Which of the following statements is true concerning a large polyphase synchronous main propulsion motor as used in an electric propulsion drive system?

Correct Answer: Option C — The motor is started as an induction motor.

Large synchronous propulsion motors are typically started as induction motors using a squirrel-cage winding embedded in the rotor poles. Once the motor reaches near-synchronous speed, the DC field is energized to pull the motor into synchronism, preventing the high inrush currents associated with direct-on-line starting.