Design and Performance Analysis of Superconducting Rim-Driven Synchronous Motors for Marine Propulsion

Rim-driven thrusters have received much attention concerning the potential benefits in vibration and hydrodynamic characteristics, which are of great importance in marine transportation systems. In this sense, the rim-driven permanent magnet, brushless dc, and induction motors have been recently suggested to be employed as marine propulsion motors. On the other hand, high-temperature superconducting (HTS) synchronous motors are becoming much fascinating, particularly in transport applications, regarding some considerable advantages such as low loss, high efficiency, and compactness. However, the HTS-type rim-driven synchronous motor has not been studied yet. Therefore, this paper is devoted to a design practice of rim-driven synchronous motors with HTS field winding. A detailed design procedure is developed for the HTS rim-driven motors, and the design algorithm is validated applying the finite element (FE) method. The FE model of a three-phase 2.5-MW HTS rim-driven synchronous motor is utilized, and the electromagnetic characteristics of the motor are then evaluated. The goal is to design an HTS machine fitted in a thin duct to minimize the hydrodynamic drag force. The design problem exhibits some difficulties while considering various constraints.