Direct Predictive Speed Control with a Sliding Manifold Term for PMSM Drives

This paper proposes a new direct predictive speed control (DPSC) method for permanent-magnet synchronous machines (PMSMs), which eliminates the cascaded loops structure that is usually used in the conventional controller. A novel sliding manifold term is added to the cost function to realize the speed/current tracking. The proposed cost function is simple and easy to implement. Therefore, in comparison with the other DPSC methods, the proposed method does not need long prediction horizons, dynamically adjustable weighting factors or large weighting factors for the control variables with large time constants. The performance of the proposed method has been experimentally investigated and compared with: 1) conventional DPSC scheme and 2) a predictive current control with an outer PI controller (PI-PCC). The results demonstrated enhancement in the dynamic performance in comparison with the PI-PCC method and improvement in the steady-state response in comparison with the conventional DPSC technique.