The Power Systems Group of L-3 Communications SPD Technologies division last month delivered a prototype power-conversion module, designated PCM-3, for use with the Navy's integrated "fight-through" power system (IFTPS) test bed in Philadelphia. The delivery and installation of the PCM-3 unit, which will act as a DC-to-DC converter within the IFTPS test bed, continues the Navy's movement toward what it hopes will be a revolution in shipboard power management.
The IFTPS test bed, formerly referred to as the integrated power system, is exploring power management technologies aimed at development of a shipboard integrated electric drive system that could be selected as the foundation for power architectures for future ships, beginning, potentially, with the DD(X) destroyer program. The next-generation cruiser, CG(X), is another distant target.
Electric drive for propulsion and ship systems has been named as a nonnegotiable goal for future surface ships and submarines by Secretaries of the Navy and Chiefs of Naval Operations going back at least a decade. Currently, integrated electric drive is one of a suite of technologies mandated for the DD(X), under contract to Northrop Grumman Ship Systems.
The IFTP's nickname is based on the requirement that the system be capable of "fighting through" casualties to a decentralized zonal power distribution arrangement. The IFTPS is managed by PMS-510 within the program executive office for ships, which also is running the DD(X) program. The test bed consists of a General Electric LM2500 gas-turbine engine, which powers a 22-megawatt commercial generator built by Brush Electric. Alstom Power Conversion provides a 19-megawatt induction motor and motor drive.
In addition to the PCM-3, General Atomics and DRS Power & Control Technology (formerly Eaton Navy Controls) have furnished other conversion modules, designated PCM-1, -2, and -4. The PCM-4 converts the 4,160 volts AC generated by the propulsion-generation system to 1,000 volts DC, and feeds it to port and starboard distribution systems. The PCM-1 converts the 1,000 volts DC to 900 volts, which then is converted by the PCM-2 to 440 volts AC for use by ship systems.
The IFTPS effort started in 1999 when Naval Sea Systems Command funded the participating companies for the program, which follows earlier testing at the Philadelphia site under the old integrated power system program.
Yet the IFTPS work, which is intended to provide technology options to industry ship designers, probably will not lead to a production system. Northrop Grumman officials have said they will not use the IFTPS for the DD(X). Instead, the company's Newport News Shipbuilding business unit is working with newly formed DRS Electric Power Technologies to provide the integrated electric drive architecture for DD(X).
The Newport News-DRS work builds on a partnership established in the early 1990s between Newport News and Kaman Aerospace Electromagnetics. The agreement remained intact when Northrop Grumman selected the Newport News-Kaman team for its electric drive design work during the DD(X) competition. In 2001, Northrop Grumman acquired Newport News and last year won the DD(X) contract.
Kaman, based in Hudson, Massachusetts, has designed high-torque permanent magnet motor technology that DD(X) program officials believe will be mature enough for the first of several "flights" of DD(X) ships. Kaman has continued work on design of a prototype motor and the required power electronics and converters. The company teamed with Power Technology of Fitchburg, Massachusetts, for integration and large-scale assembly of the motor and stator unit. The Newport News-Kaman team, however, still needed a partner for production of the system.
In mid-January, DRS Technologies acquired Kaman, and thereby a place on the DD(X) industry team. DRS had acquired Eaton Naval Controls, a longtime builder of Navy controls, last July. DRS then acquired Power Technology in February in a $35-million cash purchase.
The alliance of the Kaman, Power Technology, and Eaton business units within DRS gives DD(X) prime contractor Northrop Grumman the capability to provide the integrated electric drive architecture for the program without input from the Navy-funded IFTPS. In early March, Northrop Grumman awarded DRS an additional $2 million to continue design work aimed at the manufacture, qualification, and testing of the advanced PMM-based electric drive motor.
The IFTPS test bed will continue to look at electric-drive technologies, to "see what happens down the road," says one company official.