Dual Stator/Rotor Brushless DC Motors: A Review of Comprehensive Modelling Based on Parametric Approach and Coupled Circuit Model

This paper proposes a dual-rotor brushless direct-current motor design specifically realized for unmanned underwater vehicles. Brushless DC motors are known for their high torque capacity and power density specs which are also suitable for underwater drive trains known as thrusters. Proposed brushless DC motor model having double rotor and double stator structure is basically designed by applying typical design procedure including sizing equations followed by detailed parametric analysis approach and coupled circuit model. Design of a dual-rotor brushless DC thruster having foregoing structure utilizes modular concentrated winding, optimized slot-opening and pole/slot ratio, outer and inner diameter and etc. Main output parameters such as rated torque, rated power, rated speed and total loss parameter of each brushless DC motor for different rotor positions are computed and compared. Additionally, a coupled-circuit analysis is employed to show the impact of the proposed design to evaluate rated power and torque capability.