Question 262Electricity/Electronics - 1st Asst/Chief70% to pass
An AC diesel-electric drive ship with synchronous propulsion motors has the capability for power factor correction. If the power factor associated with the main power distribution including all motors is 0.7 lagging, what statement is true?
AI Explanation
The correct answer is A) The synchronous propulsion motors are under-excited.
In an AC diesel-electric drive ship with synchronous propulsion motors, the power factor of 0.7 lagging indicates that the system is operating with a lagging power factor. This means that the reactive power is leading the active power, which is typically caused by an under-excited synchronous motor.
The other options are incorrect because:
B) The excitation status of the synchronous motor cannot be determined from the given information.
C) Over-excited synchronous motors would result in a leading power factor, not a lagging power factor.
D) Normally excited synchronous motors would result in a power factor closer to unity, not 0.7 lagging.
Related Questions
#260 A common method used to control the speed of a synchronous AC propulsion motor on a diesel-electric propulsion drive is by what means? #261 While standing an "at sea watch" onboard an AC diesel-electric drive ship with a synchronous propulsion motor, you notice that the kwatt load is at roughly 75% of capacity with a leading power factor less than 1. Ideally what would be the character of the power factor associated with the main power distribution including all motors? #263 An AC diesel-electric drive ship with synchronous propulsion motors has the capability for power factor correction. If the power factor associated with the main power distribution including all motors is unity #264 While underway onboard a DC diesel-electric drive ship, you notice excessive sparking of the brushes on the main propulsion motor. What should be your FIRST action? #265 While standing "at sea watch" onboard a modern rectified DC diesel-electric drive ship you notice the transformer core temperature slowly rising. What should be your FIRST action?