The goal of this master thesis is to derive a model of the induction machine
that drives the washing machine drum, a model for the drum with an unbalanced
load and to derive a controller for the induction machine. In addition
to the models, it should also be investigated if the currents, drawn by the
induction machine, will vary with the unbalanced load. Finally it should be
investigated if it is possible to determine the mass of the unbalanced load
simply by looking at the stator currents.
A vector control drive consisting of a current and a speed PI-controller
have been derived and implemented in MATLAB/Simulink. Two controllers
have been derived, one equipped with a flux estimator for speed sensored
control and the other with a flux and speed estimator for sensorless control.
The induction machine model and the model for the washing drum
with unbalanced load have been verified to work as intended. It was also
found that it should be possible to measure the currents, represented in the
synchronously rotating reference frame, drawn by the induction machine to
determine the size of the unbalanced load.
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