Drives and Controls Magazine
Cell-based medium-voltage drives offer design flexibility
Published:  14 July, 2014

Siemens has announced a series of medium-voltage drives in which low-voltage cells are linked together to build the MV power output. This allows the Sinamics Perfect Harmony GH150 drives to be scaled for output voltages from 4–7.2kV and output ratings up to 13.3MVA.

The liquid-cooled drives, available in 12–36 pulse designs, are suitable for use in integrated drive systems. The use of separate transformers and control cabinets offers flexibility in their placement and allows the transformers to be chosen for any primary voltage. The transformers can be installed in locations with easy access or good cooling conditions.

The modular design is also said to improve system efficiency, and to minimise the required footprint. The control cabinet can be installed separately from the MV power section – possibly in an LV control room – making operation and maintenance simpler and safer. Failed cells can be bypassed during operation to maintain output voltages.

Siemens' Perfect Harmony MV drives have a flexible, modular architecture

The drives have marine certification and are arc-fault-tested, making them suitable for marine, offshore, and oil and gas applications.