Title: Synchronous reference frame sliding mode observers for the inverse of the rotor time constant of the induction motor

Authors: Mihai Comanescu

Addresses: Penn State Altoona, 3000 Ivyside Park, Altoona, PA, USA

Abstract: The paper discusses the problem of inverse rotor time constant estimation for the induction motor (IM) and presents two sensorless sliding-mode observers (SMOs) that are constructed using synchronous reference frame models. Estimation is done assuming that the magnitude of the flux is available. A voltage model observer is used to estimate the αβ fluxes: these are used to compute the field-orientation angle and the flux magnitude. The paper develops an observer based on the first-order model; however, this does not perform well under parameter variations. A second observer is developed using an augmented model (which now involves the speed of the motor) - this is transformed into a sensorless design by feeding it with a speed estimate (assumed inaccurate). It is shown how to design the feedback gains in order to reduce the sensitivity of the estimate to the input speed error. The theoretical developments are supported with simulations and experiments.

Keywords: induction motor control; voltage model observer; sliding mode observer; rotor time constant estimation.

DOI: 10.1504/IJPELEC.2020.108385

International Journal of Power Electronics, 2020 Vol.12 No.1, pp.30 - 53

Received: 19 Nov 2017
Accepted: 13 Feb 2018
Published online: 13 Jul 2020 *

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