TY - JOUR
T1 - Sensorless field orientation of an induction motor drive using a time-varying observer
AU - Korlinchak, C.
AU - Comanescu, M.
PY - 2012/7
Y1 - 2012/7
N2 - The study discusses the problem of state and rotor flux position estimation for the induction motor (IM) drive and presents a sensorless time-varying observer. The method treats the induction motor as a time-varying plant and uses non-linear techniques to develop a state observer based on the motor's model in the stationary reference frame. Initially, the observer is developed assuming that the speed of the motor is available through measurement - the resulting observer is asymptotically stable and some of its gains are time varying. To obtain a sensorless observer, the speed measurement is eliminated by replacing the speed signal with a speed estimate (assumed to be inaccurate but reasonably close to the real speed). The observer with improper speed is analysed - this is not asymptotically stable; however, the estimated fluxes are in phase with the real fluxes. This property allows estimation of the rotor flux angle of the IM. This is because the accuracy of the direct field orientation method that is based on the tan-1 function only depends on the phase of the flux components. The study shows that the observer yields fluxes with magnitude higher than real when the speed signal fed in the observer is smaller than real (and vice versa). The design of the observer under improper speed is analysed theoretically; it is then supported by simulations and is validated by experimental tests.
AB - The study discusses the problem of state and rotor flux position estimation for the induction motor (IM) drive and presents a sensorless time-varying observer. The method treats the induction motor as a time-varying plant and uses non-linear techniques to develop a state observer based on the motor's model in the stationary reference frame. Initially, the observer is developed assuming that the speed of the motor is available through measurement - the resulting observer is asymptotically stable and some of its gains are time varying. To obtain a sensorless observer, the speed measurement is eliminated by replacing the speed signal with a speed estimate (assumed to be inaccurate but reasonably close to the real speed). The observer with improper speed is analysed - this is not asymptotically stable; however, the estimated fluxes are in phase with the real fluxes. This property allows estimation of the rotor flux angle of the IM. This is because the accuracy of the direct field orientation method that is based on the tan-1 function only depends on the phase of the flux components. The study shows that the observer yields fluxes with magnitude higher than real when the speed signal fed in the observer is smaller than real (and vice versa). The design of the observer under improper speed is analysed theoretically; it is then supported by simulations and is validated by experimental tests.
UR - http://www.scopus.com/inward/record.url?scp=84863770617&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863770617&partnerID=8YFLogxK
U2 - 10.1049/iet-epa.2011.0245
DO - 10.1049/iet-epa.2011.0245
M3 - Article
AN - SCOPUS:84863770617
SN - 1751-8660
VL - 6
SP - 353
EP - 361
JO - IET Electric Power Applications
JF - IET Electric Power Applications
IS - 6
ER -