Simultaneous Rotor and Controller Tuning for Active Magnetic Bearings in Turbomachinery

In industry, the development of active magnetic bearing for supporting turbomachinery typically occurs after the rotor design phase. Despite the advancement in the active magnetic bearing controller design and tuning processes, certain turbomachines exhibit structural issues concerning the observability and controllability of rotor vibrational modes that makes the controller design critical. These issues often pose challenges that cannot be effectively addressed or optimized solely by designing the controller. This article introduces an innovative and practical approach that simultaneously tunes the controller and modifies some rotor characteristics, with the aim of improving the overall system performance. In practice, some small parts of the rotor structure are tuned together with controller parameters to modify the rotor dynamic behavior in accordance with the controller needs. The proposed technique leverages a non-smooth robust controller design methodology, capable of accommodating various system requirements, ultimately yielding locally optimal solutions to the design problem. To illustrate the practicality and effectiveness of this tuning method, we provide a detailed implementation on a turbo-compressor for oil and gas application and subsequently analyze the results, with a specific emphasis on its applicability.