In the Past

  • Substation feeders were rarely metered. If they were, you'd find substation feeders metered with analog voltage and current measuring devices.
  • Eventually round, dial-type meters where replaced with first-generation electronic meters that were usually limited to Volt or Amp measurements.
  • As the technology caught up with engineering requirements, these meters evolved further into "Power" meters (with added active, reactive, and apparent power as well as PF)--yet remained largely local, read indicators-only.

 

Today

  • Protective relays in the stations include some minimal metering data; however, their primary focus remains protection.
  • The advent of greater Power Quality scrutiny makes it necessary for old Volt & Amp (V & A) measurements to account for both real-time and historical indicators.
  • All new data gathered must route back to the appropriate group to properly maintain system reliability and overall efficiency. Meeting advance communications requirements that support multiple protocols such as DNP, Modbus and now IEC61850 is essential.

 

Conclusion

  • Today's smart substation automation projects demand highly-refined, multi-function metering that supports ALL electrical and status measurements required.
  • By leveraging the advantages of new  technology in older stations you'll get increased operational awareness and support.
  • Don't try to put the proverbial round peg in a square hole--customize your meters to exactly meet your specific measurement requirements with the appropriate communications to integrate with other existing station system like RTU's.

 

Essential Smart Metering Functionality for Today's Substation and Feeder Meter Applications include (but certainly aren't  limited to):

  • Revenue Accuracy to ANSI 0.2%
  • PQ monitoring / measurements including:  Waveform capture, Sag / Swell detection, Disturbance Direction Detection, Harmonics for total and individual for V & A
  • Multi-function, local display (real time and historical trend info)
  • On-board data and event recording (on-going recording and out-of-limits based event)
  • Sequence of Events recording to 1mS
  • Selectable communications protocols
  • Easily upgrade older socket / switchboard style metering with plug and play solutions
  • Gateway functionality via serial and ethernet ports
  • Cyber security hardened

 

Finally, let's recap. "Why meter substation feeders?" By doing so you: 

  • Gain significant situation awareness visible across multiple groups such as Substation Engineering, SCADA, Metering. 
  • Improve station reliability so you can meet and maintain public utility commission requirements.  Improved traceability provides better technical assessment of both real-time load conditions as well as post event analysis and documentation.
  • Eliminate the need to maintain multiple pieces of equipment as well as training personnel on various types and manufactures with multi-function devices that directly contribute to equipment and cost reduction.

 

For a more in-depth assessment of how intelligent metering improves electrical operations of any substation environment, please consult with your Schneider Electric Utility Metering Applications Engineering staff. Paul Golden Carlos Tello Scott Laster Michael Neas Matthew Anthony Art Nekrasov