AP4 Group – Full-Service Heavy-Duty & Aeroderivative Industrial Gas Turbine Maintenance Provider.

The Excitation system generates variable DC voltage and current to the rotating field to regulate the terminal voltage of the generator within the permissible operating range.

There are two basic excitation systems in operation today: Brushless Excitation Systems, with rotating exciter machines and Automatic Voltage Regulator (AVR), or Static Excitation Systems (SES) feeding rotor directly from thyristor bridges via brushes.The main function of the excitation systems is to provide a variable DC to regulate the terminal voltage to the generator voltage within the permissible operating range of the machine.

Digital Exciters

If you are the owner of a turbine generator set built after 1990 you are most likely operating with the original Digital Excitation System. Depending on the vintage of your digital system the OEM may no longer support your system.

TC&E - A Division of AP4 Group excitation engineers are factory trained to work on several digital excitation systems. Contact us today to further discuss maintenance and testing options and other service solutions available for your digital excitation systems.

Digital Exciters We Support

  • GE EX2000
  • EX2100
  • EX2100e
  • ABB™ Unitrol
  • Hitachi
  • Basler™ DECS series AVR's
  • Brush AVR's

Analog Exciters

Analog Exciters have proven to be very reliable systems, but as these systems continue to age, many utilities are faced with the decision to continue to maintain analog exciters or upgrade them with newer technology. The reuse of the rectifier bridges has become increasingly popular as rectifier bridge technology utilized years ago has exhibited high reliability and proven to remain in excellent operating condition. Hence, replacing only the analog controls due to obsolescence and keeping the power SCR rectifier bridges may be a favorable economic solution for an excitation system upgrade.

Let us help you maintain or upgrade your Analog Exciters!

Our team can provide guidance on these types of decisions and provide the technical field solutions for either maintaining or upgrading your current exciter.

Analog Exciters We Support

  • GE Alterrex
  • GE Generrex
  • GE Bus Fed/Potential Source
  • GE Shunt
  • GE Amplidyne
  • Basler™ SSE
  • EM Regulator