Online-Identification of the Machine Parameters of an Induction Motor Drive

An approach to identify the induction motor parameters in parallel to the normal field-oriented controlled drive operation is presented. The aim is to perform the parameter estimation in the whole operating range and not only for specific operating conditions. Besides an overview of suitable system identification methods, the parameter estimation approach combined with an FIR-filter to determine the derivatives of measured signals is analyzed in detail. All filtered signals are processed using the recursive least squares method to estimate the parameter vector. This approach shows highly promising performance, is comparatively simple and less computationally intensive compared to alternative approaches, i.e. the extended Kalman filter or the unscented Kalman filter for combined state and parameter estimation.