Excitation system for excitation of synchronous machines


Our new generation of excitation systems offers the user configurable control structures following IEEE 421.5.

This allows brushless, static and compounded excitation devices to be implemented for synchronous machines in regenerative and motor operation on the mains or converter, at mains frequencies from 16.7 to 400 Hz.The XD3S excitation system is intended for operation on synchronous machines with medium to high excitation current or auxiliary excitation current requirements. The basic system consists of an SC1200 control unit and one or more gate units.

Several remote GU3006 thyristor gate units can be operated for parallel thyristor bridge operation or to implement various redundancy scenarios.




Operating voltage: 24 V DC ±20 % 

Control deviation: 0,25 %

Suitable for:  Synchronous machines

Synchronization voltage: 3 x 800 V AC

Early network detection from: 8 V






Parameterization is performed via the powerful EM3000 Engineering Manager, which is available as PC application software and is connected to the controller via the Ethernet service interface.



Operating modes

Voltage control (PID)

Excitation current control (PID)

Uf-controller / open loop operation

Bumpless switching between all operating modes

Reactive power statics

Active power stabilization

Operating modes and setpoints controllable via galvanic inputs or Modbus

Power factor correction (PID) at machine or grid transfer point




Limiters and additional functions


Armature current limitation for mains and short-circuit operation (AMZ with maximum current stage)


Reactive power statics, reactive current compensation control for parallel synchronous machines

Under-excitation limitation, definition via straight line segments

Excitation current limitation (AMZ with maximum current stage)

Active power stabilization PSS2A, B, C

Excitation control, overshoot-free (soft start)

Static voltage maintenance / reactive power provision according to VDE-AR-N 4110 / 4120:2018-11 (section 10.2.2)

V/f reduction

Setpoint synchronization for redundant systems

 Grid synchronization



Machine monitoring and control

Stator voltage monitoring UMZ, 3-stage

Diode fault detection in brushless operation


Stator current monitoring UMZ, 3-stage

Thyristor bridge monitoring:

  • Current amount
  • Unbalanced load
  • Temperature
  • Fuse monitoring
  • Fan monitoring