Sliding-mode direct torque control and sliding-mode observer with a magnetizing reactance estimator for the field-weakening of the induction motor drive

The paper deals with the sliding-mode control and the sliding-mode speed observer for the induction motor drive. The main interest of the paper is high speed operation, during the field-weakening, where the machine magnetizing characteristic is of great importance. Therefore the magnetizing reactance estimator, based on the magnetizing curve identification is used. The sliding mode technique is applied to design the direct control of the induction motor torque. A unified designing approach for control as well for the state space variables estimation is shown. Simulation and experimental results are shown to illustrate described problems.