Woodward 505HT, Инструкция по установке и эксплуатации

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Manual 35116 505HT for Pelton Turbines
Woodward 57
The nozzle load sharing should be thought in terms of water flow
sharing, not actual nozzle demand. Therefore the nozzles x flow
curves should be configured properly to achieve this goal.
Nozzle Rotation
The controller has a series of algorithms to rotate the used nozzles in order to make all nozzles to
open/close even in case the load demand remains low. This can be done on a time basis or triggered if
any nozzle feedback in operation fails (hardware fault or signal fail) or there’s a Major mismatch on the
referred nozzle. A “Rotate Nozzle” command can also be sent voluntarily via discrete input, Modbus or
display command.
When a “Rotate Nozzle” command is issued the nozzle “x” internally becomes nozzle “x+1”. This is done
only in logical terms.
This logic, in association with proper nozzle sequencing configuration, provides a way to balance the time
that each nozzle remains in operation.
If any of the non-selected nozzles has either a signal failure or a major mismatch the rotation command is
inhibited. This logic is also inhibited if the turbine has only one nozzle.
See Appendix F, Figure F-8 for more detail on Nozzle Load Sharing.
Deflector Control
The control provides control for a digital deflector. The deflector is a way to quickly deflect water from the
turbine (in case of a shutdown or load rejection), as a Pelton turbine cannot mechanically close the
nozzles too quickly, due to a phenomenon called “water hammer”.
The deflector can be operated in manual or automatic modes. The manual mode can be enabled/disabled
via discrete input, Modbus command or display. Every time a shutdown occurs the deflector is forced into
automatic mode.
When in manual mode the deflector can be opened or closed voluntarily by discrete input, Modbus
command or display.
When in automatic mode the deflector is commanded to close if any of the following conditions occur:
•
Shutdown
•
Normal stop command and generator breaker opened
•
Road rejection logic is triggered
There are two deflector mismatches: one closed mismatch and one opened mismatch. The closed
mismatch compares the deflector close command with a deflector closed feedback. The opened
mismatch compares the deflector open command with a deflector opened feedback. These mismatches
can be individually configured for either alarm or shutdown. In order to make these mismatches to work
properly one (closed indication) or two (one for closed indication and another for opened indication)
position feedbacks can be used upon configuration.
It’s possible to use continuous or pulse outputs for deflector outputs. If “continuous” configuration is used
the “Close Deflector” output is closed as long as the close deflector command is issued. The “Open
Deflector” output is closed as long as the open deflector command is issued. If “pulse” configuration is
used the “Close Deflector” output is closed for the “pulse time” or until it receives the deflector closed
feedback, whatever comes first. The “Open Deflector” output is closed for the “pulse time” or until it
receives the deflector opened feedback, whatever comes first.
Released