Type of Document Master's Thesis Author Pradhananga, Shailesh Author's Email Address firstname.lastname@example.org URN etd-07082004-150137 Title Experimental Validation of a Smart Bias Active Magnetic Bearing Controller Degree Master of Science in Mechanical Engineering (M.S.M.E.) Department Mechanical Engineering Advisory Committee
Advisor Name Title Marcio de. Queiroz Committee Chair Wanjun Wang Committee Member Yitshak Ram Committee Member Keywords
- smart bias
- Shailesh Pradhananga
- magnetic bearing
Date of Defense 2004-07-05 Availability unrestricted AbstractActive magnetic bearings (AMBs) are being increasingly employed in the aerospace industry in a variety of devices including compressors, turbines, pumps, and flywheels. One application of great interest to future space missions is the Integrated Power and Attitude Control System (IPACS). The IPACS consists of an arrangement of flywheels that integrates the energy storage and attitude control functions into a single system; thereby, reducing the spacecraft mass, volume, launching cost, and maintenance.
Like any energy storage system, flywheels need to be operated with low power losses. AMBs are ideally suited for flywheels because they eliminate mechanical losses (friction). Nevertheless, AMBs are subject to electrical losses, which are proportional to the bias flux. We recently developed an innovative solution to the problem of AMB control with reduced electrical power losses. The controller incorporates a smart, time-varying bias flux that reduces power losses without affecting the rotor stabilization. The novelty of the smart-bias controller strongly motivated the pursuit of the next step in this research – an experimental validation. To that end, the objectives of this project were:
· Design and build an experimental AMB test rig.
· Conduct tests to validate the smart-bias controller and its power-loss reduction mechanism in comparison to a standard constant-bias AMB controller.
The experimental results show that the smart-bias controller clearly reduces the electrical power losses and energy dissipation of the AMB system in comparison to the constant-bias approach, without significantly affecting the stabilization performance. These results confirm, in a qualitative manner, the theoretical and numerical results obtained earlier.
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