Study on Homopolar Superconductivity Synchronous Motors for Ship Propulsion Applications

Superconductivity synchronous motors compared with conventional motors can reduce the motor size and enhance the motor efficiency for low-speed and high torque applications under the space constraints for propulsion system. Especially, homopolar superconductivity synchronous motors (HSSMs) need less superconductor and lower magnetic flux density in superconductor field coil than air-cored superconductivity synchronous motors (ASSMs). In addition, mechanical structure is more simplified and stability is increased because the superconductor field coil of HSSMs is not rotated in operation. In this paper, we present the outline of HSSMs including structure, characteristics and operational principles with the conceptual design of HSSM.