protection challenges for north america’s first combined...

42
Protection Challenges for North America’s First Combined Cable / Overhead Double-Circuit 500 kV Transmission Line With Mutual Coupling Denis Bucco, Curtis Sanden, Arturo Torres, and Edward Wong Southern California Edison Jordan Bell, Normann Fischer, and John Thompson Schweitzer Engineering Laboratories, Inc. Copyright © SCE and SEL 2017

Upload: dangdien

Post on 05-Jun-2018

216 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Copyright © SEL 2017

Protection Challenges for North America’s First Combined Cable / Overhead

Double-Circuit 500 kV Transmission Line With Mutual Coupling

Denis Bucco, Curtis Sanden, Arturo Torres, and Edward Wong Southern California Edison

Jordan Bell, Normann Fischer, and John ThompsonSchweitzer Engineering Laboratories, Inc.

Copyright © SCE and SEL 2017

Page 2: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Project Background

• New 75-mile 500 kV transmission line• Single-circuit and double-circuit construction• Protection package System A – Line current differential

System B – Directional comparison blocking

System C – Permissive overreaching transfer trip

Page 3: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Decreasing Land Availability…

CSUSB WRI ©

© 2016 Google

Page 4: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

From Overhead…

To Underground

Page 5: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

TransitionTowers

East

West

Page 6: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Cable Layout

Page 7: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Vaults and Terminations

Page 8: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Overall Line Composition

Page 9: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Line Section 1: 33 Miles

• Two conductors per phase• Segmented ground wires

Page 10: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Line Section 2: 28 Miles

• Two conductors per phase• Segmented ground wires

Page 11: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Line Section 3: 4 Miles

• Underground• Two cables per phase

Page 12: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Line Section 4: 8 Miles

• Line 1: 500 kV line• Line 2: Future 500 kV line

Page 13: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Impedance Comparison

UndergroundZ1 = 0.02 + j0.31 = 0.31 ∠86° ohms / mile

Z0 = 0.20 + j0.13 = 0.24 ∠33° ohms / mile

OverheadZ1 = 0.05 + j0.58 = 0.58 ∠85° ohms / mile

Z0 = 0.44 + j2.13 = 2.17 ∠78° ohms / mile

Page 14: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

IG ~ 0

Ground Wire Segmentation

• Phase conductors induce voltage in ground wire• Induced voltage leads to circulating current and losses

• Segmenting ground wires prevents circulating current

IG ≠ 0

Page 15: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Line Impedance Calculation

Where:

ZAA = Self impedance

ZAB and ZBC = Mutual impedance between phases

ZAA′, ZAB′, and ZAC′ = Mutual impedance between the A-phase conductor Line 1 and φ-phase conductor Line 2

VADROP = ZAA • IA + ZAB • IB + ZAC • IC + …ZAA′ • IA′ + ZAB′ • IB′ + ZAC′ • IC′

Page 16: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Put in Matrix Form…

VADROP

VBDROP

VCDROP

VAʹDROP

VBʹDROP

VCʹDROP

ZAA ZAB ZAC ZAAʹ ZABʹ ZACʹ

ZBA ZBB ZBC ZBAʹ ZBBʹ ZBCʹ

ZCA ZCB ZCC ZCAʹ ZCBʹ ZCCʹ

ZAʹA ZAʹB ZAʹC ZAʹAʹ ZAʹBʹ ZAʹCʹ

ZBʹA ZBʹB ZBʹC ZBʹAʹ ZBʹBʹ ZBʹCʹ

ZCʹA ZCʹB ZCʹC ZCʹAʹ ZCʹBʹ ZCʹC

IA

IB

IC

IAʹ

IBʹ

ICʹ

•=

Page 17: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

…Then Sequence Domain

Z0 w x Z0M wm xm

w Z1 y wm z1m ym

x y Z2 xm ym z2m

Z0M wm xm Z0ʹ xʹ yʹ

wm z1m ym xʹ Z1ʹ zʹ

xm ym z2m yʹ zʹ Z2ʹ

=(Z012)

Line 1 Mutual

Mutual Line 2

Page 18: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Parallel Line Apparent Impedance

ZS_TERM = m • ZL1 (1 – ½ m)

ZT_TERM = ½ • ZL1 • (1 – m2)

Page 19: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Double-Circuit Apparent Impedance

0

2

4

6

8

10

0% 20% 40% 60% 80% 100%

Ohm

s Se

cond

ary

TheoreticalApparent

Page 20: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Sequence Impedance Through Energization

Positive-sequence Zero-sequence

Page 21: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Impedance Calculation

Matrix calculationZ1 = 3.26 + j33.32 Ω

Z0 = 24.73 + j142.65 Ω

EnergizationZ1 = 3.56 + j33.92 Ω

Z0 = 25.30 + j144.80 Ω

Page 22: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Charging Current Leads to High Voltage

