OPTIMAL FREQUENCY SELECTION FOR DESIGNING A SUPERCONDUCTING RIM-DRIVEN PROPULSION MOTOR

Abstract

Electrical propulsion systems have been developed in marine transportation in recent decades. Generally, an electric propulsion system consists of an induction, permanent magnet or conventional synchronous motor that is supplied by a DC batteries set and inverter-based drive system. Therefore, the working frequency of the propulsion motor and drive system can be considered as an arbitrary parameter. This paper deals with selecting the best rated frequency to minimize the losses of a superconducting rim-driven propulsion system. Several loss components of a case study motor are analyzed in rather wide-range of possible rated frequencies. The optimum frequency for designing the case study motor is then determined, and the motor is redesigned. Comparing the main performance characteristics of the new motor and original one shows a considerable decrement in total losses of the propulsion motor and drive system.