Woodward 2301E, Инструкция по установке и эксплуатации, Страница: 108 / 182

2301E Digital Control Manual 26641
98 Woodward
5. Set the Gain B Breakpoint at the point slightly above the first inflection point
in the load plot. Gain B should now be adjusted to obtain good control at the
inflection point B. Note: you may already have obtained the correct value in
Step 1c.
Be prepared to change the dynamics settings since the actuator
bump transient may stimulate instability, which could result in an
overspeed condition.
BUMP ENABLE must be set to TRUE to enable the BUMP ACT
function. See the ACTUATOR BUMP menu.
L**FUEL LIMITERS 1/2**
Fuel limiters restrain the fuel demand from the control to the actuator.
01 START FUEL LIMIT (%FD) dflt = 100.00 (15.00
–110.00)
This limits the percent fuel demand when the engine is started. The limit is
usually set at the fuel level required to start the engine. The limiter is disabled
when the engine fuel is controlled by speed (see Figure 4-9). The limiter begins
out of the way at 100% with no speed. Upon speed exceeding the failed speed
sense percent, the START FUEL LIMIT immediately limits the fuel to the start
fuel limit level. The limiter then ramps at START RAMP RATE (%FD/S) until the
speed has reached 95% of reference and the Speed Control PID is in control for
1 second.
Figure 4-9. Start Limit Function
02 START RAMP RATE (%FD/S) dflt = 10.00 (1.00
–180.00)
Establishes the start limiter ramping rate at which the fuel demand increases to
assist starting in colder ambient conditions.