State and Resistance Estimation in Sensorless FOC Induction Motor Drive Using a Reduced Order Unscented Kalman Filter

In this paper, an unscented Kalman filter is proposed for state and parameter estimation on a speed sensor less field-oriented control of an induction motor. The stator resistance is estimated as part of the state to improve the robutness of the flux estimate, at the expense of leading to a highly nonlinear model. Additionally to reduce the computational load the filter is implemented as a reduced order observer, estimating only the non-measured state variables.