NERCâ€™s Transmission Availability Data System and

New Energy Horizons Opportunities and Challenges

NERC’s Transmission Availability Data System and Common/Dependant Mode Outage Analysis

2012GM1460

Mark Lauby, IEEE Fellow

Jessica Bian, IEEE Senior Member

Andrew Slone, IEEE Member


Dependent/Common Mode TADS Outages

• Significant non‐single mode automatic AC circuit outages may create reliability risk

• Outages beyond the TPL planning criteria represent a tangible reliability threat

• Impact on disturbance events and correlation with standards

Automatic Outage Statistics

Total Automatic Outages (2008-2011)

Over 17,000

Single Mode (Sustained/Momentary)

Over 70%

Common/Dependent Mode Family (Sustained)

29.6%

Common/Dependent Mode Family (Momentary)

22.6%


TADS Events by Common/Dependent Mode and Quarter

13

12

11 10

9 8

7 6

5 4 3

0

2

4

6

8

10

12

14

16

18

Nu

mb

er

of

TAD

S Ev

en

ts

TADS Events by Common/Dependent Mode and Quarter


Impact of Common/Dependent Mode Events

14

21

8

14

6

15 17

5

10

22

14 16

3

5

3

2

2

1

3

1

3 1

0

5

10

15

20

25

30

2008Q1 2008Q2 2008Q3 2008Q4 2009Q1 2009Q2 2009Q3 2009Q4 2010Q1 2010Q2 2010Q3 2010Q4

TAD

S C

om

mo

n/D

ep

en

de

nt

Mo

de

Eve

nt

Co

un

t

Quarter

TADS Common/Dependent Mode Events Matching Event Report with Events' Total Load Loss by Quarter

Matches Event Report

Does Not Match Event Report

2483 MW

560 MW

424 MW

542 MW

0 MW

2200 MW

420 MW

351 MW

2145 MW 0 MW


Common Mode

Contamination 2%

Environmental 1%

Failed AC Circuit Equipment 3%

Failed AC Substation Equipment

18%

Failed Protection System

Equipment 8%

Fire 10%

Foreign Interference 2%

Human Error 13%

Lightning 19%

Other 3%

Power System Condition 2%

Unknown 7%

Vandalism, Terrorism, or Malicious Acts

0.2% Vegetation

0.4% Weather, excluding lightning

12%

Automatic Outages by Initiating Cause Code* (2008-2010; 1,126 Total Common Mode Outages Only)


Dependent Mode

Contamination 1%

Environmental 0.2%

Failed AC Circuit Equipment 4% Failed AC Substation

Equipment 16%

Failed Protection System Equipment

17% Fire 1%

Foreign Interference 2%

Human Error 13%

Lightning 4% Other

7%

Power System Condition 23%

Unknown 6%

Weather, excluding lightning

6%

Automatic Outages by Initiating Cause Code* (2008-2010; 1,368 Total Dependent Mode Outages Only)

*Non-single mode outages with unique event IDs and outages continued

from a previous period were removed.


Outages Initiated by Failed Protection System Equipment and PRC-005 R1

42 21 12 14 4 8 2 3 3 2 1 1 1

1 1 1

-1

0

1

2

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

PR

C-0

05

R1

Vio

lati

on

s

TADS Common/Dependent Mode Protection System Failure Outages

Circle size proportional to company (NCR) count

1 company had 1 violations and 5 common/dependent mode outages


Outages Initiated by Failed Protection System Equipment and PRC-005 R2

35 18 12 10 4 7 2 3 3 2 1 1

6 2 3 1 1

1 1 1

2

1

-1

0

1

2

3

4

5

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

PR

C-0

05

R2

Vio

lati

on

s

TADS Common/Dependent Mode Protection System Failure Outages

1 company had 2 violations and 5 common/dependent mode outages


Outages Initiated by Failed Protection System Equipment and PRC-005

• Little correlation between transmission outages and PRC-005 violations

• Is PRC-005 an effective standard? • Performance-based?

• Results-based?

• Risk-based?

• Is a focus on PRC-005 the best way to reduce CDM outages due to protection system misoperations?


Multiple Outage Voluntary Request

Non-Responses 64% 36%

Normal Clearing Events

Abnormal Clearing Events with Misoperation Contribution

Abnormal Clearing Events Without Misoperation Contribution

37%

47%

16%


Next Steps – Equipment Failure and Human Error

Weather, excluding lightning, 17%

Unknown, 14%

Lightning, 12%

Human Error, 11%

Failed AC Substation and Circuit Equipment,

20%

Failed Protection System Equipment,

8%

Power System Condition, 4%

Foreign Interference, 4%

Other, 4%


Questions and Answers


Background Materials


Definition - TADS Event and Outage Mode

• A TADS event is a transmission incident that results in the automatic outage (sustained or momentary) of one or more elements.

• Outage Mode

Outage Mode Code Automatic Outage Description

Single Mode A single element outage which occurs independently of another automatic outage

Dependent Mode Initiating A single element outage that initiates at least one subsequent element automatic outage

Dependent Mode An automatic outage of an element which occurred as a result of an initiating outage, whether the initiating outage was an element outage or a non-element outage

Common Mode One of at least two automatic outages with the same initiating cause code where the outages are not consequences of each other and occur nearly simultaneously

Common Mode Initiating A common mode outage that initiates one or more subsequent automatic outages


Definition – TADS Equipment Type

• AC Substation Equipment –

– Circuit breakers and disconnect switches which define the boundaries of an AC Circuit, as well as other facilities such as surge arrestors, buses, Transformers, wave traps, motorized devices, grounding switches, and shunt capacitors and reactors

• AC Circuit Equipment –

– Conductor, transmission structure, joints and dead-ends, insulators, ground wire, and other hardware, including in-line switches

• Protection System Equipment –

– Protective relays, associated communication systems, voltage and current sensing devices, station batteries and DC control circuitry

NERCâ€™s Transmission Availability Data System and

Documents