Power Systems Quiz

How calculate the real power, reactive power and apparent power

• By impedance triangle

• By power triangle

• By power factor triangle

• None

Two power systems A and B are operating in parallel. If system A increases its generation to deliver 100 MW to system B, what will be the effect if system B does not reduce its generation simultaneously?

• frequency will increase

• frequency of both A and B will decrease

• frequency will remain unchanged.

• None

Governors for controlling the speed of power generation units provide

• A flat speed -load characteristics

• An increase of speed with increasing load

• A decrease of speed with increasing load

• None

When two identical a.c generating units are operated in parallel on governor control, and one machine has a 5% governor droop and the other a 10 % droop , the machine with the greater governor droop will

• Tend to take the greater portion of load changes

• Share load equally with the other machine

• Tend to take the lesser portion of load changes.

• None

On load-frequency control installations, error signals are developed proportional to the frequency error. If frequency declines , the error signal will act to

• Increase prime move input to the generators

• Reduce prime mover input to the generators

• Increase generator voltages

• None

Power system A is operating in parallel with other power systems and has a frequency bias of 50 MW per 0.1 Hz. For a loss of generation in one of the interconnected systems which results in a frequency drop of 0.03 Hz , power system A should

• Provide 30 MW of support

• Not be affected

• Provide 15 MW of support

• None

If a power system operates at an average frequency of less than 50 Hz,

• No time error will accumulate

• There will be a slow accumulated time error

• There will be a fast accumulated time error.

• None

When a power system operator observes an accumulated time error, he should correct it by

• Increasing generation on his system

• reducing generation on his system

• co-ordinating time error with other interconnected systems

• None

The sending end voltage of the transmission line controls the

• active power

• reactive power

• (A) and (B)

• None of the above

The frequency of the power system control the

• Active power

• Reactive power

• (A) and (B)

• None of them