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This thesis investigates the controller parameter tuning
method for both a closed-loop vector-controlled and a sensorless
vector-controlled induction motor drives. Asystemmatic procedure
based on root-locus and frequency renponse techniques is
proposed to tune the controller parameters. The thesis
also proposes the design of a rotor flux observer for
improving the low-speed performance of sensorless
vector-controlled drive. In hardware
implementation the 80196MC single-chip micro- processor is
used for control software development. In estimatingthe rotor
flux, the actual stator voltages are not measured, insteadthe
stator voltage commands are used. The cost of the system
isreduced since no voltage sensor is used for stator voltage
sensing.Also, the rotor flux is estimated using the rated flux
value and alow-pass filter so as to compensate the deviation
caused by theintegrator during low-speed operation. Adeadtime
compensationcontrol board is added to the hardware, which
results in goodperformance during low speed with loads.
The experimental results show good performance for both the
closed-loop and the sensorless vector-controlled drives under
no-load and loading conditions at various speeds.
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