Comparative Study on Topologies of Three-Level and Open-Winding Converters for PMSM Drives

This paper conducts a comparative study between three-level and open-winding topologies for permanent magnet synchronous machine (PMSM) drives. Since three-level and open-winding topology converters have the same voltage vector distribution pattern, they all have the capability of multi-level output. Moreover, for three-phase three-level converter and three-phase open-winding converter, they all use twelve switching devices. However, since their structures are different, there are some differences in modulation strategy, current performance, dc-link voltage utilization, and system capacity between these two topologies. Thus, this paper mainly focuses on their differences, and presents the detailed comparison. The three-level converter is more suitable for high-power density and high-performance applications which requires the higher integration. For open-winding converter, applications are more suitable for fields of high-power capacity, high dc-link voltage usage.