IEEE Rural Electric Protection Conference 2011

1. IEEE Rural Electric Protection Conference 2011 High-Speed Communication-Assisted Tripping and Sectionalizingfor Distribution Systems Steve Turner Senior Applications Engineer Beckwith Electric Company, Inc.

2. High-Speed Communication-Assisted Tripping & Sectionalizing Introduction • How to apply communication-assisted tripping and sectionalizing • Special considerations for distribution systems (e.g., feeder with distributed generation) • Several detailed examples • Specific settings and operational details of these schemes Intended for - Rural electric distribution systems that can operate in a network

3. High-Speed Communication-Assisted Tripping & Sectionalizing The Smart Grid era has ushered in a new age revitalizing our distribution assets Utilizedigitaltechnology (high-speed communication) at the enterprise level

4. High-Speed Communication-Assisted Tripping & Sectionalizing HSCAT, High-Speed Communication-Assisted Tripping NO NC Where: R1 Recloser #1 R2 Recloser #2 L1 Feeder Relay #1 L2 Feeder Relay #2 D1 Sectionalizer #1 (motor operated - no remote control) D2 Sectionalizer #2 (motor operated - no remote control)

5. High-Speed Communication-Assisted Tripping & Sectionalizing HSCAT Scheme Logic Permissive Overreaching Transfer Trip (POTT) • High-speed tripping eliminates the need for coordination between the reclosers with their perspective sectionalizers following the first trip • If the tie switch is open then one numerical line relay will not see the fault and the feeder protection reverts back to classic coordinated time overcurrent protection

6. High-Speed Communication-Assisted Tripping & Sectionalizing Out-of-Section Faults Ground fault on transmission system

7. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Locations

8. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #1 Step 1. Trip both reclosers R1 and R2 via HSCAT scheme Step 2. Trip the tie switch S Step 3. High-speed reclose reclosers R1 and R2 Step 4. Trip and lockout recloser R1

9. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #3 Step 1. Trip both reclosers R1 and R2 via HSCAT scheme. Step 2. Trip the tie switch S. Step 3. High-speed reclose reclosers R1 and R2 (1st shot). Step 4. Trip recloser R1. Step 4. Trip and lockout sectionalizer D1. Step 5. Reclose recloser R1 (2nd shot).

10. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #5 CT locations for bus faults

11. High-Speed Communication-Assisted Tripping & Sectionalizing Complex Distribution System (Looped)

12. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #1

13. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #2

14. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #3

15. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #4

16. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #5

17. High-Speed Communication-Assisted Tripping & Sectionalizing Relay Directional Decisions

18. High-Speed Communication-Assisted Tripping & Sectionalizing Overlapping Zones of Protection (Point-to-point communications is necessary)

19. High-Speed Communication-Assisted Tripping & Sectionalizing High Speed Sectionalizing The tie switch must have a numerical control with access to the high speed communications channel so that the numerical feeder relays can send remote trip and close commands

20. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #1 Step 1. Trip both reclosers R1 and R2 via HSCAT scheme (no fault indication from D1). Step 2. High speed reclose reclosers R1 and R2. Step 3. Trip and lockout reclosers R1 and R2.

21. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #3 Step 1. Trip both reclosers R1 and R2 via HSCAT scheme (fault indication from D1) Step 2. High speed reclose reclosers R1 (1st shot) Step 3. Trip recloser R1 Step 4. Trip and lockout sectionalizer D1 Step 5. Reclose recloser R1 (2nd shot)

22. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #5 Step 1. Trip both reclosers R2 and R4 via HSCAT scheme (fault indication from D2) Step 2. Trip open tie switch S Step 2. High speed reclose reclosers R2 and R4 (1st shot) Step 3. Trip recloser R2 Step 4. Trip and lockout sectionalizer D2 Step 5. Reclose recloser R2 (2nd shot)

23. High-Speed Communication-Assisted Tripping & Sectionalizing Fault Location #7 Step 1. Trip both reclosers R2 and R4 via HSCAT scheme (no fault indication from D2 or D4) Step 2. Trip open tie switch S Step 3. High speed reclose reclosers R2 and R4 (1st shot). Step 4. Trip and lockout recloser R2 Step 5. Reclose recloser R4 (2nd shot)

24. High-Speed Communication-Assisted Tripping & Sectionalizing Special Considerations • Ground sources • Single pole tripping • Directional element polarizing quantities

25. High-Speed Communication-Assisted Tripping & Sectionalizing Ground Sources

26. High-Speed Communication-Assisted Tripping & Sectionalizing Single Pole Tripping

27. High-Speed Communication-Assisted Tripping & Sectionalizing Directional Element Polarizing Quantities Negative-sequence voltage polarized directional decision for reverse fault (CCW rotation) Negative-sequence voltage polarized directional decision for forward fault (CCW rotation)

28. High-Speed Communication-Assisted Tripping & Sectionalizing Conclusions How to perform high speed communication-assisted tripping and sectionalizing on distribution systems All faults are quickly cleared and the distribution system is rapidly sectionalized(restore service to the most customers possible) Inherent time delays embedded in the traditional approach are eliminated