A new integration algorithm for stator flux estimation in sensorless AC motor drives

This paper presents a new integration algorithm for stator flux estimation based on voltage model. This algorithm is composed of a second-order band pass filter (BPF) and a component which can effectively compensate magnitude and phase angle errors between the BPF and ideal pure integrator. The effect of the poles location of the BPF is studied, and the poles are located adaptively according to the operation frequency. The performance of the algorithm is evaluated by simulation and experiment. The results show that this algorithm is very effective to solve the problems associated with the integration of the back electromotive force (Back EMF), and can be used in high-performance sensorless ac motor drives over a wide speed range.