Abstract
This paper presents the sensorless speed control performance of an improved direct torque and flux control (DTFC) for induction motor. The proposed DTFC is based on fuzzy logic technique to replace switching table and hysteresis regulator, in order to reduce torque and flux ripples in comparison with the conventional DTFC. We estimated the rotor speed by using the Model Reference Adaptive Systems (MRAS). Several strategies of speed control are presented and tested: Proportional Integral regulator (PI) anti-windup, PI with and without saturation and PI fuzzy logic. The validity of proposed technique is verified by simulation results using Matlab/Simulink. In this article recent patented strategies are also discussed.
Keywords: Induction motor, DTFC, MRAS, sensorless control, fuzzy logic
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