TM 9-6115-604-34
NAVFAC P-8-633-34
TRACE AND DEFINITIONS APPLY TO EITHER VOLTAGE OR FREQUENCY
NOTE
CHART MARKED AT START OF TEST
A
ACTUAL INSTRUMENT TRACE OF FUNCTION.
H
POINT AT WHICH TRACE ENTERS AND
B
OBSERVED STEADY-STATE BAND (TWO LINES
REMAINS
WITHIN
PRESCRIBED
LOAD
BAND.
PARALLEL TO THE AXIS OF CHART MOVEMENT,
R
REGULATION BETWEEN ANY TWO LOADS.
ONE EACH PASSING THROUGH THE CENTER
OF POINTS OF MAXIMUM AND MINIMUM
S
SURGE AFTER A LOAD CHANGE.
TRACE EXCURSION RESPECTIVELY DURING
THE SHORT-TERM STABILITY SAMPLE
SO
OVERSHOOT
PERIOD, Ts.)
SU
UNDERSHOOT
C
MEAN OF OBSERVED BAND.
TFL
OBSERVED RECOVERY TIME, NO LOAD
CL
MEAN VALUE AT SELECTED LOAD.
TO DATE.
CN
MEAN VALUE AT NO LOAD.
TFN
OBSERVED RECOVERY TIME, LOAD TO NO
LOAD.
D
PRESCRIBED STEADY-STATE BAND.
TG
MAXIMUM ALLOWABLE RECOVERY TIME.
E
POINT AT WHICH TRACE INITIALLY LEAVES
PRESCRIBED LOA D BAND UNDER CONDITION
TGL
MAXIMUM ALLOWABLE RECOVERY TIME,
OF DECREASE IN LOAD.
NO LOAD TO NO LOAD.
F
POINT AT WHICH TRACE ENTERS AND REMAINS
TGN
MAXIMUM ALLOWABLE RECOVERY TIME,
WITHIN PRESCRIBED NO LOAD BAND.
LOAD TO NO LOAD.
G
POINT AT WHICH TRACE INITIALLY LEAVES
Ts
PRESCRIBED SHORT-TERM SAMPLE TIME
PRESCRIBED NO LOAD BAND.
FOR DETERMINING STABILITY.
Figure 12-9. Overshoot and Undershoot Chart Recording
12-32
