-American Superconductor Corporation (NASDAQ: AMSC), a leading energy technologies company, and Northrop Grumman Corporation (NYSE: NOC) announced today at the Surface Navy Association’s 21st National Symposium the successful completion of full-power testing of the world’s first 36.5 megawatt (49,000 horsepower) high temperature superconductor (HTS) ship propulsion motor at the U.S. Navy’s Integrated Power System Land-Based Test Site in Philadelphia. This is the first successful full-power test of an electric propulsion motor sized for a large Navy combatant and, at 36.5 megawatts, doubled the Navy’s power rating test record.
Incorporating coils of HTS wire that are able to carry 150 times the power of similar-sized copper wire, the motor is less than half the size of conventional motors used on the first two DDG-1000 hulls and will reduce ship weight by nearly 200 metric tons. It will help make new ships more fuel-efficient and free up space for additional warfighting capability.
“The successful load test of our HTS motor marks the beginning of a new era in ship propulsion technology,” said Dan McGahn, senior vice president and general manager of AMSC Superconductors. “This motor provides the U.S. Navy with a truly transformational capability relative to size, stealth, endurance and survivability, providing our Navy with a clear performance advantage for years to come. We are grateful for the steadfast support from the Office of Naval Research, Naval Sea Systems Command and the Naval Surface Warfare Center.”
Degaussing Coil for Less Magnetic Signature and More Weight Savings
Earlier in 2008, the Navy successfully installed another HTS system – an HTS degaussing coil – onboard the USS HIGGINS (DDG 76). Powered by AMSC’s HTS wire and magnet cable technology, the coil system will undergo sea trials over the next two years onboard the HIGGINS. Similar to the motor, degaussing coils utilizing HTS wire will significantly reduce system weight for DDG 1000-class ships, landing platform dock (LPD) ships, and for the Littoral Combat Ships (LCS).
Degaussing systems containing multiple tons of copper wire are utilized in most naval ships to cloak their magnetic signature, thereby making them much more difficult to be “seen” by magnetic sensors and magnetically activated mines. These systems are composed of a network of electrical cables installed around the circumference of a ship’s hull, running from the bow to the stern on both sides of
“The work on the Higgins represents a true leap ahead for the U.S. Navy magnetic silencing and HTS communities that takes advantage of two decades worth of research,” said ONR program manager George Stimak. “HTS degaussing brings with it a new capability in not only being able to perform the same functionality that legacy copper-based degaussing systems can accomplish but being able to do the same task in a much more efficient manner that is less invasive to the ship. It opens up the design trade space for the naval architect in planning out the degaussing system to meet the platform’s signature requirement. The Navy’s adoption of the technology is a result of many years of hard work in developing HTS wire and demonstrations funded by both the Department of Defense and the Department of Energy.”
AMSC produces HTS wires that conduct more than 150 times the electrical current of copper wires of the same dimensions. With this “power density” advantage, the Navy estimates that HTS degaussing systems projected for the LPD-17, LCS, CG(X), DDG-1000, and CVN-21 classes of ship will show a 50%-80% reduction in total system weight
and a reduced total ownership cost compared to the current copper-based systems. In addition, a 90% reduction in the total installed cable lengths for all Navy ship classes is expected.
Office of Naval Research website The Superconducting motor is the code 33 technology section.
The HTS ship propulsion motors offer a range of benefits and advantages for both naval and commercial shipping applications including the following:
• Up to three-times higher torque density than alternative technologies, HTS machines are more compact and lighter in weight. The size and weight benefits make HTS machines less expensive and easier to transport and install, as well as allowing for arrangement flexibility in the ship.
• Absence of iron stator teeth reduce the structureborne noise
• High efficiency from full-to-low speed, boosting fuel economy, sustained speed, and mission range, all key mission parameters for warships.
• Isothermal field winding is well suited for repeated load changes
A typical Navy ship, such as the DD(X) destroyer, needs two propulsion motors, each rated at 36.5 MW, 120-rpm. Such large motors have been built using conventional technology but they are four to five times heavier than the ONR funded 36.5 MW HTS motor being built by AMSC.
Sumitomo demonstrated a small superconducting motor for an electric car in 2008 and continues working on commercializing that technology for cars and trucks. The company says the prototype vehicle can travel more than 10% farther than conventional electric vehicles running on the same type of battery.