The HOT blade

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					         3D Cam Controllers
BACKGROUND:
 Mechanical Governors
  – Original equipment installed 1950s (McN) -
    1980s (B2)
  – Blade position follows gate position
      Based on shape of hard cam (cam plate)
      Hard cam valid only for single head
      Blade position dependent on gate position
                 Mechanical Governor
            Cam Follower          Lever




                                            Connecting
                                            Rod
Cam Plate




                           Gate Restoring
                                Shaft
                 3D Cam Controllers
Add-on retrofitted to existing Mechanical Governors
 – Originally installed late „80s - early 90‟s. Newer version
   installed 2001 to ~2006 (NWW).
 – Stepper Motor used to rotate cam plate & “fine tune” blade
   position
 – Provides limited range of blade positioning independent of
   gate
                                               Steep
                                               blade
         Flat
         blade                        Gates
                                      open

                  Gates
                  closed




                                     Stepper
                                      motor
      3D Cam Controllers
Cam Follower



                       Cam Plate




                                   Gate Restoring
                                   Shaft
                  Stepper Motor
         3D Cam Controllers
Target Blade position a “look-up” value from Cam
Table
– Based head & gate position
– Cam Table covers all operating heads
– Cam Table developed from Index Testing
Index Testing one unit of every family (Lower
Columbia & Lower Snake) to develop:
– Cam table (optimum gate - blade relationships)
– 1 % Operating limits
– Discharge Tables
Testing begun in FY00, completed FY06.
Latest tables installed at all projects & GDACS
       3D Cam Controllers
As of 2006
– New versions of 3D cam controllers in-place (NWW)
– Updated Tables in-place (all Projects)
Are 3D cams functioning as intended?
– Operational Surveys conducted annually (beginning
  in ‟05)
    “Snapshot” surveys
    Limited number of issues identified
– Expanded Surveys conducted Fall ‟07 & Mar „08
    Archived GDACS data used to better evaluate 3D cam
    operation
    Indentified frequency that 3D Cam Controllers were non-
    functional (unit by unit evaluation)
    3D Cam Controller Survey Results
LMN and LWG:
– 3D cam controller functioning as intended
  vast majority of time (+/- 0.5 deg blade
  positioning error)
           Lower Monumental           Lower Granite
           Sept '07  Mar '08       Sept '07   Mar '08
  Unit 1     n/a       n/a          98.9%     94.8%
  Unit 2    62.5%     99.5%          OOS       OOS
  Unit 3    99.7%     99.5%        100.0%     92.0%
  Unit 4   100.0%     98.9%        100.0%     98.8%
  Unit 5    99.7%     99.8%         97.3%     99.1%
  Unit 6   100.0%    100.0%        100.0%     97.3%

NOTE: LMN U2 low percentages Sept 07 due to stepper motor
  assembly binding (assembly since replaced)
                               3D Cam Controller Survey Results
                        Lower Monumental Unit 2 3D Cam Operation
                     34   Based on GDACS Hourly Logged Data                                                                         2
                                  7 Dec 07 - 7 Mar 08                                              105' NS
                                                                                                                                    1.5
                                                                                                 cam curve
                     32                                                                                                             1
                                                                                                                                    0.5
                     30                                                                                                             0




                                                                                                                                           Blade Positioning Error (deg)..
                                                                                                                                    -0.5
Blade Angle (deg).




                     28                                                                                                             -1
                                                                                                             95' NS
                                 Measured Blade Angle                                                        cam curve              -1.5
                                 Ideal Blade Angle
                     26                                                                                                             -2
                                 Blade Positioning Error
                                                                                                                                    -2.5
                     24                                                                                                             -3

                                                                                Results:
                                                                                                                                    -3.5
                                                                                1905 GDACS Logged Hrs of Operation
                     22                                                                                                             -4
                                                                                99.5% of time blade error within +/- 0.5 deg        -4.5
                                                                                      (deadband = 0.5 deg)
                     20                                                                                                             -5
                                                                                                                                    -5.5
                     18                                                                                                             -6
                          50        55               60       65            70             75                 80               85
                                                           Wicket Gate Angle (deg)
                      4               Estimated Loss in Efficiency
                                     Due to Blade Positioning Error

