A low memory disturbance elimination method for sensorless control of induction motor drive using test vector injection

This paper presents an enhanced method for both speed and rotor position estimation in induction motor drives. A modified INFORM method is used to excite magnetic saliencies in the motor created by saturation and rotor slotting, from which position signals can be derived. A new method is proposed for the elimination of second order saturation effects from position signals. This method significantly improves the quality of the rotor position estimate such that it can be used for indirect rotor flux vector control of 30 kW induction machine, but does not require extensive look-up tables stored within the controller. This "low memory" approach is suitable for both star and delta connected machines. Experimental results for the shaft sensorless control showing the tracking of rotor speed and position are presented