A Series-Winding Topology Converter for the Magnetic Field Superimposed Magnetic Bearing

The power electronic drive is an essential component of a magnetic bearing system. It can rapidly change the current of the windings, thus controlling the dynamic changes of the electromagnetic force. This paper proposes a novel magnetic bearing power electronic drive based on a series-winding topology mainly used for magnetic field superimposed magnetic bearings. This topology can control the windings' bidirectional current and can be extended to an N-degree-of-freedom system with only 2N+2 switching devices. Compared to the conventional topology, this topology can reduce the cost of the drive, ensuring the current control capability. Moreover, this topology structure can evenly distribute the current of each winding between the bridge legs, reducing the current stress of the bridge legs compared to the common bridge-leg structure. The basic properties and control strategies of the series-winding topology are analyzed. Experiment and work verify the availability of the topology.