HTS – The Future of Navy Motors

36.5 MW motor construction.jpg
American Superconductor Corporation recently announced the successful completion of factory acceptance testing for the world’s first 36.5 megawatt (49,000 horsepower) high temperature superconductor (HTS) ship propulsion motor at Northrop Grumman’s facility at the Philadelphia Naval Business Center. This is the final milestone before the Navy takes possession of the motor.

The motor was designed, developed and manufactured under a contract from the U.S. Navy’s Office of Naval Research (ONR) to demonstrate the efficacy of HTS primary- propulsion-motor technology for future Navy all-electric ships and submarines. The power and torque of this HTS motor is comparable to the requirements for the Navy’s new Zumwalt class of destroyers, known as DDG 1000. In comparison with the conventional copper motors being used on the first two DDG 1000 hulls, the HTS motor is less than one-half the size and weight, and is more efficient over a much wider range of ship speeds. This results in weight and space advantages, enabling an increase in payload capacity for both naval and commercial vessels.

Why HTS?
High Power Density: The HTS field winding produces magnetic fields higher than those of conventional machines resulting in smaller size and weight.
High Partial Load Efficiency: HTS motors have higher efficiency at part load (down to 5% of full speed), that results in savings in fuel use and operating cost. The advantage in efficiency can be over 10% at low speed.
Low Noise: HTS motors have lower sound emissions than conventional machines.
Low Synchronous Reactance: HTS air-core motors are characterized by a low synchronous reactance which results in operation at very small load angles. Operating at a small load angle provides greater stiffness during the transient and hunting oscillations.
Harmonics: HTS motors generate voltages free of harmonics.
Cyclic load insensitivity: HTS motor field windings operate at nearly constant temperature unlike conventional motors and, therefore, are not subject to thermal fatigue.
Maintenance: HTS motors compared to conventional motors will not require the common rotor overhaul, rewinding or re-insulation.
(Source: American Superconductor)


  • elizzar

    hi there, think the highest temp. for superconductors at the moment is still about 80 degress kelvin, around liquid nitrogen temperature [i await to be corrected ;)]. a superconductor that could operate at ‘room’ temperature would revolutionise far more than just ships – imagine electricity grids carrying power across countries without any loss, for instance (that’d help the climate change gubbins!). the superconductors i have experience of are still very low temp, around 4 K, liquid helium cooled. cheers!

  • Thanos

    If they can make motors this way, then perhaps the obverse is true and they can make more efficient generators as well.

  • sailorcarrcreek

    the savings will be substantial . nearly every aspect has been thought out . the high tech super conductor motors will give a combat effective and commercial shipping advantage . speed not sacrificed . less wt to transport . less storage room occupied . because of super conductivity – less energy required . less shipping transport fuel cost . technology upgrade marketable to friendly forces and trans global shipping enterprise . ya reckon we could raft the Big Sandy from Pike all the way to the Mississippi , my Huckleberry Friend ? the generators could feed off the motor and download to the capacitor and battery back up . the super conductor insulation should require less energy to transfer energy into work . noise level may be decreased . less maint. for less parts . commercial spin off for the economy . military industrial relationships create more jobs . they produce R+D and make more revenues to pay for the government .

  • Charlie

    Ok, thats all very interesting, but think of the tanks! I mean, Why not strap one of em big boys on the bottom of a tank an create a new kind of battle ship we would have people all over the world envying or great idea, might even make millions, so! I got the duck tape lets put her together!.


    Thats fantastic, that you have make a bigest HTS motor.