ABSTRACT: This paper describes the evolution of a system for automated analysis of transmission line faults. The analysis is based on the substation data primarily collected from digital fault recorders. The paper provides a historical overview of the implementation steps and illustrates requirements changes throughout the process. In addition, the paper shares some interesting experiences related to the usage of the system that illustrate the value and benefits of having the automated fault analysis solution in place. The encounters include events developed during hurricanes Rita and Ike, as well as events during dry weather in 2011. The solution for automated fault analysis played important role in diagnostics and system restoration process. (PRESENTED AT 2014 FDA CONFERENCE AT GEORGIA TECH)

1. M . K E Z U N O V I C
D . S E V C I K
R . L U N S F O R D
B . C L O W E
T . P O P O V I C
2 0 1 4 G E O R G I A T E C H A N N U A L
F A U L T & D I S T U R B A N C E A N A L Y S I S C O N F E R E N C E
20 Years and Counting: Deploying
a System for Automated Analysis of
Transmission Line Faults

2. CenterPoint Energy
Gas and electric delivery
company operating in
several states.
CenterPoint Energy
Houston Electric (CEHE) is
a structurally unbundled
transmission and
distribution utility serving
Houston, Galveston,
Freeport, Baytown, and
surrounding communities in
the state of Texas.
CEHE does not own or
operate power plants, nor
does CEHE participate in
competitive electric energy
markets.
CEHE (17 GW summer
peak) has a small
geographic footprint, but
serves approximately 25% of
the electric load in the
ERCOT region.
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

3. Introduction
Developing a system for
automated fault and
disturbance analysis at
CenterPoint Energy
 Historical overview during last 20
years
 Designing and growing an
automated system for fault data
analysis
 Experiences during some major
events
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

4. Background
From magnetic tape
fault recorders to
modern IEDs and
automated analysis
 Magnetic tape recorders prior
1980’s
 Introduction to digital fault
recorders (DFRs) in 1985
 All the DFRs have been updated
(couple of generations)
 Implementing a system for fault
analysis to improve data
utilization
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

5. Developing a
prototype
Early 90s at Texas A&M
University
 Proof of concept
 Signal processing and expert
system rules
 Based on EMTP simulation and
some field data
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

6. Field Trials
Mid-90s
 Single substation
 Direct communication to a DFR
 Reporting results via fax
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

7. Commercial
deployment
Early 2000s
 Around 10 DFRs
 Slow deployment: reliability
issues with installed PCs
 New DFRs introduced mixture of
types and vintages
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

8. New
requirements
Improving the
configuration
management
 Better configuration management
 New generation of DFRs
(combining types and vintages)
 Need for improved GUI
 Improved data management tools
 NERC requirements
 Considerations to include digital
protective relays (DPRs)
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

9. First
generation
Fully deployed by
mid-2000s
 Over 30 substations
 Web interface
 Email/pager reporting
 Need for improved GUI
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

10. Second
generation
Application server
updated in 2013
 Centralized client/server solution
configured for ~ 100 IEDs
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

11. Data
management
tools within
the GUI
Quick data checks and
improve the ability of
users to filter and sift
the data, enhancing the
process of drilling down
to the required data-set.
Time-stamping the data
upon arrival and
processing by the
automated fault
analysis solution.
 Waveform preview window
 Processed vs Event date/time
 1-End vs 2-End location
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

12. Encounters
and
testimonials
Hurricane Rita in 2005
 Sep 24, 2005, Hurricane Rita
 Damage to the system assessed
almost exclusively from the
reports produced by the solution
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

13. Encounters
and
testimonials
Events in March 2006
 Mar 28, 2006, major event in the
138 kV electrical system
 A total of 11 records by 3 different
DFRs
 Multiple contingencies and
delayed fault clearing
 The automated analysis provided
quick snapshot overview of the 11
records and greatly reduced the
time needed to identify and assess
critical events.
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

14. Encounters
and
testimonials
Hurricane Ike in 2008
 90% customers lost power
 99 transmission lines locked out
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

15. Encounters
and
testimonials
Dry season in 2011
 Late 2010 and early 2011 dry period
 Excessive buildup of contaminates
on insulators and equipment
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference

16. Conclusions
Time period of over 20
years
 Historical overview of the
development and deployment
 The latest generation installed at
CNP configured for ~100 IEDs,
mainly DFRs
 Automated data collection and
fault analysis have important role
in system restoration
 Encounters and use illustrated
with examples from major events
such as hurricanes and dry season
© 2014 Kezunovic, Sevcik, Lunsford, Clowe, Popovic; presented at 2014 Georgia Tech Fault and Disturbance Conference