                     3.5


                      3
Loss in Efficiency




                     2.5


                      2


                     1.5


                      1


                     0.5


                      0
                           0   0.5           1                1.5         2   2.5
                                      Blade Positioning Error (degrees)
   3D Cam Controller Survey Results
McN:                          Aug '08             Mar '08 (prelim)
– Varied             +/- 0.5 deg +/- 1.0 deg +/- 0.5 deg +/- 1.0 deg
            Unit 1       99%         100%        86%          99%
results     Unit 2       41%          99%        92%          96%
            Unit 3       51%         100%        82%          99%
            Unit 4       89%          93%        82%          94%
            Unit 5       60%          98%        93%          97%
            Unit 6       60%          94%        89%          98%
            Unit 7       60%          99%        75%          88%
            Unit 8       51%         100%        93%          99%
            Unit 9       93%          95%        83%          90%
           Unit 10       51%         100%        86%          96%
           Unit 11       40%          70%        93%          99%
           Unit 12       41%          66%        92%          98%
           Unit 13       30%          60%        75%          98%
           Unit 14       35%          60%        86%          94%
    3D Cam Controller Survey Results
McN Aug 08 Surveys identified 3 areas affecting
3D cam operation:
 – Excessive deadbands on Units 2,3, 5-8, 10-14
 – Faulty head indication to Units 11-14
 – Binding of string mechanisms causing blade
   transducer faults
                                  3D Cam Controller Survey Results
    McN: Excessive deadband (+/- 1 deg)
                                                         McNary Unit 2
                        27                 3D Cam Operation from 3/28/2007 to 7/17/2007                             2.5

                        26                                                                                          2

                        25                                                                                          1.5




                                                                                                                           Blade Positioning Error (degrees)
                        24                        75' cam ESBS curve                                                1
Blade Angle (degrees)




                        23                                                                                          0.5

                        22                                                                                          0

                        21                                                                                          -0.5

                        20                         70' cam ESBS curve         1335 recorded hrs of operation        -1

                        19                                                    Within +/- 1 deg: 99% of time         -1.5
                                              Measured Blade Angle
                        18                                                                                          -2
                                              Ideal Blade Angle
                        17                    Blade Positioning Error                                               -2.5

                        16                                                                                          -3
                             45       50              55                60                 65                  70
                                                      Wicket Gate Angle (%)
                                  3D Cam Controller Survey Results
McN: Deadband reduced (+/- 0.5 deg)
                        35
                                                       McNary Unit 2                                              4
                                         3D Cam Operation from 12/28/2007 to 3/3/2008
                        33                                                                                        3


                        31                                                                                        2


                        29                                                                                        1
Blade Angle (degrees)




                                                                                                                       Blade Error (degrees)
                        27                                                                                        0


                        25                                                                                        -1


                        23                                                                                        -2


                        21                                                            Measured Blade Angle        -3
                                                                                      Ideal Blade Angle
                        19                                                            Blade Error                 -4
                                                 1550 hrs of operation

                        17                       Within +/- 0.5: 91.9% of time                                    -5
                                                 Within +/- 0.7: 95% of time

                        15                                                                                        -6
                             40     45    50         55            60            65     70           75      80
                                                       Wicket Gate Opening (%)
                              3D Cam Controller Survey Results
McN: Faulty head indication Units 11-14
                         27                    McNary Unit 12                                                      2.5
                                  3D Cam Operation from 3/28/2007 to 7/17/2007
                         26                                                                                        2
                                                                           75' ESBS cam curve


                         25                                                                                        1.5
                                                                                                       70' ESBS
                                                                                                       cam curve
                         24                                                                                        1




                                                                                                                          Blade Positioning Error (degrees)
 Blade Angle (degrees)




                         23                                                                                        0.5


                         22                                                                                        0


                         21                                                                                        -0.5


                         20                                                                                        -1
                                                                     Measured Blade Angle
                                                                     3D Cam Ideal Blade Angle
                         19                                          CALCULATED Ideal Blade Angle                  -1.5
                                                                     CALCULATED Blade Positioning Error
                         18                                                                                        -2


                         17                                                                                        -2.5


                         16                                                                                        -3
                           45.0   50.0          55.0           60.0              65.0           70.0           75.0
                                                       Wicket Gate Angle (%)
                                3D Cam Controller Survey Results
McN: Failed pressure x-ducer replaced by Project personnel
                                                                           McNary Unit 11
                        35                                      3D Cam Operation from 12/20/07 to 3/3/08                          2.5


                        33                                                                                                        2
                                   1615 Recorded Hrs of Operation

                                   Within +/- 0.5 : 92.44% of time
                        31                                                                                                        1.5
                                   Within +/- 0.6 : 95% of time


