In EasyPower, the "Field Forcing" designation refers to how the generator’s exciter is powered.
Where the exciter is powered in such a way that it continues to supply armature field current for an extended period after a fault, it should be designated as “With Field Forcing.”
The link below references a white paper from Cummins Power Generation and describes four methods to power the exciter system in the generator:
- Self-Excited (Shunt)
- Excitation Boost System (EBS)
- Permanent Magnet Generator (PMG)
- Auxiliary Winding (AUX)
The only one that would not be considered as “With Field Forcing” is the Self-Excited (Shunt) system.