted of four proportional-integral controllers (PI) flux controller, speed controller and direct axis and quadrature axis current controllers. For the sensorless speed control design, it was used the technique of an adaptive system based on a reference model (MRAS). The simulation results are showed using the Matlab® simulation environment and the experimental results using an electric machinery platform and the DSP TMS320F28069. From these results, both the simulation and the experimental results were compared. With that accomplished the comparison of simulation results with experimental, in which the estimation of speed showed less than 5% error with respect to speed as measured by the sensor connected to the shaft. This percentage deviation occurs in 5% worse considering the load disturbance and at low speeds. However, with an increase in the reference speed near the nominal, deviation between the estimated and obtained by the speed sensor decreases to 1,22%.