Digital Control for Active Magnetic Bearings in High-Speed Permanent-Magnet Synchronous Machine with 40000 rpm and 40 kW

Magnetic levitated rotational electrical permanent-magnet synchronous machines (PMSM) can reach a high speed due to its contactless rotor suspension with active magnetic bearings. Less maintenance is necessary due to the absence of mechanical bearings and its corresponding lubricants. The rotor dynamic as a MIMO-system (Multiple Inputs, Multiple Outputs), e.g. its stiffness and damping, can also be adjusted by an appropriate controller.
The main focus of this thesis is the digital control of the active magnetic bearings of the single machine M2. The digital control is designed by the method of state-space control of the LQ regulator. It uses weighting factors on the state- and input variables of the magnetic levitated rotor to reach a minimum cost function to determine the optimum controller. The estimation of unmeasured state variables is executed by Luenberger observer or Kalman filter. The various experiments up to the speed of 40000 rpm verifies the good performance of the digital control, that comprises of the state-space LQ regulator, the state estimators and the disturbance compensation.
The results, of the vibration of the levitated rotor and of the tests on the thermal behaviours with optimized electromagnetic and thermal design of the machine, shall serve as scientific proofs for the application of magnetic levitated electrical PM synchronous machine in the real technical systems. Beyond that intention, this thesis shall contribute to the acceptance of magnetic levitated electrical machines as emerging commercial products.