Low-Complexity Finite Control Set Model Predictive Control With Current Limit for Linear Induction Machines

In order to limit the armature current within a safe region, this paper proposes a finite control set model predictive control (FCS-MPC) method for linear induction machines (LIMs) by adding a penalty overcurrent term in the cost function. The modulation strategies based on two and three voltage vectors are combined with FCS-MPC so as to reduce the current ripples and steady-state tracking errors. Three different search methods have been developed to help reduce the computational burden by excluding many unsuitable participating voltage vectors and combinations in advance. These search methods are also effective for FCS-MPC with current limit. Finally, some key performance indexes are fully compared for LIMs controlled by different FCS-MPC-based modulation strategies through comprehensive numerical simulation and experiments on a test bench with two 3-kW arc induction motors. It is shown that the proposed low-complexity control strategies can effectively avoid overcurrent under any circumstances.