                        29                                                                                                        1
Blade Angle (degrees)




                                                                                                                                         Blade Error (degrees)
                        27                                                                                                        0.5


                        25                                                                                                        0


                        23                                                                                                        -0.5


                        21                                                                                                        -1


                        19                                                                                                        -1.5
                                                                                                 Measured Blade Angle
                        17                                                                       Ideal Blade Angle                -2
                                                                                                 Blade Error

                        15                                                                                                        -2.5
                         40.0     45.0          50.0            55.0          60.0        65.0           70.0           75.0   80.0
                                                                     Wicket Gate Opening (%)
             3D Cam Controller Survey Results
  McN: Design for OH transducer mounting modification sent to
  Project 21 Feb

           Pointer &
              Scale




       String              Rotating
                           Shaft
  Mechanism


Existing
Encoder
                           3D Cam Controller Survey Results
LGO Sept 07 Survey: Limited data available.
                         Extended operation without 3D cam functional – operation on
                         hard cam
                          33                 Little Goose Unit 1
                          32        Gate/Blade Settings During Operation

                          31                                               100' cam curve
                                                                                                                       95' cam curve
                          30
                          29
                          28
 Blade Angle (degrees)




                          27
                                                                                                        Measured Blade Angle on ''Hard
                          26                                                                            Cam''
                          25                                                                            Ideal cam curve (AVG Head of 97.6')

                          24
                                                                                        1 deg - 2 1/2 deg error in blade angle
                          23                                                            (depending on operating point)
                          22
                          21
                                                                                 NOTES:
                          20                                  "Take-Off"         For Unit 1: 243 hours of operation recorded (plotted here)
                                                              Point              For Unit 2: 51 hours operation recorded
                          19                                                     For Unit 3: 0 hours of operation recorded
                          18         Flat on-cam
                                     blade angle = 18.8 deg
                          17
                               50         55           60           65            70            75           80           85           90
                                                                     Wicket Gate Angle (%)
   3D Cam Controller Survey Results
LGO:
– GMT travelled to site 17 Dec 3D cam
  programming restored.

                     Mar '08
                   +/- 0.5 deg
          Unit 1       62%
          Unit 2       89%
          Unit 3       82%
          Unit 4       96%
          Unit 5       97%
          Unit 6      OOS
                           3D Cam Controller Survey Results
LGO Mar 08 Survey:
                               Little Goose Unit 2 3D Cam Operation
                     35                                                                                                          2
                               Based on GDACS Hourly Logged Data
                                        18 Dec 07 - 28 Feb 08                                                                    1.5
                     33                                                                                                          1
                                                                                                                                 0.5
                     31                                                                                                          0




                                                                                                                                        Blade Positioning Error (deg).
                                                                                                                                 -0.5
Blade Angle (deg).




                     29                                                                                                          -1
                                       Measured Blade Angle
                                       Ideal Blade Angle                                                                         -1.5
                                       Blade Error
                     27                                                                                                          -2
                                                                                                                                 -2.5
                     25                100' NS                                                                                   -3
                                       cam curve
                                                                             Results:                                            -3.5
                                                                             498 GDACS Logged Hrs of Operation
                     23                                                                                                          -4
                                                                             89.3% of time blade error within +/- 0.5 deg
                                                                                   (deadband = 0.5 deg)                          -4.5
                     21                              95' NS                  96.4% of time blade error within -0.7 to            -5
                                                     cam curve                       + 0.5 deg
                                                                                                                                 -5.5
                     19                                                                                                          -6
                          55            60             65               70                   75                 80          85
                                                              Wicket Gate Angle (deg)
      3D Cam Controller Survey Results
IH:
– Dec ‟07 Survey indicated frequent faults.
– Project has been troubleshooting. Potential
  hardware modifications implemented.
                       Mar '08
                     +/- 0.5 deg
            Unit 1       90%
            Unit 2        n/a
            Unit 3        n/a
            Unit 4       93%
            Unit 5       77%
            Unit 6      OOS
           3D Cam controllers
NWW Surveys to be repeated mid-
summer
What about NWP?
– 3D cams info not logged into GDACS
– Cannot perform similar evaluation of
  operation
– Annual surveys limited to “snap shot”
– Surveys have not identified any significant
  issues
          3D Cam Controllers
Considerable Improvement from Fall ‟07

Continue to work on improving reliability

Continue surveys to ensure we don‟t veer
off track

				
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posted:4/5/2011
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