Woodward 2301E, Инструкция по установке и эксплуатации, Страница: 48 / 182

2301E Digital Control Manual 26641
38 Woodward
If the load command discrete input contact is opened (unload) while the breaker
(CB AUX) input contact is closed, the generator will soft unload from the present
load level to the unload trip level. Once the generator load has reached the
unload trip level or the reference has been there for 5 seconds (tunable), the
Open Gen Breaker relay output will open for 1 second (tunable). The load
command discrete input must be maintained OPEN to complete the unload
sequence.
The Load Command discrete input must be maintained logic to
operate the Soft Loading/Unloading sequence. The input must be
OPEN to complete the Unload sequence and disconnect the
generator. The input must be CLOSED to complete the Load
sequence and operate the generator in Isochronous Load Sharing or
Base Load operating mode.
CB AUX
Base
Load Load
Gen
Lower
Spd/Ld
Raise
Spd/Ld
Operation of Load Control
F X X X X Droop
F X X T F Droop lower load
F X X F T Droop raise load
F X X T T Droop remote load ref
T F T X X Isochronous load sharing
T T T X X Base load
T T T F F Base load ref will ramp to
internal base load reference
T T T F T Base load ref will ramp toward
rated load
T T T T F Base load ref will ramp toward
the unload trip level
T T T T T Base load ref will ramp to value
of remote load set point
T X F X X Base load control at the unload
trip level
T X T-F X X Load will ramp to unload trip
level and open gen breaker
Legend: F=False, T=True, X=Don’t Care
Table 3-1. Description of Discrete Inputs While in Load Control
Droop Function
Load control operations are not functional while in droop. The speed reference
must be changed to increase or decrease the generator load while in droop. The
base load and the load discrete inputs have no effect while operating in the droop
mode. The CB Aux contact switches between load control and droop operation.
The droop function supplies a feedback path to bias the speed reference. The
function of droop is to decrease the speed reference as the load increases. This
is done by negatively biasing the output of the speed reference with the droop
function. The CB Aux discrete input contact is used to switch the droop function
on and off. The droop function can be permanently enabled by leaving the CB
Aux contact discrete input false. A complete discussion of droop operation is
included in the Power System Management Concepts section.