SX440

Automatic Voltage Regulator

• SX440 is a half-wave phase-controlled thyristor type
  Automatic Voltage Regulator (AVR) and forms part of the
  excitation system for a brush-less generator.
• In addition to regulating the generator voltage, the AVR
  circuitry includes under-speed and sensing loss
  protection features. Excitation power is derived directly
  from the generator terminals.
• Positive voltage build up from residual levels is ensured
  by the use of efficient semiconductors in the power
  circuitry of the AVR.
• The AVR is linked with the main stator windings and the
  exciter field windings to provide closed loop control of the
  output voltage with load regulation of +/- 1.0%.
• In addition to being powered from the main stator, the
  AVR also derives a sample voltage from the output
  windings for voltage control purposes. In response to this
  sample voltage, the AVR controls the power fed to the
  exciter field, and hence the main field, to maintain the
  machine output voltage within the specified limits,
  compensating for load, speed, temperature and power
  factor of the generator.
• A frequency measuring circuit continually monitors the
  generator output and provides output under-speed
  protection of the excitation system, by reducing the output
  voltage proportionally with speed below a pre-settable
  threshold. A manual adjustment is provided for factory
  setting of the under frequency roll off point, (UFRO). This
  can easily be changed to 50 or 60 Hz in the field by push-
  on link selection.
• Provision is made for the connection of a remote voltage
  trimmer, allowing the user fine control of the generator’s
  output.
• An analogue input is provided allowing connection to a
  Newage Power Factor controller or other external devices
  with compatible output.
• The AVR has the facility for droop CT connection, to allow
  parallel running with other similarly equipped generators.

• All manufacturer names and numbers are used for reference purpose only and do not imply that any part is the product of these manufacturer.