5 MW High Temperature Superconductor Ship Propulsion Motor Design and Test Results

American Superconductor has designed, built, tested and delivered to the U.S. Navy's Office of Naval Research (ONR) a 5MW, 230‐RPM, 6‐pole high temperature superconductor (HTS) ship propulsion motor. The motor uses an air core armature winding and first generation HTS wire (BSCCO‐2223) field winding. The goal of the motor development project was to validate the technologies required to design and build larger HTS ship propulsion motors, as well as to develop a motor production process that streamlines development time and minimizes cost. A commercial variable frequency drive is used to power the motor. The HTS field winding is cooled with G‐M coolers with gaseous helium as the cooling medium in a closed cycle. The armature is cooled by Midel®. The motor was delivered to the U.S. Navy in July 2003 and met or exceeded requirements in operation (up to the facility's testing limit of 2.5MW). The motor demonstrated both full torque and full speed operation in separate tests.