Like the frequency, the generator voltage is also of particular importance for consumers and is an important indicator of the efficiency and life of the equipment. The voltage of the synchronous generator changes according to its excitation current; Therefore, to stabilize the voltage of the generator, its excitation current must be controlled according to the changes in the stabilized load and the reactive power of the generator output. Therefore, a control mechanism to stabilize the voltage and control the reactive power is installed in the diesel generator, which is called a voltage regulator or AVR. The functions of the automatic voltage regulator are listed below, based on the model used in the generator, all or part of these functions are used:
Voltage regulation
Reactive power control
Power factor correction
Gradual increase in voltage during startup
Stability control of the excitation system
Protection against decrease or increase of excitation current and voltage
Frequency reduction protection
limit the flow of excitation
The AVR receives the voltage generated by the generator stator as a sample and compares it with the set value and based on that, determines the amount of DC current injected into the field winding on the rotor.
