Efficient Fault Management using Remote Fault Indicators

Transcription

1 Efficient Fault Management using Remote Fault Indicators Dr. Eilert Bjerkan Nortroll AS

2 Contents: Introduction Detection Methods Advantages with Remote Fault Indicators (Remote FPIs) Communication options Summary and conclusions

3 Introduction: SCADA System Gateway I 0 < Transm ission system 60/20 kv I 0 < I 0 < I 0 <

4 Introduction: Electronic FPIs since late 70 s Mixed experience with FPIs due to: Incorrect settings Inflexibility Suitability Incorrect installation Variable product quality

5 Increasing requirements to Quality of Supply SMART GRIDS

6 Fault types I<<: Phase to Phase Faults (Overcurrent) I 0 <: Cross-country Faults (Double Earth-faults) EF: Phase to ground faults (Earth faults) DBC: Downed or Broken Conductors.

7 Detection Methods Ammetric detection (Current treshold non-directional) Absolute treshold di/dt (rapid increase relative to load current) Proportional treshold (relative to load current) Transient detection (zero sequence transients I 0 /U 0 ) Wattmetric detection (zero sequence 50Hz I 0 /U 0 ) Negative Sequence (DBC) Differential Methods (combined methods and synchronized measurements)

8 Distributed Generation and meshed networks Traditional FPI methods may fail to detect faults in such networks. Possible solutions: Transient method could be an alternative for Eartfaults. Automated Intertripping Reclosing counter Differential measurements Directional 50 Hz principles

9 Remote FPI Live Test Example Live test of Remote FPIs in compensated 22 kv network in Ireland (ESB Networks) 12 Directional FPIs (DFIs) with remote comms. SMS-based Remote Communication to SCADA-system 6 Phase-to-ground fault tests successfully detected. Detailed localization in very short time

10 The Remote FPI

11 Fault Location

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13 Communication alternatives 1. Relay interface (cable to RTU) 2. Short range radio to RTU or Hub/Concentrator 3. Serial bus/communication to RTU or Hub/Conc. 4. GSM/GPRS Communication 5. Trunked radio systems for long distance comm. 6. Others: Fiber, Twisted Pair, PowerLine, ++ Key topic for FPI integration in active networks: SCADA-integration: IEC870, DNP3

14 Summary and Conclusions: Remote FPIs increase operational efficiency: Reduce localization and sectionalisation time Reduce need for manual fault tracking. RFPIs Redundancy (Easier localization) Less crew intensive Less time consuming Enable active networks and cost efficient remote measurements also in DG/meshed networks.

15 Thank you for your attention! Questions or comments?

16

17 Extra slides

18 Directonal Fault Detection Transient phase comparison for earthfault detection Uo Io

19 TheIntelligent Fault CurentIndicator Th ei nt eligent Fa ult Current Indi cator Prague, 8-11 June 2009 Detection of downed/broken conductors FEEDING DIRECTION FUSE SURGE ARRESTOR DOWNED CONDUCTOR DETECTOR WITH COMM. NO DETECTION FAULT LOCATION BACKFED FAULT FROM DISTRIBUTION TRANSFORMER TRANSFORMER 230V DETECTION Relay Protection LT 3200 Backfed Fault Rarely Yes Broken Loops No Yes Ice/pavement etc. No Yes Stolen cond. No Yes Blown HV-fuses No Yes

20 NORT ROLL GA TEW A Y RUN MS G2 TX /RX UART RESET NORT ROLL GA TEW A Y RUN MS G2 TX /RX UART RESET Prague, 8-11 June 2009 Detection of downed conductors Activated detector SCADA operating centre COMTROLL Communication unit Remote switch Downed or broken conductor

21 Cross country faults OC CCF EF Transm ission system 60/20 kv FPIs are able to differentiate between Overcurrents (OC) and Cross-country faults (CCF) by means of zero-sequence measurements. With directional EF-detection both locations can be pinpointed.

22 Cross country faults FPIs are able to differentiate between Overcurrents (OC) and Cross-country faults (CCF) by means of zero-sequence measurements. With directional EF-detection both locations can be pinpointed.

23 FPI retrofit examples

24 FPI Factory mounted examples

25 GSM/GPRS-enabled FPIs NetTroll SCADA System GPRS RTU Short Range Radio Collector GSM Gateway GSM Data / SMS / GPRS FPI GSM Modem Alarms