Sensorless control of a matrix controlled variable speed DFIM

Abstract

In this dissertation the high performance sensorless control of a Doubly-Fed Induction Machine (DFIM) with rotor-side matrix converter is presented. Control algorithms were developed for the typical range of speeds of a Wind Energy Conversion System (WECS) which is one of the most widespread industrial applications of the DFIM. The rotor speed/position measurements necessary for vector control were obtained from a Model Reference Adaptive System (MRAS) sensorless algorithm. The voltage model block within the MRAS loop was modified using various techniqc:.es so as to compensate for offsets found in sensor measurements while keeping the error in the estimates to a minimum. The DFIM with the various MRAS configurations was tested in both simulations and experimental setup; detailed results for both environments are presented. Compensation techniques with which to mitigate the effects of harmonics in be experimental DFIM or the sensorless performance are also discussed.