Automatic Voltage Regulator AVR for Generator R448 series is a sealed electronic devices, by adjusting the excitation current in order to stabilize the output voltage of the brushless generator.
Generator output voltage is ajusted by using the voltage adjustment potentiometer on the Automatic Voltage Regulator AVR. Cutting excitation current is accomplished by swiching off the supply power to AVR.
When applying a step load to the generator, the rotational speed(frequency) of the genset drops. If the speed is below the preset frequency,the LAM circuits drops the voltage about 25%, as long as the speed has not recovered to normal values.
The LAM is used either to reduce the speed drop of the engine, during the step load, or to increase the applicable step load for the same speed variation so the engine can recover normal speed quickly.
To prevent voltage oscilllations, the frequency threshold must be adjusted about 2HZ below the lowest frequency in normal operation. |