ALH

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Author:
canadashea
ID:
183183
Filename:
ALH
Updated:
2012-11-21 23:20:59
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ALH
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ALH
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  1. What is the only mode that ALH units should be operated in?
    ALH units must always be operated in Flow Mode.
  2. Which operating order describes the system for responding to unscheduled changes in discharge at the Arrow Lakes Generating Station (ALH) including discharge adjustments at the Hugh Keenleyside Dam (HLK) to substantially restore the Facility Discharge Requirement?
    The Local Operating Order (LOO) SE3.
  3. Describe the 60 Second Timer
    The 60 Second Acknowledge Setpoint Timer: After adjusting a unit flow setpoint, remote operators have 60 seconds to click Initiate or the change will revert to the previous number and nothing will happen.
  4. Describe the 2 Minute Timer
    The 2 Minute Synchronization Timer: After unit start is initiated, ALH units must remain in SNL for 2 minutes before they can be synchronized.
  5. Describe the 5 Minute Timer
    The 5 Minute Loading Timer: Once a unit is synched to the system the operator must enter a flow setpoint within 5 minutes or else risk having to wait 24 minutes for the channel stability timer to reset.
  6. Describe the 10 Minute Timer
    The 10 Minute Timer Flow Restoration Timer: Plant Operators have 10 minutes from the time a unit trips to re-establish flow by whatever means is appropriate for the particular circumstance (unit re-sync or HLK gate movement).
  7. Describe the 24 Minute Timer
    The 24 Minute Channel Stability Timer: The Channel Stability timer will limit remote operators to one unit start or flow increase per 24 minutes. Unit stop and flow decrease is always possible. Studies conducted have found that adjustments to unit discharge when the forebay level is below 433m can cause excessive disturbance in the approach channel and that the water will settle sufficiently after 24 minutes.
  8. Describe the 5 timers associated with ALH.
    • • The 60 Second Acknowledge Setpoint Timer: After adjusting a unit flow setpoint, remote operators have 60 seconds to click Initiate or the change will revert to the previous number and nothing will happen.
    • • The 2 Minute Synchronization Timer: After unit start is initiated, ALH units must remain in SNL for 2 minutes before they can be synchronized.
    • • The 5 Minute Loading Timer: Once a unit is synched to the system the operator must enter a flow setpoint within 5 minutes or else risk having to wait 24 minutes for the channel stability timer to reset. This would only be of concern if the forebay was below 433m since there would no 24 minute restriction if it was above 433m.
    • • The 10 Minute Timer Flow Restoration Timer: Plant Operators have 10 minutes from the time a unit trips to re-establish flow by whatever means is appropriate for the particular circumstance (unit re-sync or HLK gate movement).
    • • The 24 Minute Channel Stability Timer: When the forebay is below 433m the Channel Stability timer will limit remote operators to one unit start or flow increase per 24 minutes. Unit stop and flow decrease is always possible. Studies conducted have found that adjustments to unit discharge when the forebay level is below 433m can cause excessive turbulence in the approach channel and that the water will settle sufficiently after 24 minutes.
  9. What actions are inhibited while the 24 Minute Channel Stability Timer is active? Which actions are still available? How can operators know that the timer is active?
    • Only one of either a unit start or flow setpoint increase will be allowed while the 24 minute timer is active; however, unit stop and flow setpoint decreases are always possible.
    • Remotely, the timer is indicated by “Ramp in Progress” on the remote ALH SCADA unit screen. Locally the timer is shown on the Unit Control screen.
  10. What are the consequences of unit restart delays that are longer than 10 minutes?
    Restart delays greater than 10 minutes may result in environmental emergencies due to fish stranding in the reduced water levels in the Columbia River down stream of HLK.
  11. Who should be contacted first if operator attention is required at ALH? If they cannot be contacted for whatever reason, who should be contacted instead?
    The ALH Control Room should be attempted first, followed by FortisBC. Fortis is responsible for ALH operator callout.
  12. What are the key operating orders for Plant Operators regarding ALH?
    • SE3
    • A07
    • 4T-ALH-01
  13. When is HLK normally staffed? In what situation should they be contacted?
    • 0600 - 1600 during weekdays.
    • 0800 - 1600 during weekends and statutory holidays.
    • If an unrecoverable trip happens during normal staff hours, HLK lock-keepers should be contacted immediately to restore flows by operating the HLK gates.
    • If an unrecoverable trip happens outside of normal staff hours, RGO should be initiated immediately and lock-keepers contacted secondarily.
    • Lock-keepers should be informed anytime RGO is used.
  14. What is the main priority for a Plant Operator should there be a trip at ALH?
    Restore water flow within 10 minutes. First attempt a unit re-synch (check with Grid 1 to make sure the line is energized). If unit(s) are unrecoverable, either call the lockkeeper or initiate RGO (depending on the day and time).
  15. Before attempting to re-synch a unit or units after a trip, who else in the control room should be consulted?
    Grid 1. Make sure that it is okay to close the unit breakers.
  16. Name all the entities involved with ALH. ie: Who owns what and who is responsible for what?
    • • Arrow Lakes Hydro generating station is owned by Arrow Lakes Power Corporation (ALPC), an IPP.
    • • Adjacent to the station, the Hugh Keenleyside Dam is owned by BC Hydro and operated by BC Hydro lock-keepers.
    • • Energy is fed into the FortisBC system at 230kV via the ALPC owned 2L290. Operating authority and responsibility for 2L290 are assigned to FortisBC.
    • • FortisBC dispatches ALH operators and electricians.
  17. If the forebay level is below 433m and unit(s) 1 and/or 2 trip to speed-no-load, should the Plant Operator attempt to re-sync?
    No. Leave the unit(s) in SNL. Anytime there is a trip with the forebay below 433m, flows should be restored by other means than re-synchronization since the channel stability timer (24 minutes) will be in effect. Depending on the day and time, call the lock-keeper or initiate RGO. In either case, inform Fortis of the occurrence once corrective action has been initiated.
  18. If one or two units trip to SNL with the forebay below 433m either the lock-keeper must be called or RGO intitiated within 10 minutes. Operators should not attempt to re-synchronize units because of the 24 minute channel stability timer limitation. Should the unit(s) be shutdown or left in SNL?
    The unit(s) should be left in SNL until the ALH operator can attempt a re-sync. If units are left in SNL for more than an hour they will automatically shut down.
  19. If the forebay level is above 433m and unit(s) 1 and/or 2 trip to speed-no-load, should the Plant Operator attempt to re-sync?
    Yes. If it is possible to re-sync the units, check that the line 2L290 is ready and bring the units back one at a time. This means that if 2 units have tripped to SNL, synchronize one unit and bring it up to pre-disturbance flow then do the same with the other unit. Inform Fortis of the occurrence once corrective action has been initiated.
  20. What is Gross Trip?
    A comparison of the canal forebay elevation / turbulence compared to scroll-case pressure is done and may cause a unit trip. This is called Gross Trip which is headloss protection that will result in an 86N.
  21. Does ALH have black start capability? If so, is it remote or local?
    ALH does not have black start capability.

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