Open-circuit Fault-tolerant Control Strategy of Five-leg Drive in Active Magnetic Bearing

Active Magnetic Bearing (AMB) is widely used in high-speed rotating machinery, which has high requirements for safety and stability. Power electronic amplifier working with high voltage/current stress is one of the most vulnerable parts of the AMB system. The strategy this paper proposed can achieve its open-circuit fault tolerance, including fault detection, fault location and fault tolerant mode switching. This strategy ensures that the magnetic bearing rotor before and after the failure to maintain stable suspension, making the whole system without stopping operation. Firstly, the control method of the five-leg drive and the fault-tolerant mode are proposed. Then, the phenomenon when fault occurs is analyzed, strategy for fault detection is introduced. Results of simulation and experiments show effectiveness of fault tolerant by the proposed fault tolerant strategy.