Equivalent Weighting Factor-Based Model Predictive Torque Control of SMPMSM

The design of the weighting factor in model predictive torque control (MPTC) is a tricky and time-consuming problem. To obtain the optimal weighting factor without the tedious tuning process, a finite control set MPTC (FCS-MPTC) based on equivalent weighting factor is proposed for surface-mounted permanent magnet synchronous motor (SMPMSM) drive system. The torque-flux error plane is first established, and the Pareto error points are selected from those corresponding to each voltage vector. By analyzing the Pareto error points, the mapping relationship between the weighting factors and the voltage vectors that minimizes the cost function is established. Then, the entire weighting factor interval is divided into several equivalent weighting factor intervals, and arbitrary value in each equivalent weighting factor interval corresponds to the same voltage vector. Therefore, each equivalent weighting factor interval can be substituted for arbitrary value in that interval, the infinite weighting factors are simplified to several equivalent ones. Finally, an evaluation criterion is designed to select the optimal weighting factor. As a result, the tedious tuning process is avoided, and the optimal weighting factor is achieved under different operating conditions. The experimental results show that the proposed method has superior performance of torque and flux.