Patent ID: 6734650
Filing Date: 2004-05-11
Classification: F16C

Abstract:
An active magnetic bearing system for rotationally suspending a rotor having a center of gravity, comprising:at least two displacement sensors, each displacement sensor operable to (i) sense rotor displacements in a sensor frame of reference that is displaced from the rotor center of gravity and (ii) supply displacement signals representative thereof; a rotational speed sensor operable to sense a rotational speed of the rotor and supply a rotational speed signal; a controller coupled to receive the displacement signals from each of the displacement sensors and the rotational speed signal from the rotational speed sensor, and operable in response thereto to: (i) transform the displacement signals from the sensor frame of reference to a center of gravity frame of reference, (ii) generate correction signals according to predetermined gains to eliminate first and second linear displacements of the rotor's center of gravity and first and second rotational displacements around the rotor's center of gravity, (iii) vary the predetermined gains of at least the correction signals generated to eliminate the rotational displacements in a continuous non-linear fashion based on the received rotational speed signal, and (iv) transform the correction signals to an actuator frame of reference that is displaced from the rotor center of gravity; andat least two electromagnetic actuators coupled to receive the transformed correction signals and operable, in response thereto, to eliminate the sensed rotor displacements.