Aux 2 Unit 7 Load sharing Flashcards

What is a potential risk if one generator’s AVR fails to provide sufficient output while running in parallel?

C) The overall system voltage may fluctuate, leading to potential instability

Why is it essential for an AVR to maintain a stable voltage output?

C) To protect connected electrical equipment and ensure stable power delivery

What impact could a low output from an AVR have on connected equipment when a generator is running on its own?

C) The equipment may underperform or malfunction due to low voltage

If the excitation of one generator in a parallel system decreases, how does this affect the load sharing between the generators?

B) The generator with reduced excitation supplies less reactive power, and the other generator compensates

Why is it critical to ensure that the phases of two generators are in phase before closing the main circuit breaker?

B) To avoid mechanical torque shock and electrical surges

What would be the immediate effect if one generator’s AVR gives a low output while running in parallel with a second generator whose AVR is functioning correctly?

B) The generator with the faulty AVR will supply less reactive power

How does speed droop help maintain load sharing stability between parallel generators?

B) It allows each generator to adjust its power output proportionally based on its droop setting

How does an electronic governor maintain the speed of a diesel generator?

C) By altering the fuel supply based on feedback from the speed sensor

What component in an electronic governor receives feedback from the speed sensor to adjust the fuel supply?

B) Control unit

What happens when two generators with different speed droop settings are running in parallel and are sharing the load equally?

C) The generator with the higher droop setting will naturally take on more of the load

What is a potential effect on the system if one generator’s excitation is reduced significantly while operating in parallel?

C) The overall system voltage may decrease

What can be the effect on the mechanical parts of the generators if they are connected out of phase?

C) High mechanical stress and potential damage to the rotor and shaft

Why is load sensing important in the operation of an electronic governor for a diesel generator?

C) It enables the governor to adjust fuel supply and maintain speed under changing load conditions

What electrical phenomenon can occur if the main circuit breaker is closed while the generators are out of phase?

B) The generation of a high inrush current

What is the primary purpose of an Automatic Voltage Regulator (AVR) in an AC generator?

B) To regulate the generator’s voltage output

What is the primary purpose of the electronic governor in a diesel generator?

B) To adjust fuel supply to maintain desired engine speed and load balance

What effect would unequal droop settings have on frequency when generators are sharing an increasing load?

B) The generator with the higher droop setting would drop more in speed, causing a frequency imbalance

What happens if the speed sensor in an electronic governor fails?

C) The governor may not be able to properly adjust fuel, causing potential speed fluctuations or shutdowns

What would be the observed effect if an AVR gives a low output when a generator is running independently?

B) The generator’s output voltage will drop

What happens when the electronic governor detects an increase in load on the generator?

B) The governor increases fuel supply to maintain speed

What is the term "speed droop" in relation to an AC generator?

A) The difference between the no-load and full-load speed of a generator

What happens to the reactive power output of one generator if its excitation is reduced while the load on the system remains constant?

B) The generator’s reactive power output decreases

Why is speed droop important in the operation of AC generators in parallel?

B) To allow generators to share load proportionally

Which of the following is a primary component of a diesel generator's electronic governor?

B) Speed sensor

Which part of the electronic governor is responsible for making physical adjustments to the fuel supply in a diesel generator?

B) Actuator

What can occur if generators with different speed droop settings are running in parallel and the load suddenly increases?

B) The generator with the lower droop may become overloaded

How does a generator with a low AVR output affect the other generator when running in parallel?

B) The other generator will compensate by supplying more reactive power

What is the potential consequence of closing the main circuit breaker when the frequency and voltage are equal, but the phases are out of phase?

B) The generators may trip due to a phase mismatch

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