How is the speed of the propeller shaft directly coupled to an AC synchronous drive motor changed when powered by either a dedicated or integrated constant frequency alternator in an AC diesel- electric drive system?
• Synchronous motor speed relationship with frequency and number of poles • Behavior of a constant-frequency alternator in a diesel-electric system • Role of a power converter between the alternator and the motor
• For a synchronous AC motor, which quantities in the speed formula are fixed once the motor is built, and which can be changed during operation? • If the alternator is designed to be constant frequency, which of the options would actually remain constant and which could realistically be varied in normal operation? • Which device in the system is specifically intended to condition or modify electrical power before it reaches the motor?
• Write down the synchronous speed formula and identify which term each answer choice would affect; check which can be changed without redesigning hardware. • Consider what a constant-frequency alternator means for choices involving generator speed and field strength. • Ask yourself which component in the list of options normally has the job of controlling what the motor sees at its terminals in a modern AC diesel-electric drive.
No comments yet
Be the first to share your thoughts!