A Comparative Study Between Tree Philosophies of Stator Flux Estimation for Induction Motor Drive

This paper shows and compares three different flux estimator algorithms developed for use in high- performance sensorless ac motor drives. The first algorithm uses a low pass filter with a very low cut off frequency to integrate the back electromotive force (emf). The second one uses a high pass filter to remove the offset present in the signal before it´s integration. The third algorithm uses current and voltage model to estimate the flux of induction motor. These algorithms can be used to accurately measure the motor flux including magnitude and phase angle over a wide speed range. The performance of the algorithms is investigated, compared, and verified using simulation. Preliminary experimental results are also included.