Stator Flux Oriented Sliding Mode Control of Sensorless Induction Motor Drives by Kalman Filter

This paper proposes to use a simple stator flux oriented-sliding mode control scheme in conjunction with a novel delayed-state Kalman filter based algorithm, estimating the stator flux linkage components, to realize sensorless induction motor drives. This control scheme has closed loops of torque and stator flux without Pi-type controllers and a minimum number of controller gains is required to obtain good performance without fine tuning. The delayed-state Kalman filter-based algorithm has the state-vector dimension 2times1. The measurement and model errors covariance matrices have dimension 2times2 and are diagonal. As a consequence the setting is not hard because only two parameters must be tuned. Moreover the proposed algorithm gives accurate estimates of stator flux linkage components in transient operations so that can be used in flux rising operations and in field weakening region. Experiments show that the new sensorless control is stable and effective at high and low speeds.