WOODWARD PSG GOVERNORS
Speed droop is the difference between no load rpm
and full load rpm. This difference in rpm divided by the
full load rpm and multiplied by 100 is the percent of
No load speed - Full load speed x 100 =% of speed
Full load speed
The speed droop of the PSG governor can be
adjusted by movement of an adjustment lever on the
outside of the governor that is connected to pivot pin (2)
by link (4). The governor is isochronous when it is
adjusted so that the no load and full load rpm is the
same. Speed droop permits load division between two
or more engines that drive generators connected in
parallel or generators connected to a single shaft.
1. Bracket. 2. Pivot pin. 3. Output shafts.
Speed droop adjustment on PSG governors is made
by movement of pivot pin (2). When the pivot pin is put
in alignment with the output shafts. movement of the
output shaft lever will not change the force of the
speeder spring. When the force of the
speeder spring is kept constant the desired rpm will be
kept constant. See PILOT VALVE OPERATION. When
the pivot pin is moved out of alignment with the output
shafts, movement of the output shaft lever will change
the force of the speeder spring proportional to the load
on the engine. When the force of the speeder spring is
changed the desired rpm of the engine will change.
2. Pivot pin. 4. Link.