Diane Lindsey CenterPoint Energy SWEDE 2010

Transcription

1 Diane Lindsey CenterPoint Energy SWEDE 2010

2 Agenda Background Pre Hurricane Ike Dredge Evaluation Aftermath of Hurricane Ike in 2008 Temporary West Galveston Mobile Substation Post Hurricane Ike Dredge Evaluation 2010 West Galveston Substation

3 Pelican Island Location

4 Pelican Island Background Temporary 12 kv, 11.8 MVA primary meter service on Pelican Island for dredge 2 phases 150 days/phase Pelican Island Fed from West Galveston (GA 01 and GA 08) Approximately 4 MVA of total load 75 total customers (TAMU and industrial facilities)

5 GA 08 GA 01

6 Dredge Background Remove bottom sediments to expand and maintain channel Move around based on Corps of Engineers bidding process and maintenance schedule High diesel costs discourage deck generators CenterPoint Energy (CNP) experienced historical power quality issues with similar dredge installations

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8 Pre Ike Dredge Evaluation CNP standard evaluation process for new load requests New load on a 12 or 35 kv circuit? How much load is on the circuit? Circuit on the 10% worst circuit list? Need to build feeder main to accommodate new load? Any possible feeder ties? New load behind any protective devices? What is the 2 hr firm for substation transformer?

9 Pre Ike Dredge Evaluation Circuit modifications to isolate circuit and other customers from dredge Isolate dredge to GA 01 as dedicated circuit Move customers from GA 01 to GA 08 Two switching operations to switch load and other customers Line construction at individual locations Construct 2,250 feet of 600 MCM on GA 01 Install kvar cap bank on GA 01

10 Pre Ike Dredge Evaluation Restrictions Install recloser with one shot to lockout Customer signs operating agreement that details maximum load and protection scheme CNP can limit dredge operation in emergency conditions Meet power quality specifications on harmonics and voltage flicker

11 Pre Ike Circuit Modifications

12 Aftermath of Hurricane Ike Remains of restaurant on pier Boat in middle of road near UTMB on Galveston Island

13 Aftermath of Hurricane Ike Water line over 6 high Broken pole on one of the feeds to Pelican Island

14 Aftermath of Hurricane Ike Washed away paved concrete Collapsed beach house

15 Aftermath of Hurricane Ike Collapsed regulator bank Broken transformer pole

16 Aftermath of Hurricane Ike

17 West Galveston Substation Post Ike Water damaged substation relays Water line

18 West Galveston Substation Pre Ike 4 25 MVA substation transformers kv circuits Pelican Island fed from GA 01 and GA 08 Post Ike Initially 1 50 MVA mobile substation 4 circuits each with an 800 A protective relay recloser Added 1 20 MVA mobile substation with 2 circuits to improve reliability Pelican Island fed only from GA 03

19 West Galveston Substation Post Ike Construction of mobile substation in pole yard Poles in yard were washed over 8 chain link fence

20 West Galveston Substation Post Ike Construction of mobile substation in pole yard

21 West Galveston Substation Post Ike 50 MVA mobile substation

22 West Galveston Substation Post Ike Four temporary 800A Reclosers

23 Post Ike Dredge Evaluation Temporary 12 kv, 4.8 MVA primary metered service Original load request 11.8 MVA Circuit modifications to accommodate dredge load Upgrade two existing cap banks Switch load and other customers from GA 03 to adjacent circuits on Galveston Island Upgrade 1,700 feet of conductor from 3/0 to 600 MCM

24 Post Ike Dredge Evaluation Energized in summer phase operation Original request for 150 days each phase Restrictions Install recloser with one shot to lockout Customer signs operating agreement that details maximum load and protection scheme CNP can limit dredge operation in emergency conditions Meet power quality specifications on harmonics and voltage flicker No restrictions on operating months due to low load on island

25 Post Ike Dredge Evaluation Concerns Circuit reliability Voltage flicker Harmonics Power Quality monitor at substation Voltage THD increase 2% with Dredge operation Current THD increase 6% with Dredge operation

26 Dredge Materials Cable reel Silt removal

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28 2010 West Galveston Substation Two 50 MVA substation transformers Transformers, junction boxes, breakers and control house elevated against next tidal surge Reconfigured to 10 original circuits Pelican Island fed from GA 01 and GA 08

29 2010 West Galveston Substation Elevated breakers and bus installation Distribution breaker

30 2010 West Galveston Substation New control house Elevated substation transformer

31 Summary The revised service with a smaller dredge allowed the project to go forward in spite of the system limitations after the hurricane. Ongoing cooperation between the utility and the dredge operator is essential to minimize the impact on other customers.

32 Questions