A Rotor Flux Estimation During Zero and Active Vector Periods Using Current Error Space Vector From a Hysteresis Controller for a Sensorless Vector Control of IM Drive

• Published in: IEEE transactions on industrial electronics (1982) 2011-06, Vol.58 (6), p.2334-2344
• Main Authors: Patel, Chintan, Ramchand, Rijil, Sivakumar, K, Das, Anandarup, Gopakumar, K
• Format: Article
• Language: English
• Subjects: Current error space phasor hysteresis controller; Electric potential; Error correction; Error detection; flux position estimation; Hysteresis; induction motor drive; Induction motor drives; Inverters; Low voltage; Machine vector control; Magnetic hysteresis; Mathematical analysis; Motors; Rotors; Sensorless control; sensorless vector control; Stators; Vectors (mathematics); Voltage; Voltage control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2010.2058077

This paper proposes a sensorless vector control scheme for general-purpose induction motor drives using the current error space phasor-based hysteresis controller. In this paper, a new technique for sensorless operation is developed to estimate rotor voltage and hence rotor flux position using the stator current error during zero-voltage space vectors. It gives a comparable performance with the vector control drive using sensors especially at a very low speed of operation (less than 1 Hz). Since no voltage sensing is made, the dead-time effect and loss of accuracy in voltage sensing at low speed are avoided here, with the inherent advantages of the current error space phasor-based hysteresis controller. However, appropriate device on-state drops are compensated to achieve a steady-state operation up to less than 1 Hz. Moreover, using a parabolic boundary for current error, the switching frequency of the inverter can be maintained constant for the entire operating speed range. Simple σL s estimation is proposed, and the parameter sensitivity of the control scheme to changes in stator resistance, R s is also investigated in this paper. Extensive experimental results are shown at speeds less than 1 Hz to verify the proposed concept. The same control scheme is further extended from less than 1 Hz to rated 50 Hz six-step operation of the inverter. Here, the magnetic saturation is ignored in the control scheme.