A series-winding topology converter with capability of fault-tolerant operation for active magnetic bearing drive

Magnetic bearing is an important part of modern high-speed rotating machinery. The performance of power electronic converter highly determines the quality of magnetic bearing drive. In this article, a fault-tolerant converter with series-winding topology is introduced. Compared with the traditional topology, the current stress of phase leg is reduced while the utilization of dc voltage is guaranteed, and fault-tolerant operation can be realized in the case of open-circuit fault of the switching device. This article introduces the characteristics of the series-winding topology and the current control method. Open-circuit fault detection methods and countermeasures are also analyzed. Experimental results show the effectiveness of the proposed topology. Fault-tolerant experiments under static suspension and rotation of the rotor demonstrate the performance of the topology. This kind of series-winding topology provides a new scheme with good performance and high reliability for the design of magnetic bearing controllers.