Generator Stator Differential

The 889 provides fault clearing operation at up to sub-cycle speed,

by utilizing a high-speed dual slope differential protection for

detecting and clearing of stator phase faults. Advanced CT saturation

detection algorithms maintain immunity to saturation conditions that

may be caused due to external disturbances. Through the use of

a directional check, additional supervision is provided to ensure

the fault is internal to the generator before triggering it to trip. This

sub-cycle operation translates to less burning, and hence low carbon

dissipation and thermal stress on insulation. This also enables root

cause analysis during diagnosis/maintenance of the winding (sever

longer duration faults burns-out all the evidence and make root

cause analysis extremely difficult or sometimes impossible).