1 / 21

345 kV High Side Distribution Substation

345 kV High Side Distribution Substation. Jesus A. Guerra, P.E. Distribution System Reliability CenterPoint Energy SWEDE 2011. Agenda. CNP T&D Facts Background of Kuykendahl Substation PTS FailureNew Switching Procedures Addition of Transmission Substation Conclusion Questions.

gali
Télécharger la présentation

345 kV High Side Distribution Substation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 345 kV High Side Distribution Substation Jesus A. Guerra, P.E. Distribution System Reliability CenterPoint Energy SWEDE 2011

  2. Agenda • CNP T&D Facts • Background of Kuykendahl Substation • PTS Failure\New Switching Procedures • Addition of Transmission Substation • Conclusion • Questions

  3. T&D Facts • CNP T&D serves a 5,000-square-mile area that includes Houston, the nation’s fourth largest city. • CNP delivers electricity on behalf of 79 retail electric providers. • 2+ Million Metered Delivery Customers • 27,726 miles of Overhead Distribution Lines • 3,729 miles of Overhead Transmission Lines • 20,080 miles of Underground Distribution Lines • 26 miles of Underground Transmission Lines • 1521 Distribution circuits • 230 Substations (Transmission and Distribution) • 13 Service Centers

  4. CNP Service Area Map

  5. Background • Kuykendahl (KDL) Substation • CNP’s only 345/35 kV Sub • Built in 2001 • 2-60/80/100 MVA Transformers • Initially serving four circuits • (Currently 5 circuits) • Constructed to serve increased load growth that would result in voltage design criteria violations. • Built on existing CNP property

  6. Location

  7. Substation Site (Cow Pasture)

  8. Substation Site

  9. New Feeder Location

  10. New Feeders

  11. PTS Failures • From 7/31/01 – 10/19/01 three PTS failed during attempts to separate a KDL Feeder from Feeders served by other substations (138/35 kV). • Some failed PTS had successful switching operations. (Crews reported excessive arcing) • Due to unique sub design failures resulted in an open transition switching only until further investigated.

  12. PTS Failures • Identified 3 possible causes for PTS failure: • Excessive currents • PTS Rated for 600A and 900A, breaker setting was lower. • Transient Recovery Voltage (TRV) • Difficult to measure in the field. • TRV model was constructed using ATP (Alternative Transient Program). • (Model showed results were slightly higher than the ANSI standard TRV curve) • Switch (Mechanical) Failure • Misalignment, contamination, broken insulators, operator error, etc

  13. PTS Failures • Only the last switch was saved for analysis • Arcing was present. • Manufacturer concluded that interrupters were not properly aligned. • Without the other switches it’s impossible to determine what effect switch failure played in these events.

  14. New Switching Procedure • Load Flow Model simulations revealed large flows of current at the breaker could cause it to trip during routine switching or service restoration. • A new closed transition switching procedure was created. • KDL to KDL switching as 1st option (tie bus at sub) • Other procedures required when rolling the circuit to a particular transformer or adding load to it and performing the operation. • Closed transition would not be possible if one TRF is out of service.

  15. Addition of Transmission Sub • New Transmission Substation • 345/138 kV Sub • Energized 1st Qtr 2010 • Increase capacity for 138 kV lines • 2.5 miles from KDL • Re-evaluation of Switching Procedures

  16. New Transmission Sub

  17. New Transmission Sub 345 Ckt A 345/35 kV Sub 345 Ckt B 138 kV Ckts New 345/138 kV Sub

  18. Re-Evaluation of Switching Procedure • Load Flow study conducted using PSS/E software • L-F studies help determine the steady-state operation on an electrical power system. • 3 models were analyzed to evaluate voltage and current changes at various normally open PTS. • Prior to transmission sub installation • Post installation of transmission sub • Post installation including future load growth

  19. Results • 37 Open PTS studied • Results showed no significant increase in voltage levels prior to and post new transmission sub installation. • Current Changes • 2/3scenarios showed less than 5% change in current levels • 1/3 scenarios showed larger than 5% change: • 8 PTS showed decrease in current up to 33% • 5 PTS showed increase in current (6 – 7%)

  20. Conclusion • The addition of the new transmission sub will allow CNP to continue with the current switching procedures. • As the dynamics of the system changes CNP will have to revisit the switching procedures.

  21. Questions

More Related