VARIABLE SPEED DRIVE SYSTEM AND METHOD FOR STARTING AND/OR OPERATING A VARIABLE SPEED DRIVE SYSTEM

摘要

A variable-speed drive system includes a driven machine mechanically coupled to a drive machine by a transmission unit. At least two regulating machines are mechanically coupled to the transmission unit and operated by at least two frequency converters. At least one of the at least two frequency converters is electrically connected to the drive machine by a changeover device, wherein a connection of the drive machine to at least one electric supply network is at least temporarily disconnectable to produce a controlled speed change on the drive machine.