How is the direction of propeller shaft rotation changed when directly coupled to an AC synchronous motor when driven by a variable frequency alternator in an AC turbo-electric drive system?

Correct Answer: Option B — Reversing the phase sequence of power to the motor

In AC turbo-electric drive systems, the direction of the propulsion motor is reversed by changing the phase sequence of the power supplied to the stator. By interchanging two of the three phases, the direction of the rotating magnetic field is reversed, forcing the synchronous motor to change rotation.