Question 263Electricity/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 unity
AI Explanation
The correct answer is D) The synchronous propulsion motors are over-excited.
When the power factor associated with the main power distribution of a diesel-electric drive ship with synchronous propulsion motors is unity, it indicates that the synchronous motors are operating at a leading power factor. This means the synchronous motors are over-excited, which allows them to compensate for the lagging power factor of other loads in the system, resulting in a unity overall power factor.
The other options are incorrect because:
B) The excitation status of the synchronous motor can be determined to be over-excited when the power factor is unity.
C) The synchronous propulsion motors are not normally excited, as they are operating in an over-excited state to achieve unity power factor.
Related Questions
#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? #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? #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? #266 When a transformer is used to step down voltage, what statement is true?