Autonomous TeleInformation Network for Power Systems Switchgear Equipment eDiagnostics

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Autonomous Tele-Information Network for Power
Systems Switchgear Equipment e-Diagnostics
A. Lisowiec1, A. Nowakowski1, Z. Kolodziejczyk1,
B. Miedzinski2 1Centre For Tele-Information
Systems and Hardware Applications, Tele and Radio
Research Institute 2Institute of Electric Power
Engineering, Wroclaw University of Technology
The research work presented in this paper is part
of a development project cofounded by European
Union within the European Union Structural Funds,
POIG (Operational Programme Innovative Economy),
project number WND-POIG.01.03.01-14-141/08.
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Reasons for developing a comprehensive system for
Circuit Breaker diagnosis

• Circuit breakers have to be reliable since the
  safety of power network operation depends
  directly on them,
• Circuit breakers are the elements of power
  network that are more susceptible to damage than
  other equipment,
• Circuit breakers are expensive to replace

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Basic requirements on the diagnostic system

• The diagnosis of the CB has to be done on-line
  basing on the signals available during normal
  operation,
• Data acquisition has to be carried out by devices
  that can also perform other functions like
  protection relay,
• The transmission of all data within the system
  has to be carried out according to IEC 61850
  standard,
• The decision/diagnosis of the CB has to be
  carried out autonomously by the network without
  any interference from human operator

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System architecture
SUBSTATION 1
SUBSTATION ETHERNET BUS
CT D
CT D
CONC
CB
CB
TCT/IP
TCT/IP
TCT/IP
REMOTE OPERATOR
SUBSTATION 2
TCT/IP
CORPORATE
CONTROL
TCT/IP
CENTRE
SUBSTATION N
CDB
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Control device, CTD, architechture
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Conventional method of CB monitoring
Signals acquired from Circuit Breaker can be
grouped according to different criteria

• analog signals,
• digital signals

• high speed signals,
• slowly varying signals

• signals at high voltage,
• signals at low voltage

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Main signals acquired from CB

• auxiliary contact signals
• truck position contacts,
• main spring tension state contact
• sensor signals,
• eg. sulfur hexafluoride pressere sensor signal,
• vibration signals,
• temperature measurement sensors,
• dc voltages

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Main signals acquired from CB

• phase currents,
• currents and voltages of tripping and closing
  coils,
• movement monitoring sensors signals,
• acceleration sensors signals,
• digital signals,
• open initiate,
• close initiate,

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Concentrator software architecture
DIGITAL FILTERING MODULE
SIGNAL PARAMETRIZATION MODULE
EXSPERT SYSTEM MODULE
ALARMS NOTIFICATION AND REPORT GENERATION MODULE
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Signal parametrization methods

• Digital filtering,
• Resampling in digital domain for protection
  functions realization,
• Decimation for recorder purposes,
• Spectrum analysis, FFT,
• Wavelet analysis

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Analysis of current and voltage signals

• Contacts bounce time,
• Contact opening time and its dependence on load
  current,
• Contact closing time and its dependence on load
  current,
• Simultaneity of contacts closing in three phases
  and its dependence on load current,

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Analysis of current and voltage signals, cnt.

• Contact closing time averaged over last 10
  operations,
• Contact closing time averaged over last 10
  operations,

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Expert system operation
EVENT CLASSIFICATION e.g. CB tripping Based on
the event, appropriate set of rules customized
for each CB operation is used
SIGNAL CHARACTERIZATION AND VERIFICATION Each
signal describing the event is analyzed based on
the rules of the expert system knowledge base.
The purpose of this is to verify that the values
of extracted signal features conform to the
expected values within given tolerances
VERIFICATION OF CAUSE EFFECT RELATIONSHIP AMONG
SIGNALS the relationships involving multiple
parameters and possibly multiple signals are
analyzed to determine the causes of observed
signal features
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Expert system operation, cnt.
CB OPERATION VERIFICATION The actual breaker
operation is compared with the patterns stored in
the rules of the expert system and the settings,
each of them customized for particular type of
circuit breaker and operation and specified by
user
ANALYSIS REPORT GENERATION At the end of the
analysis, expert system creates the report in the
form of a text file. The report clearly describes
the operation and performances of the circuit
breaker, as well as maintenance and repair
recommendations if problems are detected.
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Operating coil current diagram
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New non invasive methods of Circuit Breaker
monitoring

• Temperature distribution monitoring
• Spectroscopic methods

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Temperature distribution monitoring
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Temperature distribution monitoring
Taking the temperature distribution within the
contact body
Comparing the taken temperature distribution with
the reference temperature distribution
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Temperature distribution within the contact body
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Spectroscopic method setup
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Spectroscopic methods
Special construction of the contact body
Knowledge of the characteristic spectral lines of
the materials used for contact construction
Selective diode detectors
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Special construction of the moving part of the
contact
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Emission spectrum of contact compound made of
Molybdenum
arc arching discharge, glow glowing
discharge, dat data from physico-chemical tables
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Emission spectrum of contact compound made of
Tantalum
arc arching discharge, glow glowing
discharge, dat data from physico-chemical tables
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Emission spectrum of contact compound made of
Nickel
arc arching discharge, glow glowing
discharge, dat data from physico-chemical tables
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Conclusion

• The developed network is a very comrehensive
  system for CB testing and diagnosis on-line it
  employs traditional as well as new methods of CB
  monitoring
• The cost to the final user has been minimalized
  because of the integration of protective, control
  and monitoring function in one device
• The system uses modern approach through the
  adoption of IEC 61850 standard

The research work presented in this paper is part
of a development project cofounded by European
Union within the European Union Structural Funds,
POIG (Operational Programme Innovative Economy),
project number WND-POIG.01.03.01-14-141/08.