Power Conversion Equipment: Militarized Drives

Ultra's Power Dense Naval Drive (PDND) is a highly flexible, general-purpose motor drive for high power (100-400HP) applications in an exceptionally small enclosure. This solution takes advantage of the advances made in the inverter technology within the commercial marine market. It uses the latest thermal, electrical and mechanical modelling techniques to deliver a fully capable, highly power dense solution suitable for the military environment.

Primarily dictated by the power quality requirements of Mil-Std-1399, the PDND is a fully regenerative, four-quadrant variable speed drive system incorporating a PWM front end to ensure that the harmonic distortion imposed on to the supply is less than 3%. This also provides the benefit of being able to operate at near unity power factor throughout the speed range.

The PDND is flexible and programmable, making it suitable for a wide range of induction and permanent magnet motors. Communication and remote control of the drive is available in all industry standard data formats.

The Fire Pump Motor Drive for the USS Wasp is a forced-air cooled 375HP (280kW) PDND. Its small footprint enables it to be fitted through the ship's hatches, making for a highly cost-effective installation.

Water-cooled variants for sealed enclosures are also available.

Specialized Motor Drives

The Mooring Capstan Controller for the Virginia Class Submarines demonstrates EMS's capability to supply specialized variable-speed drives to meet the particular demands of the submarine environment: non-standard control and feedback requirements, integrated ancillary functions, highly detailed hardware and software ILS requirements.

It achieves this through a modular design featuring scalable, configurable building blocks, suitable across a wide range of ratings, applications and motor types, and EMS's long association with submarine requirements.