Pad-Mounted Substation
John Wood
February 23, 2006
IEEE SF Chapter Meeting
1
Electric T&D Engineering Team
zDan Mulkey
zJim Sanborn
zJohn Wood
2
Pad Mounted Substation
zThink Out of the Box.
zBetter Yet. In this Case, Think Into
the Box.
3
12 kV or 21 kV
Source
Pad-Mounted
Substation
Riser Fuse
Single-Line Diagram
1/0 Al 25 kV Cable
Pad-Mounted
Regulator
Pad-Mounted Regulator
By-Pass Switch
2,500 kVA
12 kV or 21 kV to 4 kV
Pad-Mounted Transformer
and Recloser
RECL
1,100 Kcmil Al 25 kV Cable
4 kV Load
4
Forest Substation
5
Regulator By-Pass Switch
6
Regulator
7
Transformer Front View
8
Transformer Back View
9
$$$ Costs $$$
zEstimate for going back with typical
substation design = approximately
$ 750, 000
zActual cost of Forest Substation
Pad-Mounted design =
approximately $ 250,000
10
Division
12 or 21 kV
to 4 kV
Substation
Transformer
Banks
Scheduled for
Replacement
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
12
Savings Over Conventional
Substation
($750,000 – 250,000) X 160 =
$80 Million
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BUT WAIT
THERE IS MORE
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z Aesthetic improvement.
z Much less construction time.
z Takes approximately 1/10 the land
requirement.
z Reliability improvement because birds or
animals can’t short out the substation.
z Ease of Operation.
z Less Maintenance.
15
PG&E Codes
z Pad-Mounted Regulator By-Pass Switch
M262571
z Pad-Mounted Regulator
M262577 – 12 kV
M262565 – 21 kV,
z Pad-Mounted Transformer with Recloser
M262578 – 12 kV 0° phase shift
M261381 – 12 kV 30 ° phase shift
M261381 – 21 kV 0 ° phase shift
M262579 – 21 kV 30 ° phase shift
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The End
Questions???
17