Research on Fault Tolerant Operation of Multi-Winding Control Loop Failure in Active Magnetic Bearing System

Active magnetic bearing system is a complex control system of electromechanical integration. Normal operation of active magnetic bearing system usually needs to drive all winding loops to work simultaneously. However, once one of the winding loops fails, the rotor suspension will run out of control and cause an accident. In order to improve the reliability of the whole operation of multi-winding loop, a method which implements the fault tolerant for the winding control loop is proposed. First, according to the distribution strategy of the same magnetic force produced by the minimum power consumption, the magnetic force of the fault winding will be redistributed to other normal windings to maintain the basic suspension state of the rotor, so as to win the time of the rotor speed reduction and eliminate or reduce the loss caused by uncontrolled suspension at high speed. All the failure modes that can achieve fault tolerant control are categorized. Each fault type only needs to solve one current distribution matrix. Then the fault tolerant control of different fault modes in a multiwinding loop can be achieved through coordinate transformation and winding remapping matrix. Finally, the experiments demonstrates the effectiveness of this fault tolerant method.