AVRs are used in many ways as voltage regulators in conventional brushless synchronous generators.

The voltage regulator detects the output voltage of the generator, converts it into direct current, compares it with the set value, then adjusts the voltage. If a value different from the set value is detected, the strength of the excitation field is adjusted to maintain the rated voltage of the generator so that the rated voltage can be maintained at a constant value.

In addition, during load operation, the voltage input to the voltage regulator will drop due to the current consumed by the generator load. When the voltage regulator detects a voltage drop, the device increases the current of the excitation. When the load decreases, the voltage regulator detects a voltage rises and decreases the current of the excitation to stabilize the voltage.