Quality Improvement of Speed Estimation in Induction Motor Drive by Using Fuzzy-MRAS Observer with Experimental Investigation

Abstract

Our work is oriented to improve the quality of observation and estimating speed of rotation of the asynchronous machine. This study is designed to cope with problems related to parametric variation, non-measurability of flux, coupling between flux and torque, and observation of speed. The precise determination of these quantities, which we have concentrated in our work, has contributed to the improvement of the quality of control and observation of the asynchronous machine. Furthermore, the current study will be devoted to present an oriented rotor flow control of induction machine fitted with MRAS and FUZZY-MRAS sensor, a speed estimator based on the MRAS technique whose estimation mechanism is provided by fuzzy logic. The experimental results obtained will be demonstrated to show the feasibility and effectiveness of such an estimator through a comparison in order to illustrate the performance at low speed, load torque and reverse direction of rotation. Thus, with a simple comparison between observed and measured currents, we can get the necessary information to evaluate the error speed. Then, a regulator is applied to minimize the errors that are found. As a matter of fact, this regulator serves as an adaptation mechanism; it is noted that the FUZZY-MRAS observer is stable at high and low frequency and converge asymptotically at high frequency. It is also robust to an application of a load torque and also to the reverse direction of rotation.