Sensorless adaptive speed control for PMSM drives

The simplified mathematical model of the permanent magnet synchronous motor is developed in this paper. Speed and torque controls of permanent magnet synchronous motors are usually attained by the application of position and speed sensors yet, speed and position sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of the motor. Therefore, many studies have been performed for the elimination of speed and position sensors. Therefore, a V-I model based model reference adaptive control is proposed. A Model Reference Adaptive Control (MRAC) has been formed using parameter uncertainty cancellation to estimate the speed without using any sensor. Firstly, the speed estimation errors of a voltage and current model-based adaptive speed due to the parameter variation are analyzed. Consequently, an adaptation mechanism model is developed to cancel the effects of parameter variations on the estimated speed performance. Finally, the speed control with quantitative control performance considering the effect due to the feedback of estimated speed is presented. The results show that the MRAC is superior to the conventional PI controller in dynamic performance and steady precision. The effectiveness of the proposed controller is demonstrated by some simulation by using MATLAB/SIMULINK.