Automated Voltage Regulator (AVR)
Siemens invented the Voltage Regulator in 1932 and pioneered its use in the USA. Voltage Regulators are used to ensure that a desired level of voltage is maintained at all times. A Voltage Regulator comprises a tapped autotransformer and a tap changer. Rated voltage – single phase: 2.5 to 19.9 kV
Rated voltage – three phase: 13.2 to 34.5 kV
Advantages / characteristics:
Voltage regulators are oil-immersed and can be 1-phase or 3-phase. They may be self-cooled or forced-air-cooled and they can be used in any electrical system to improve voltage quality.