Precise Digital Control of Active Magnetic Bearings

This book presents a step by step approach in
developing a test rig for the acoustic noise study
of induction machines using Active Magnetic Bearings
(AMB). The possibility of developing a DSP based
digital control system for this purpose is
presented. The AMB system is
initially modeled using first principles using
manufacturer data. Controller designs are carried
out first at simulation level. Successful
implementation of the digital controller
opens up several opportunities for further research.
One of them is the model validation using system
identification tests. Under this, the mathematically
developed AMB model is validated in time domain and
frequency domain by conducting system identification
experiments. Periodic disturbances occur in the
position feedback signals, when the motor is
rotated. An adaptive periodic disturbance
cancellation method is employed to overcome this
problem. This further improves the performance of
complete control strategy. As such, the modeling and
control strategies used in this book can be used as
the basis for anybody entering into the area of AMB.