Software For System For Controlling A Magnetically Levitated Rotor(LEW-17293-2)

FATMaCC (Five-Axis, Three-Magnetic-Bearing Control Code), is a versatile control code that possesses many desirable features that were not available in previous in-house controllers. The ultimate goal in designing this code was to achieve full rotor levitation and control at a loop time of 50 s. Using a 1-GHz processor the code will control a five-axis system in either a decentralized or a more elegant centralized (model control) mode at loop time of 56 s. In addition, it will levitate and control (with only minor modification to the input-output wiring) a two-axis and / or a four-axis system. Stable rotor levitation and control of any of the system mentioned above are accomplished through appropriate key presses to modify parameters, such as stiffness, damping, and bias. A signal generation block provides 11 excitation signals. An excitation signal is then superimposed on the radial bearing x- and y- control signals, thus producing a resultant force vector. By modulating the signals on the bearing x0 and y- axes with a cosine and sine function, respectively, a radial excitation force vector is made to rotate 360 about the bearing geometric center. The rotation of the force vector is achieved manually by using key press or automatically by engaging the " one-per-revolution" feature. Rotor rigid body modes can be excited by using the excitation module. Depending on the polarities of the excitation signal in each radial bearing, the bounce or tilt mode will be excited.magnetic bearings are an enabling technology for rotating devices with extremely high rotational speeds, such as flywheel energy storage systems being proposed for the International Space Station. In addition these bearings have great potential for conventional gas turbine engines especially because the control algorithms can compensate for an event such as loss of a blade that causes rotor imbalance.