Control of induction machine based on mathematical model with included anisotropy

The paper concerns with improving the field-oriented controlled induction machine torque and speed accuracy and performance from a control theory viewpoint. A simple model is derived that includes first harmonics of real machine phenomena such as inherent asymmetries, saliencies and anisotropy. We design adaptive proportional-integral controllers based on that model to achieve best possible torque performance. The control algorithm is conceived as an extension of conventional induction machine rotor field-oriented control. The usual Kalman filter approach for state estimation required by field-oriented control is extended to identify the contribution and location of asymmetries in a dual filter approach with unscented Kalman filter. Simulation results are obtained for a 5.5 kW machine with modeled stator and rotor anisotropy. Undesired effects like torque and speed pulsations are greatly reduced with the proposed controller.