Thrust Ripple Reduction for Linear Induction Motor Sensorless Drives Based on Finite Control Set–Model Predictive Thrust Control
Abstract
This paper presents a finite control set–model predictive thrust control (FCS–MPTC) strategy to enable a linear induction motor (LIM) for linear metro drives to attain lower thrust and flux ripples than the direct thrust control–space vector modulation (DTC–SVM) strategy. Considering some environmental conditions and cost-effectiveness, a model reference adaptive system was used to estimate the LIM linear speed. For the design process of the proposed strategy and LIM modeling, the influence of the end-effect phenomenon was considered. Considering a single 3 Kw arc induction machine (which was built to imitate the real LIM’s drive performance), extensive simulations and experiments revealed that the proposed FCS–MPTC strategy could realize lower thrust ripples by 6% and flux ripples by 1% than the DTC–SVM strategy. Moreover, the speed error between the estimated and actual speeds was about 0.22% of the reference value, validating the speed estimation scheme.