2014ieeepes-comedurdfault-gubala ...grouper.ieee.org/groups/td/dist/sd/doc/2015-07 urd cable...

URD Cable Fault Prediction Model

1

Christopher GubalaComEd

General Engineer – Reliability Analysis

2014 IEEE PES General MeetingUtility Current Practices & Challenges of Predictive Distribution Reliability

2

ComEd, An Exelon Company

Chicago

Illinois

• 3.8 million electric customers in northern Illinois, including the City of Chicago

• Service Territory: 11,300 square miles

• Peak Load: 23,753 MW (7/20/2011)

• 2011 Rate Base: $8.6 billion

• 1.5 million poles

• 530,000 distribution transformers

• 65,000 circuit miles of primary distribution

• 54% overhead, 46% underground

• 5,800 circuit miles of transmission

• Including 2nd largest underground network in the U.S. (390 miles)

• 882 substations

• 350 transmission-connected, 532 distribution-connected

• 29,084 MW of connected generation, including:

• 10,700 MW of connected nuclear

• 2,327 MW of connected wind

• Additional 14,829 MW of wind generation in the PJM queue

2

3

World Continues to Evolve & Advance……..Reliable and Quality Power

3

Energy Infrastructure Modernization ActOn October 27, 2011, the Illinois General Assembly enacted the Energy Infrastructure

Modernization Act (EIMA), setting in motion a $2.6 billion investment by ComEd to

strengthen and modernize the state’s electric grid.

The Investment Plan has two primary components:

•Reliability-Related Investments– 5 year program, $1.3B

– Underground cable – mainline, URD, manholes

– Ridgeland 69kV cable replacement

– Training centers

– Wood pole inspection, reinforcement/replacement

– Storm hardening – undergrounding, spacer cable

•Smart Grid-Related Investments – 10 year program, $1.3B

– Distribution Automation

– Smart Substations

– Smart Meters

4

4

Reliability Related InvestmentsUnderground Cable Storm HardeningStorm HardeningStorm HardeningStorm Hardening Wood PolesWood PolesWood PolesWood Poles

• 5 -year , $75M program

• Inspection of 733,000 wood poles to determine need for replacement or reinforcement

• Replace or reinforce an estimated 19,000 poles

• 5-year , $1.0B program

• Remediate 4,300 miles of underground residential cable

• Assessment and refurbishment of 32,000 manholes

• Replacement of 660 miles of mainline cable

• Testing of 925 circuit sections

• Replacement of 10 miles of high voltage (69kV) cable

• 5 year , $201M program

• Designed to further reduce the susceptibility of circuits to storm related damage

• Engineered solutions include but not limited to, overhead to underground conversion, installation of tree-resistant conductors, and additional vegetation management

$10M Program: Construction of two new facilities – one in Chicago and one in Rockford – to provide electric and customer operations training

5

Smart Grid Related InvestmentsSmart Meters Distribution AutomationDistribution AutomationDistribution AutomationDistribution Automation Intelligent SubstationsIntelligent SubstationsIntelligent SubstationsIntelligent Substations

• 5 -year , $77M program

• Modernize 10 substations

• Asset health monitoring software

• Upgrade electro-mechanical relays to microprocessor-based

• Upgrade older air magnetic breakers to modern vacuum breakers

• Install transformer monitoring

• Install monitoring on station batteries and 138kV breakers

• 10-year , $950M program

• Replace all retail meters with smart meters (approx. 4M)

• Deploy Silver Spring Networks Advanced Metering Infrastructure (AMI)

• Two-way communications

• Supports other customer services and Smart Grid applications

• 5 year , $244M program

• Expand self healing grid technology with automatic sectionalizing devices and advanced control systems

• Install 2,500 12kV devices and 100 34kV devices

• Upgrade software for 800 devices to enhance protection schemes

• Convert radio network from Utilinet to Silver Springs Network (8,000 radios)

