Performance of Twin-Rotor DC Homopolar Motor

A new concept of dual-rotor motor with counter-rotating propeller increases the efficiency of the ship propulsion used in marine industry. This concept can be realized by twin-rotor permanent magnet homopolar disc motor, which is the object of this work. The objectives of this work are to determine the motor electromechanical parameters applying a 3-D FEM modeling and to analyze the motor performance in steady-state and dynamic conditions. From the analysis, the following conclusions were deduced: - To produce the relatively high electromagnetic torque a very high currents have to be supplied to the rotor aluminum discs what is the major deficiency of the motor - The currents are distributed non-uniformly in the disc what makes the electromagnetic torque smaller. To improve this, more brushes should be applied around the disc periphery. - The proposed construction of the motor allows one rotor disc to rotate in direction opposite to the rotation of other rotor disc. This can be done by reversing the current flow in one of the aluminum discs.