Synchronized Event Data Reporting

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Synchronized Event Data Reporting

• Working Group SP-6
• March 10, 2005

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Objective

• Take advantage of lessons learned to improve the
  ability of NPCC to quickly and accurately
  establish the sequence of events following any
  future wide area disturbance

3
Scope

• Investigate the area of synchronized event data
  reporting prepare a report for NPCC (consider
  synchronization of DFRs, DSRs, SERs, SCADA/EMS,
  PMUs, Relays)
• Address maintenance of clocks, recorders,
  SCADA/EMS equipment
• Update survey of Disturbance Recording Devices
  (DFRs, DSRs, SERs) and add relays, time
  synchronization, monitoring of sync

4
Scope (Cont.)

• Develop format for reporting of wide-area event
  data
• Make recommendations for improvements to NPCC
  Criteria (incl. deployment, cost analysis
  benefits)
• As necessary, develop guide documents

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NERC Recommendations

• Recommendation 12a The reliability regions,
  coordinated through the NERC Planning Committee,
  shall within one year define regional criteria
  for the application of synchronized recording
  devices in power plants and substations. Regions
  are requested to facilitate the installation of
  an appropriate number, type and location of
  devices within the region as soon as practical to
  allow accurate recording of future system
  disturbances and to facilitate benchmarking of
  simulation studies by comparison to actual
  disturbances.
• Recommendation 12b Facilities owners shall, in
  accordance with regional criteria, upgrade
  existing dynamic recorders to include GPS time
  synchronization and, as necessary, install
  additional dynamic recorders.

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Existing Criteria

• A-2, 2.3 - Areas shall install dynamic recording
  devices and provide recorded data necessary to
  enhance analysis of wide area system disturbances
  and validate system simulation models. These
  devices should be time synchronized and should
  have sufficient data storage to permit a few
  minutes of data to be collected. Information
  from these devices should be used in tandem, when
  appropriate, with shorter timescale readings from
  faults recorders and sequence of events recorders
  (SER)

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Existing Criteria (Cont.)

• A-5, 2.7.2 states Event and fault recording
  capability should be provided to the maximum
  practical extent to permit analysis of system
  disturbances and protection system performance.
  It is recommended that these devices be time
  synchronized.

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Findings

• Existing Criteria werent measurable
• Time Zone should be specified with reported event
  data
• Accuracy is a subject Uncertainty is a measure
• Uncertainty of IRIG-B from a GPS clock is lt 1ms
• In most areas, an uncertainty of /-2 ms for all
  DRE is a reasonable goal (stretch goal for
  relays)
• Survey summary contains data for 298 stations

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Survey Summary

• DFRs
• 239 Stations in NPCC (5 Oscillographs)
• 184 Stations use GPS synchronization
• 47 are synchronized by other means
• 98 have Monitoring of the sync signal
• 34 more DFRs planned Not all at new sites

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Survey Summary (Cont.)

• DSRs
• 39 Stations in NPCC have DSRs (1 OOS)
• 36 are GPS synchronized
• 1 is synchronized by other means
• 14 have Monitoring of the sync signal
• 21 more are planned Takes advantage of dual
  capabilities of DFRs

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Survey Summary (Cont.)

• SERs
• 178 Installations in NPCC - Many stations get
  this capability thru RTUs. Perhaps many more have
  it via existing RTUs.
• 131 use GPS for synchronization
• 43 are synchronized by other means
• 36 have Monitoring of the sync signal
• Stand-alone SER generally not planned.

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Survey Summary (Cont.)

• Relays as DRE
• Intended to identify use in lieu of DFR
• Installed at many terminals throughout NPCC
• Many reported arent synchronized
• Time stamps may be less accurate than DFR (even
  with GPS synchronization)
• Limited sampling rate, memory, record length
• PMUs
• 13 Installed / 4 Planned In three Areas

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Conclusions

• All disturbance recording equipment should be GPS
  synchronized
• SCADA/EMS should be GPS synchronized and designed
  to minimize time skew for SOE
• Communication protocols that support transport of
  the time stamp from the RTU to the SCADA master
  and between control centers should be implemented
  (as software is upgraded)
• RTUs should be GPS synchronized (going forward)

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Conclusions (Cont.)

• DFR capability should be installed at all Bulk
  Power System transmission facilities
• TFSS should review DSR installations to determine
  if other locations are required
• DFR redundancy is provided by overlapping
  coverage
• Digital relays provide good backup event
  recording capability
• Monitoring should be provided for loss of
  synchronization by the GPS clock and DREs

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WG Members

• John Ferraro Northesat Utilities Chairman
• James Allcorn - NYISO
• Hung Huynh - Nova Scotia Power
• Jim Ingleson NYISO
• Quoc Le NPCC
• Xiaochuan Luo - ISO-New England
• Laurie Martuscello - National Grid
• Anthony Napikoski - United Illuminating
• Jeff Pond - National Grid
• Vasilios Tsolias - National Grid
• Gary Young - BC Hydro Liaison with WECC

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Whats Next?

• Prepare recommendations for revisions to Criteria
  Documents including cost benefits data
• Prepare recommendations (if any) for revisions to
  Guide and Procedure Documents