Sensorless Model-Free Predictive Current Control with Variable Prediction Horizon by Estimated Position for PMSM

Compared to the model predictive control (MPC) strategy with a short prediction horizon, the current quality can be improved by the long prediction horizon and conservative switching states, but its prediction error is increased and the prediction accuracy is affected. To solve this problem, a model-free predictive current control (MF-PCC) with a variable prediction horizon is proposed in this paper, and applied to the sensorless speed control system of the permanent magnet synchronous motor (PMSM). The rotor position is estimated by the sliding mode observer with saturation function to reduce buffet, and the estimated result is used to judge the prediction horizon according to the current operating state to consider the prediction error and current quality at the same time. The effectiveness of the proposed method is demonstrated under different operation conditions.