Rockwell Automation has extended the power range of its PowerFlex 755 AC drives to 900 kW as well as adding 690 V ratings. The new drives, suited to a variety of heavy industrial applications, provide users with increased application flexibility, advanced diagnostics and a common DC bus option. Rockwell claims the extended range will help heavy industrial users reduce costs through improved flexibility, reduced downtime and low meantime to repair.
The common DC bus option allows users to connect the drive to a common DC bus configuration, taking advantage of different drive cycles to share energy. In this configuration, a DC bus acts as a common energy source that feeds energy from a generating load to a motoring load. Managing energy from a shared source increases overall system performance and reduces losses, which can improve the application’s energy efficiency.
The PowerFlex range includes an embedded ethernet port and five option slots. Option modules include I/O, feedback, safety, additional communications and an auxiliary power supply. A rollout design allows easy access to the drive for fast installation and maintenance. The drive’s converter and control pod remain in the unit while the inverter is rolled out, so control wiring can remain connected.
In addition to the extended power range, a firmware upgrade for all PowerFlex 755 drives will contain interior permanent magnet motor control and a ‘stop dwell’ feature, which helps prevent a motor from coasting to a stop. This is suitable for converting applications, as it allows users to preconfigure the motor to perform a controlled stop to protect valuable motor investments.