Cyber Secure Communications: Secure, tiered, robust communications architecture aligned with industry best practices and national security standards with capacity to meet the current and future requirements of the Smart Grid

6

URD Cable vs. Faults• ~21,000 miles URD cable on the System

– ~8,700 miles or 41% Bare Concentric Neutral URD Cable; purchased between 1966-1985– ~12,300 miles or 59% Jacketed Concentric Neutral URD Cable; purchased from 1986 to current

• ComEd’s URD failures cluster around aging bare concentric cable which was installed/purchased during the period 1966 to 1985 (~8,700 miles)

– 92% of historical faults was on cable installed before 1986

7

0

1,000

2,000

3,000

4,000

5,000

6,000

0

1,000

2,000

3,000

4,000

5,000

6,000

19

62

19

64

19

66

19

68

19

70

19

72

19

74

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

20

06

20

08

UR

D F

au

ltsE

st.

Ft.

of

Cab

le I

ns

tall

ed

(T

ho

us

an

ds

) Est. Ft of Cable Installed

# Of Faults 1998-2012

URD Fault Predicative ModelThrough Regression Analysis, our URD Fault Predicative Model incorporates

weather factors at O’Hare Airport on a monthly basis:

•Sum of Cooling Degree Days

•Sum of Cooling Degree Days (T-1)

•Sum of Precipitation

•# of days that reach ≥ 90°F

•# of days that reach ≥ 95°F

•Sum of Lightning strokes

Area of opportunity is to include Daily Extremes:

•2013 Flooding & Rain Events

•2014 Snow Melting Events

8

Projection: Start of the Year using avg Historical Weather

YEAR MONTH

Actual

URD

Faults

Actual

YTD

URD

Faults

CDD:

Cooling

Degree

Days

PRECIPITATION

# OF

DAYS

TMAX ? 90°

# OF

DAYS

TMAX ? 95°

LIGHTNING

STROKESCDD YTD

2014 1 0 - 0 1.90 0 0 1,111 0

2014 2 0 - 0 2.02 0 0 684 0

2014 3 0 - 3 2.40 0 0 6,464 3

2014 4 0 - 9 3.87 0 0 15,597 12

2014 5 0 - 54 4.37 1 0 43,981 67

2014 6 0 - 182 3.72 4 0 60,824 249

2014 7 0 - 315 4.12 7 2 107,156 564

2014 8 0 - 256 4.50 4 1 92,326 820

2014 9 0 - 97 3.45 1 0 13,374 917

2014 10 0 - 13 2.79 0 0 7,594 930

2014 11 0 - 0 2.20 0 0 2,730 930

2014 12 0 - 0 2.40 0 0 401 930

YEAR MONTH

Actual

URD

Faults

Actual

YTD

URD

Faults

CDD:

Cooling

Degree

Days

PRECIPITATION

# OF

DAYS

TMAX ? 90°

# OF

DAYS

TMAX ? 95°

LIGHTNING

STROKESCDD YTD

2014 1 332 332 0 2.81 0 0 8 0

2014 2 321 653 0 2.48 0 0 884 0

2014 3 336 989 0 1.89 0 0 284 0

2014 4 334 1,323 1 2.84 0 0 8,675 1

2014 5 476 1,799 60 4.98 0 0 32,836 61

2014 6 690 2,489 198 7.81 2 0 164,623 259

Actual: Weather

2013 Daily Graph: URD Faults vs. Precipitation/CDDs• URD faults increase when there’s more than ¾” of rain (2013: 16 days vs. Mean: 14 days). URD faults

also increase the day following these days (2013: +14 days vs. Mean: +11 days)

– 5 days above the average (2013: 30 days vs. Historic Mean: 25 days)

• The flooding event (5.55”) on April 17th – 19th (3 Days) accounted for 106 faults

– Historically, on average 10 URD faults/day in April; during the flood event URD faults were 76 faults unfavorable

