Predictive current controller for sensorless induction motor drive

A new speed sensorless control system for an induction motor with predictive current controller is presented. An adaptive observer system with high robustness against parameters variation is used for the control approach. The new observer computes a back EMF correctly even at zero speed and zero frequency. The current predictive controller is improved by utilizing the new observer system for different operating points. The proposed idea makes the system insensitive to the changes of motor parameters even at zero frequency. It is proved that the drive system is applicable to high dynamic performance and wide range of rotor speed. Simulation and experimental results are shown.