Stability of magnetic bearing-rotor systems and the effects of gravity and damping
- Univ. of Virginia, Charlottesville, VA (United States)
New and general stability criteria are developed for magnetic bearing-rotor systems under practical conditions of system operation and failure based on the Lyapunov second (direct) method. The unperturbed (fully nonlinear) stability of a conventional magnetic bearing-rotor configuration is analyzed for zero gravity; these results are shown to apply with gravity, based on observed similarities of the nonlinear Lagrangian equations. In addition to known results for stability and instability, the system can be stable when a magnetic bearing fails (has negative stiffness), but the net stiffness is still positive. A complete set of sufficient conditions are derived. This temporary stability depends upon inherent gyroscopic forces and is lost when dissipative forces are introduced. However, even with damping the gyroscopic forces improve the system`s relative stability. The results are applicable to other gyroscopic systems. 10 refs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 45855
- Journal Information:
- AIAA Journal, Journal Name: AIAA Journal Journal Issue: 7 Vol. 32; ISSN AIAJAH; ISSN 0001-1452
- Country of Publication:
- United States
- Language:
- English
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