Question 261Electricity/Electronics - 1st Asst/Chief70% to pass
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?
AI Explanation
The correct answer is B) unity.
The power factor of the main power distribution should be unity (1.0) for an AC diesel-electric drive ship with a synchronous propulsion motor. This is because synchronous motors can be operated at a unity power factor by adjusting the field current to maintain the desired power factor.
The other options are incorrect because: A) zero power factor is not desirable, C) lagging power factor would indicate that the system is drawing more reactive power, and D) leading power factor, while better than lagging, is still not the ideal unity power factor.
Related Questions
#259 By what common means is the speed of the AC propulsion motor on a diesel- electric propulsion ship controlled? #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? #262 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? #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?