Practical improvement of a simple V-I flux estimator for sensorless FO controllers operating in the low speed region

The aim of this paper is to show how the performance of a simple V-I flux estimator for field oriented (FO) controlled drives can be improved, simply by improving the quality of the input signals (voltages and currents) and eliminating the offset from the resulting flux signal, without using sophisticated mathematical methods such as Luenberger observers, Kalman filters or others. The proposed method requires almost no increase of the computation time in digital implementation, thus a cheap processor can be used