A new graphic method for stability analysis of speed sensorless FOcontrolled induction motor drives working at low speed in regenerativemode

摘要

In this paper, a graphic method to analyze, on the torque versusspeed plane, the stability of a speed sensorless field oriented (FO)controlled induction motor drive is proposed. A decoupling control isused to generate the voltage commands from the current commands insteadof the traditional current regulators. The speed is estimated using aLuenberger speed observer, that has been simplified taking into accountthe decoupling control equations. Special attention is given to thestability of the drive operation at low speed, in regenerative mode.This makes the proposed method interesting when the sensorless drivecontrol has to be designed, for example, for electric vehiclesapplications. The proposed method has been simulated and the resultsobtained are shown in this paper