Predictive Direct Speed Control of PMSM without Weighting Factors

Predictive direct speed control (PDSC) of electric drives eliminates the cascade control structure and provides faster speed and current/torque response, but suffers from the selection of weighting factors (WFs). This paper proposes a PDSC strategy without WFs for permanent magnet synchronous motor (PMSM) drives. The proposed method evaluates each control objective separately and decides on the optimum voltage vector using normalized Euclidean distances in $n$-dimensional space generated by the objective functions. Simulation results show that it provides good control performance in different operating conditions with its inherent overcurrent protection feature while simplifying the design process. Finally, the proposed method overcomes the difficulty of WF selection in the traditional PDSC strategy with a slight additional computational load and also improves the overall control performance.