(Actual: 106 faults vs. Predicated: 30 faults)

• The rain event (1.78”) on January 29th – 30th (2 Days) accounted for 59 faults

– Historically, on average 8 URD faults/day in January; during the rain event URD faults were 43 faults unfavorable

(Actual: 59 faults vs. Predicated: 16 faults)

• 2013 Weather Normalization (Flood & Rain Adjusted) = 5,899

– 6,018 Actual – 76 – 43 = 5,899 Weather Normalized

9

29.1 27.7

66.9

0

10

20

30

40

50

60

70

80

Snowfall (in Inches)Jan - June

2014 Daily Graph: URD Faults vs. Snow Melt• Through March, O’Hare’s snow total of 80.6” was the 3rd snowiest season (July

1st-June 30th) going back to the 1884-1885 season, 1978-79 was snowiest with

89.7” of snow.

– Midway’s snow fall total of 86.8” was the 2nd snowiest season.

– Per the National Weather Service, 2014 winter, December 2013 to March 2014, was

the coldest in Chicago history going back to 1872 with an average temperature of 22.0°.

The previous record for the coldest December to March period was 1903-1904 at 22.3°

• Over 60” of snow melted in three major events this year (Jan 10th – 11th, Feb

20th – 21st, Mar 10th – 11th)– These events include the day of the snow melt and the day proceeding (6 days) accounting for

147 URD faults which were 95 faults unfavorable (Actual: 147 faults vs. Projected: 52 faults)

10

26

14

42

17

2523

19.9"

32.9"

7.6"

0

5

10

15

20

25

30

35

0

10

20

30

40

50

60

01

-Ja

n-1

4

03

-Ja

n-1

4

05

-Ja

n-1

4

07

-Ja

n-1

4

09

-Ja

n-1

4

11

-Ja

n-1

4

13

-Ja

n-1

4

15

-Ja

n-1

4

17

-Ja

n-1

4

19

-Ja

n-1

4

21

-Ja

n-1

4

23

-Ja

n-1

4

25

-Ja

n-1

4

27

-Ja

n-1

4

29

-Ja

n-1

4

31

-Ja

n-1

4

02

-Fe

b-1

4

04

-Fe

b-1

4

06

-Fe

b-1

4

08

-Fe

b-1

4

10

-Fe

b-1

4

12

-Fe

b-1

4

14

-Fe

b-1

4

16

-Fe

b-1

4

18

-Fe

b-1

4

20

-Fe

b-1

4

22

-Fe

b-1

4

24

-Fe

b-1

4

26

-Fe

b-1

4

28

-Fe

b-1

4

02

-Ma

r-1

4

04

-Ma

r-1

4

06

-Ma

r-1

4

08

-Ma

r-1

4

10

-Ma

r-1

4

12

-Ma

r-1

4

14

-Ma

r-1

4

16

-Ma

r-1

4

18

-Ma

r-1

4

20

-Ma

r-1

4

22

-Ma

r-1

4

24

-Ma

r-1

4

26

-Ma

r-1

4

28

-Ma

r-1

4

30

-Ma

r-1

4

Accu

mla

ted

Sn

ow

(in In

che

s)

UR

D F

au

lts

& °F

Snow Melt & URD Faults

URD Faults Avg Temp Acc Snow

Conclusion• Our URD Fault Weather Model does well by incorporating

weather factors on a monthly basis from a centrally located

point (O’Hare Airport)

– 2012 and 2013 URD Faults were within ± 5% of the projection

• Extreme Weather in all types have impacted our Service Area

the past couple of years and Daily Extremes can be offset

when grouping weather totals by month

• We currently analyze Extreme Daily Outliers on a case-by-case

basis and are looking into other data sets which can aid in

incorporating these Extremes

– River Levels which correlate to Ground Saturation via Snow Melt

– Daily Model vs. Monthly Model

11

Questions?

Thank You

12