Automatic Voltage Regulators. What is a generator AVR or Automatic Voltage Regulator?

All modern ship alternators are equipped with voltage regulators. The regulators permit to obtain constant voltage of generators under various amount of load and power factor. Here we shall speak about AVR for brushless alternators.

Block diagram (Fig. 1) shows the regulator principle in an autonomous alternator system. The alternator voltage is fed to the AVR unit via fuses and exciter switch. The reference level of the alternator voltage is set by the voltage adjusting potentiometer. The difference between the actual voltage and reference value is amplified and converted to triggering pulses to the thyristor bridge. A-c voltage is fed from the alternator via supply transformer to the thyristor bridge.