A Novel Multilevel Converter as Active Magnetic Bearing Drive Based on Hybrid NPC With Flying-Capacitor Leg

Multilevel power conversion technology represents a significant advancement in the field of power electronics, and the active magnetic bearing (AMB) drive is a typical power electronics equipment. This article introduces a novel hybrid neutral point clamped (NPC) multilevel AMB drive that incorporates a flying-capacitor (FC) leg, merging traditional NPC structures with the FC configuration. It upgrades the voltage levels of the magnetic bearing (MB) windings from three to five levels, thereby enhancing the system's voltage capacity and facilitating swifter current response times. Additionally, at the same voltage level, this approach improves the electromagnetic interference (EMI) characteristics of the AMB drive, diminishes current ripple and power loss, and improves the suspension precision of the MB. The efficacy of the proposed topology and its control methods has been rigorously validated on a MB blower experimental platform, demonstrating their practical applicability and performance benefits.