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Dynamic control of brushless doubly-fed machines

This thesis presents the development of dynamic control strategies for the
brushless doubly-fed machine (BDFM). A simple open-loop scalar controller is first
investigated and its response is found to be oscillatory. Using the speed feedback
signal, an improved closed loop scalar control algorithm is designed. Steady state
performance is controlled by the magnitude of the BDFM control winding current.
Simulation and experimental results demonstrate that the closed loop algorithm has a
slow response and is suitable for low performance drive applications. A model
reference adaptive control algorithm is investigated in simulation, attempting to improve
the BDFM dynamic response and assure its robustness against system parameter
Further investigations reveal that the field orientation principle for conventional
induction machines can be adapted for the BDFM. This enables the design of a rotor
flux oriented control algorithm, based on a newly established synchronous reference
frame model. Simulation results illustrate the algorithm's fast dynamic response and
robustness against parameter variations.
The verification of various control algorithms is carried out on a laboratory
system consisting of an experimental BDFM, a power converter and associated control
hardware. An Intel 80196Kr microprocessor is used to implement inverter switching
and current regulation for the BDFM control winding. The rotor flux oriented control
algorithm is implemented using an Intel 80960KB floating point microprocessor,
achieving a control bandwidth in the kHz-order.
Evaluation of a BDFM synchronous angle shows its significance in control
design, and it is incorporated into the later control algorithm development in order to
eliminate electric torque estimation. This simplifies control algorithm design and is
verified experimentally. Consequently, the control algorithm for the BDFM can
approach the simplicity of equivalent induction machine control techniques. / Graduation date: 1996
Date30 October 1995
CreatorsZhou, Dongsheng, 1964-
ContributorsSpee, Rene
Source SetsOregon State University
Detected LanguageEnglish

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