Speed sensorless stator flux-oriented control of induction machine in the field weakening region

摘要

In a conventional speed sensorless stator flux-oriented (SFO) induction machine drive system, the estimated speed is delayed in transients by the use of a low pass filter. This paper investigates the problem of a conventional speed sensorless SFO system due to the delay of the estimated speed in the field weakening region. In addition, this paper proposes a method to estimate exactly the speed by using a Kalman filter. The proposed method is verified by simulation and experiment with a 5-hp induction motor drive.