An adaptive speed estimator for induction motors based on a Kalman filter with low sample time

In order to estimate the rotor flux and speed in an induction motor, the extended Kalman filter must be used rather than the linear one. The main drawback of the extended Kalman filter is the great number of arithmetic operations required. This paper presents a linear Kalman filter for rotor flux with adaptive speed estimation that reduces the number of operations by a factor of 8.5 compared with the straightforward implementation of the extended Kalman filter.