Design and implementation of a MRAS sliding mode observer for the inverse of the rotor time constant of the induction motor

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The paper presents an estimator for the inverse of the rotor time constant of the induction motor. Estimation is done using a sliding mode observer under the assumption that the stationary frame fluxes are known. With measured voltages, currents, and with known fluxes and speed, the paper develops an MRAS-type sliding mode observer. This works well under ideal conditions; however, if the speed is inaccurate or if the magnetising inductance saturates, the accuracy suffers. The paper develops a model for the saturated induction motor and attempts to also estimate the saturation level. In the second part, an observer with only a single set of feedback terms is developed. This is transformed into a sensorless observer by feeding it with a speed estimate (assumed inaccurate). The error in the estimated rotor time constant can be reduced by operating the motor drive with a low ratio of id to iq.

Original languageEnglish (US)
Pages (from-to)52-78
Number of pages27
JournalInternational Journal of Power Electronics
Issue number1
StatePublished - Jan 1 2018


All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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