Woodward 2301E-HT, Руководство по эксплуатации продукта

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Manual 35092 2301E-HT Hydro (Francis Turbines)
Woodward 18
External Start Permissive
An external start permissive is available when one of the configurable inputs is configured to do it. When
the unit is started up and the control resets, the start permissive contact must be closed before the unit
issues a governor run command.
Speed Signal Processing
The 2301E-HT for Francis turbines has two speed signal inputs. The 2301E-HT accepts any sine wave or
square wave provided by a speed sensor that is proportional to the speed of the turbine. This can come
from magnetic pickups.
The 2301E-HT control must be configured according to the type of speed signal being provided, the rated
speed (rpm) of the turbine, the number of gear teeth (if applicable), and the system frequency (60 Hz, 50
Hz, etc.). The 2301E-HT then converts the speed signal frequency into percent of rated speed. All speed
values during the configuration and operation of the control are in terms of percent of rated speed unless
stated otherwise.
The 2301E-HT monitors speed signal failures and overspeed. When the turbine is stopped or moving
very slowly, the control will not have a valid speed signal, but the control should not see this as a speed
signal failure. When the turbine is started, the speed signal is i
gnored by the control until the “Time to
Start Speed” expires. When the turbine is stopped, the speed signal is ignored once the speed drops
below 50% and the gates are closed.
The 2301E-HT has an electronic overspeed detection, which issues a shutdown to the control. The
“Overspeed” value configured in the control is in percent of rated speed. The overspeed detection is also
ignored at the same time the speed signal failure is ignored, as mentioned above. In addition, it is delayed
by one second in order to avoid nuisance trips due to electrical noise on the speed signal. When the
control is in Maintenance Mode, all speed signals, speed signal failures, and overspeeds are ignored.
An overspeed test feature is available so that the mechanical overspeed (or independent secondary
overspeed) trip can be easily tested. To enable the overspeed test, set “Mech Overspd Test” to true
under the service menu. The test enable switch is hooked up to a 30-minute timer so that the test is not
accidentally left enabled. When the overspeed test is enabled, the electronic overspeed trip is disabled,
the isochronous speed reference ceiling is raised to 200%, and the raise/lower rate on the isochronous
speed reference is increased to 10% per second. To perform the overspeed test, the test must be
enabled and the turbine must be running off-line. The speed reference must be raised until the turbine
trips from the mechanical overspeed. The mechanical overspeed should be wired in series with the ESD
input string so that an ESD is issued to the control.
The 2301E-HT has a speed deadband function that can be enabled. The speed deadband function is a
configurable window around rated speed within which the 2301E-HT will not respond to speed changes.
The deadband window has configurable set points above and below rated speed. In the example below,
the high set point is 100.05% rated speed (60.03 Hz on a 60 Hz system), and the low set point is 99.97%
rated speed (59.98 Hz on a 60 Hz system). When the unit’s speed fluctuates around rated speed the
control will not respond unless the speed gets outside the configurable window.
Figure 3-4. Speed Deadband Function
Released