Magnetic bearing control apparatus, control method and high speed rotating motor using the same

A high speed rotating motor, comprising:

• a stator configured to generate first electromagnetic force;
• a rotation shaft arranged inside of the stator and configured to rotate based on the first electromagnetic force;
• a magnetic bearing configured to float the rotation shaft from a surface of the magnetic bearing, the magnetic bearing comprising a plurality of output elements configured to generate second electromagnetic force and configured to enable the magnetic bearing to maintain a predetermined distance between the rotation shaft and the stator based on the second electromagnetic force;
• at least one displacement sensor configured to sense a displacement of the rotation shaft;
• a current sensor configured to detect a current supplied to the plurality of output elements;
• and
• a controller configured to:
• control a current supplied from the plurality of output elements to the magnetic bearing,
• control a position of the rotation shaft based on the displacement of the rotation shaft,
• determine a failure of the displacement sensor, and
• determine a failure of the plurality of output elements or the current sensor, wherein the controller is further configured to:
• perform a plurality of control cycles until the position of the rotation shaft corresponds to a set optimal control range,
• control the rotation shaft to move by a predetermined distance per each control cycle of the plurality of control cycles,
• sense the position of the rotation shaft in each control cycle,
• based on the position of the rotation shaft sensed in each control cycle, determine whether floating of the rotation shaft from the magnetic bearing has failed, and
• based on determining that the floating of the rotation shaft from the magnetic bearing has failed, determine a failure position of the current sensor or the plurality of output elements.