Boosting the performance of field-oriented control by using a model predictive direct current strategy

This paper presents a model predictive current controller and its application to the inner current control loop of a field oriented controller. In a stationary reference frame, the proposed control scheme keeps the α and β currents within given hysteresis bounds while minimizing the switching frequency of the inverter. Based on an internal model of the drive, the controller predicts the drive's future behavior for each switching sequence, extrapolates the output trajectories and selects the inverter switch position (voltage vector) that minimizes the switching frequency and keeps the predicted current trajectories within the hysteresis bounds. The scheme is applicable to a large class of (three-phase) ac electrical machines driven by inverters and it is also effective under all operating conditions, including transients operation. Specifically, the very fast transient response time of the classic hysteresis control scheme is inherited.