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S7-Q160.) Which of the following are adjustments on voltage regulators?

a.) Droop level
Yes, droop is monitored and corrected to maintain the desired percent regulation
(%Reg = VFULL LOAD – VNO LOAD x 100/ VFULL LOAD).
b.) Stability
Yes, the voltage regulator utilizes a network that is frequency sensitive. It consists of lag and lead
circuits to ensure the VR does not correct the system too fast or too slow.
c.) Gain
Yes, the excitation system must have a high gain and may be adjusted for specific applications.
d.) *All of the above
Correct. Each of the above answers are adjustments of voltage regulators.

S7-Q161.) Droop adjustment on a voltage regulator requires it to be under which type of load?

a.) Resistive
Incorrect
b.) *Inductive
Correct
c.) Capacitive
Incorrect
d.) No-load
Incorrect

S7-Q162.) Voltage regulators are not used on which type of generators?

a.) Self-excited generators
Self excited simply means that it does not have an external field. It still, however, requires regulation.
b.) *Induction generators
Correct. The induced voltage is a function of the pilot exciter and is controlled by the level of
excitation.
c.) Brush type generators
Some brush type (older) generators used large rheostats, but this is still a form of voltage regulation.
d.) All generators must use voltage regulators for safety purposes
Incorrect response. Induction or brushless generators do not require VRs. See answer B.

S7-Q163.) Which of the following is NOT an option available on voltage regulators?

a.) *Kilowatt control
Correct. This is a function of the governor and prime mover capability.
b.) Volts per Hz control
A generator operating at a rated voltage with constant excitation will follow what is known as the
Volts/Hz curve. This should be perfectly linear and adjustments are made to keep it linear.
c.) PF control
This is a function of current and voltage produced and is controlled, in part, by the voltage regulator.
d.) VAR control
This is part of PF control.

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