Hexagram Rectifier—Active Front End of Hexagram Inverter for Medium-Voltage Variable-Speed Drives.

Recently, a new multilevel inverter—Hexagram inverter has been reported for medium-voltage (MV) variable-speed drives (VSDs). This paper will propose a Hexagram rectifier as the active front end for the Hexagram-based MV VSD systems. The control of the Hexagram rectifier is based on one-cycle control-an excellent control scheme for switching power converters. With the proposed control scheme, unity power factor at the source side can be achieved, the six modules will equally share the output power, and the voltage stress of the converter will be reduced six times. A 1-MW simulation model and a 1.2-kW experimental prototype have been built to demonstrate the proposed Hexagram rectifier and its control scheme. [ABSTRACT FROM AUTHOR]