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Pad-Mounted Substation

John WoodFebruary 23, 2006IEEE SF Chapter Meeting

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Electric T&D Engineering Team

Dan Mulkey

Jim Sanborn

John Wood

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Pad Mounted Substation

Think Out of the Box.

Better Yet. In this Case, Think Into the Box.

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12 kV or 21 kVSource

RECL

4 kV Load

1,100 Kcmil Al 25 kV Cable

2,500 kVA

12 kV or 21 kV to 4 kV

Pad-Mounted Transformerand Recloser

Pad-Mounted RegulatorBy-Pass Switch

Pad-MountedRegulator

Riser Fuse

1/0 Al 25 kV Cable

Pad-Mounted Substation

Single-Line Diagram

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Forest Substation

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Regulator By-Pass Switch

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Regulator

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Transformer Front View

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Transformer Back View

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$$$ Costs $$$

Estimate for going back with typical substation design = approximately $ 750, 000

Actual cost of Forest Substation Pad-Mounted design = approximately $ 250,000

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12 or 21 kV to 4 kV

Substation Transformer Banks

Scheduled for Replacement

Division Number of Transformer

Banks

Central Coast 30

Diablo 16

East Bay 37

Mission 13

North Bay 6

North Coast 2

North Valley 2

Peninsula 7

San Francisco 45

San Jose 2

Total 160

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Do The Math

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Savings Over Conventional Substation

($750,000 – 250,000) X 160 =

$80 Million

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BUT WAITTHERE IS MORE

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Aesthetic improvement.

Much less construction time.

Takes approximately 1/10 the land requirement.

Reliability improvement because birds or animals can’t short out the substation.

Ease of Operation.

Less Maintenance.

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PG&E Codes

Pad-Mounted Regulator By-Pass Switch M262571

Pad-Mounted RegulatorM262577 – 12 kV M262565 – 21 kV,

Pad-Mounted Transformer with Recloser M262578 – 12 kV 0° phase shiftM261381 – 12 kV 30 ° phase shiftM261381 – 21 kV 0 ° phase shiftM262579 – 21 kV 30 ° phase shift

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The End

Questions???