Dynamics of high-power multi-rotor system

Abstract Typically, active magnetic bearings have been applied to high-speed rotors in medium to high power range to replace ball, roller, and oil-film bearings. They require less maintenance and provide number of unique benefits owing to contactless suspension and active control. Integrated compressor or turbines result in predictable rotor dynamics. This allows use of model-based controllers. The model-based centralized controllers outperform decoupled transfer function controllers, but they do require accurate plant models. For integrated wheels on a single rotor the control models comprise a rigid rotor and lowest frequency bending modes. The bending mode parameters related to node locations can be identified yielding controllers tuned to the applications. This work introduces drive train modelling and magnetic levitation control of 2 MW rotor and external load with flexible coupling. The model-based control is tested in the experimental setup and drive train frequency responses are compared to the modelled multi-rotor drive train dynamics