Woodward 2301E, Инструкция по установке и эксплуатации, Страница: 44 / 182

2301E Digital Control Manual 26641
34 Woodward
contact is closed, and Remote Reference input is selected as Speed
Reference setting or as Baseload reference setting.
Speed Reference and Ramp Functions
This section describes the operation of the speed reference and ramp functions
and their relation to each other. Read this section carefully to be sure your
sequencing provides the proper operating modes.
The control provides start, idle, lower limit, raise limit, and rated set points, accel
and decel times, and raise and lower rates, for local operation. Accel time
determines the time required for the engine to ramp from start to idle speed and
from idle to rated speed. Decel time determines the time required for the engine
to ramp from rated speed to idle speed. Raise and lower rates determine how
fast speed is increased or decreased by raise and lower discrete input
commands.
The Start Speed can be enabled for applications which require this function (e.g.,
spark gas reciprocating engines).The start speed set point provides a speed
reference above cranking speed but below the speed achieved with the start fuel
limit setting (light-off speed). This function is configurable. The default has this
function disabled. When configured TRUE, the start reference is selected by
control power-up, engine not running, or engine cranking. The Start reference is
the speed reference until the engine starts. After the engine speed exceeds the
start speed set point the speed will accelerate by a controlled ramp to the
reference selected by the Idle/Rated contact input. This may not be the desired
mode of operation, so be sure to understand the implications of operating the
control in this manner.
The idle speed set point is provided for engine warm-up or cool-down cycles. Idle
speed may be set equal to or less than the rated speed set point. Idle is
independent of the lower limit set point and may be set at a lower speed. The idle
speed set point is selected when the Rated contact is open, if the start reference
is removed either by configuration or engine speed above start speed. Closing
the Rated contact ramps the speed set point from idle to rated, if the start
reference is removed.
Closing either the raise or lower contacts while ramping from idle to rated results
in immediate cancellation of the idle to rated ramp, and the ramp will stop at that
point. After acceleration to rated speed is completed, the raise and lower
commands increase and decrease engine speed based on the raise and lower
rate settings. The raise and lower commands will not increase the speed
reference above the raise limit or below the lower limit. The raise and lower
commands can be used as speed trim inputs for manual synchronization. Or if
the system uses droop operation for paralleling, the raise and lower inputs will be
load setting inputs.
If remote speed setting operation is configured and enabled after the engine
reaches rated speed, the control will ramp speed to the reference value set by
the Remote Reference input at the Remote Reference increase or decrease time
settings. The Remote Reference range is selectable and can be configured for
one of two operating ranges: from 4 to 20 mA or 1 to 5 V. The minimum input
value (4 mA or 1 V) Remote Reference set point may be set to a lower or higher
speed than the high input (20 mA or 5 V) set point, providing for either direct or
reverse-acting remote speed setting.
If the Remote Speed Reference input is configured and enabled when the
Idle/Rated contact is closed or during the idle to rated ramp, the speed reference