Distributed capacitance charging current

Total charging current

Voltage rise

Page 23: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Charging Current Leads to High Voltage

≈ 2 amperes per mile overhead≈ 40 amperes per mile underground

Ph Ph1_CHRG 1

VI j C3−= ω

550

560

570

580

590

0 10 20 30 40 50 60 70

Volta

ge (k

V)

Line Distance (Miles)

Vincent

Page 24: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Protection System Validation

• Reduce short-circuit model to area of interest• Maintain 500 kV system with boundary equivalents• Build model in real-time digital simulator • Choose realistic operating conditions• Integrate physical relays with simulation

Page 25: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Protection System ValidationTest Plan

• Basic internal and external faults• Line energization and load pickup• Zone 1 margin• High-impedance faults• Batch tests

Page 26: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Batch Tests

• All internal and external fault locations (21 internal and 10 external)

• Ten fault types (AG, BG, CG, ABG, BCG, CAG, AB, BC, CA, and ABCG)

• Four fault inception angles (0, 30, 60, and 90 degrees)• All load flow cases

Page 27: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Distance Element Performance

0.0

2.0

4.0

6.0

4.5 3.3 2.2 1.1 0.0Mea

sure

d Im

peda

nce

(Ohm

s)

Theoretical Impedance (Ohms)

Mira Loma

0.0

2.0

4.0

6.0

0.0 1.5 3.0 4.5 6.0

Mea

sure

d Im

peda

nce

(Ohm

s)

Theoretical Impedance (Ohms)

Vincent

Page 28: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Zone 1 PerformanceManufacturer A

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

Ope

ratio

ns

Fault Location

Page 29: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Zone 1 PerformanceManufacturer A

Zone 1 PerformanceManufacturer A

3

3.5

4

4.5

5

5.5

6

6.13 6.50 6.88 7.25 7.63 8.00 8.38

Impe

danc

e (O

hms)

Time (Cycles)

Page 30: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Modify Settings and RepeatManufacturer A

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

Ope

ratio

ns

Fault Location

Page 31: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

How Did the Other Relay Do?Manufacturer B

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

Ope

ratio

ns

Fault Location

Page 32: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Manufacturer A Distance Performance

0.0

0.8

1.5

2.3

3.0

0% 20% 40% 60% 80% 100%

Ope

ratin

g Ti

me

(Cyc

les)

Fault Location

Page 33: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Manufacturer B Distance Performance

0.0

0.8

1.5

2.3

3.0

0% 20% 40% 60% 80% 100%

Ope

ratin

g Ti

me

(Cyc

les)

Fault Location

Page 34: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Manufacturer B Differential Performance

0.0

0.8

1.5

2.3

3.0

0% 20% 40% 60% 80% 100%

Ope

ratin

g Ti

me

(Cyc

les)

Fault Location

Page 35: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Impedance-BasedFault LocatorManufacturer A

0.0

5.0

10.0

15.0

20.0

0.0 11.2 22.4 33.6 44.8 56.0 67.2Faul

t Loc

atio

n E

rror

(Mile

s)

Fault Location (Miles)

0.0

5.0

10.0

15.0

20.0

0.0 11.2 22.4 33.6 44.8 56.0 67.2Faul

t Loc

atio

n E

rror

(Mile

s)

Fault Location (Miles)

Page 36: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Traveling-Wave Fault Locator

• Explored to evaluate functionality on this composite line• Simulated in non-real time• Saved waveforms and replayed into the relays• Evaluated the relay response

Page 37: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Traveling-Wave Reflections

LL1, V1 LL2, V2 LL3, V3 LL4, V4

t0

t1

t2

t3t4

OpenClosed

IncidentReflectedJunction

Page 38: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Traveling-Wave Waveform

-5.0

-3.0

-1.0

1.0

3.0

5.0

Cur

rent

Mag

nitu

de(A

mpe

res

Seco

ndar

y)

Time (Cycles)

Page 39: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Traveling-Wave Measurements

-100

-60

-20

20

60

0 160 320 480 640 800 960 1,120

Trav

elin

g-W

ave

Mag

nitu

de

(Am

pere

s)

Time (Microseconds)

t0

t1

t2

t3 t4

Page 40: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Traveling-Wave Fault Locator Accuracy

-0.40

-0.20

0.00

0.20

0.40

0.60

0.00 18.67 37.34 56.01 74.68

Faul

t Loc

ator

Err

or

(Mile

s)

Line Length (Miles)

Page 41: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Summary

• Transmission line incorporated underground cables• Protection scheme needed reevaluation to include

multiple line current differential relays• Real-time digital simulation validated relay performance

Page 42: Protection Challenges for North America’s First Combined ...prorelay.tamu.edu/wp-content/uploads/sites/3/2017/04/1-Protection... · Positive-sequence. Zero-sequence. Impedance Calculation

Questions?