Experimental tuning and design guidelines of a dynamically reconfigured weighting factor for the predictive torque control of an induction motor

In this study, an experimental approach for the weighting factor design of the predictive torque control of an induction motor (IM) is presented. The weighting factor is set to the value which yields a low total harmonic distortion (THD) figure in the phase currents. Then, this optimized value is dynamically adjusted with respect to the speed error term, which is defined as the magnitude of difference between the commanded speed and the actual speed. By doing so, superior transient performance is achieved without sacrificing steady-state THD values. The presented approach for dynamically adjusted weighting factor is tested on a two-pole, 500 W IM, driven by a two-level voltage source inverter (2L-VSI), via finite control set model predictive control (FCS-MPC). Experimental results show the effectiveness of the proposed method: by the adoption of dynamic lambda approach, speed reversal time from -3000 rpm to +3000 rpm is decreased by 38% under the same controller structure and settings.