CABLE ASSET MANAGEMENT PREDICT WITH CERTAINTY. Kuljit Singh BSc Honours MIEE(IET,UK) 5 June 2014

Transcription

1 CABLE ASSET MANAGEMENT PREDICT WITH CERTAINTY Kuljit Singh BSc Honours MIEE(IET,UK) 5 June 2014

2 Definitions International Workshop 2014 DTS: Distributed Temperature Sensor DCR: Dynamic Cable Ratings ( or RTTR: Real Time Thermal Ratings)

3 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

4 To prevent failures like these New Zealand 1998: Thermal overheating due to dry summer caused 4 power cables to central business district to fail. Power outages for 5 months more than $200m of damage & lost revenues London, UK 1962: Cable failure in the UK on the Belvedere Sydenham circuit in the Summer due to soil dry out

5 Power Applications International Workshop 2014 Overhead Cables Subsea Cables Buried Cables Transformer Cable Tunnels

6 Buried Power Cable Cables are rated to thermal calculations based on: Load on cable Thermodynamic properties of cable Thermal Dissipation of Surrounding Environment Fibre optic sensor Power cable in trefoil configuration Surrounding soil heated by power cable

7 Buried Power Cable Factors which can lead to lower heat dissipation and cause cable over heating: Unknown/changing soil thermal resistivity Dry Weather conditions Surface effects Shallow road crossings Microbes in soil (caused by decomposition) Nearby cables & pipelines Faults in cables/connectors DTS removes uncertainty & improves safety

8 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

9 OTDR Optical Time Domain Reflectometry Simplicity of measurement similar to time of flight principle used for RADAR Standard multi-mode optical fibre T 1 T 2 T 3 T 4. Backscattered light provides measurement point every 1m 1m pulse of light T 9,995 T 9,996 T 9,997 T 9,998 T 9,999

10 The Technology Principles Spectroscope Laser Pulse Laser pulse Backscatter Rayleigh Optic fiber Spectrum Analyzer Anti-Stokes Brillouin Brillouin Stokes Raman Raman DTS DTS instruments measure the change in reflected light against time. Nature of optical reflections change with temperature, strain and pressure Measure all points along a fibre - distributed.

11 OTDR - Optical Time Domain Reflectometry Simple principle similar to time of flight (Radar) 1m 2m 3m 1/100,000 2/100,000 3/100,000 seconds = 1m 2m 3m

12 Dynamic Cable Rating System To provide the power system operator with cable ratings based in on real-time measurements and a thermal model. Using a real-time software system taking inputs from the Power System and Distributed Temperature Sensor (DTS) Outputs for user are: Real time power rating (e.g. maximum continuous load cable can sustain without exceeding the thermal rating) Emergency load rating: (e.g. maximum load cable can sustain for a defined period of time 24 hours, 6 hours, 20 minutes) Seamless system integration (e.g SCADA, Ventilation, Relay)

13 Cable Monitoring System Architecture

14 Thermal Model used for DCR Based on Electra 87 as recommended in IEC60287 & Enhancements Unconditionally stable Crank-Nicolson numerical iteration method Excerpts from CIGRE 87

15 Dynamic Cable Rating for various layouts Adaptable to environment Buried cables Cables in air Multiple cables Adaptable to cable geometry

16 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies (1) 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

17 Case Study (1): Buried Cable Monitoring 33 kv Buried Cable in Trefoil Formation 4km in length

18 Data Analysis over 24 hours Temperature higher at road crossings Temperature cooler at river crossing Temperature at peak loading still well within specifications

19 Dynamic Cable Rating - Screenshots

20 Network Optimisation using of DTS Sample calculation using 110 kv cable rated to 50 MW Price of power to customer* = $0.11 / kwh Typical cable loading =40% Number of peak hours per day = 3 If cable loading is increased by 5% from(e.g. from 40 to 45%) Additional revenue per year = $300,000

21 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies (2) 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

22 220kV Cable Route total route 38.5km 4 major different sections (OH bridge/direct buried/tunnel) Two Cables Manu.

23 220kV Cable Route total route 38.5km

24 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

25 Subsea Cables International Workshop 2014 Overhead Cables Subsea Cables Buried Cables Cable Tunnels

26 Subsea Cables International Workshop 2014 Wind farms, country inter-connectors & Off shore platforms Similar to buried transmission cables except: No redundancy => more critical to monitor Longer distances => DTS performance essential Very difficult to access => important to maximize lifetime

27 Off Shore Wind Farm Cables <120km

28 Cable Tunnels International Workshop 2014 Overhead Cables Subsea Cables Buried Cables Cable Tunnels

29 Cable Tunnel Management Provides 3 monitoring option 1. Fire Detection: Cable installed in tunnel ceiling 2. Ventilation Control: Feedback loop to ventilation system 3. Hot Spot/Cable rating: Fibre attached to power cable Ventilation fan Power cable Data output to: -Tunnel Ventilation Control - Fire detection system - Cable monitoring

30 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

31 Multimode vs. Single-mode Myth: Single-mode is better than Multimode > 10km Telecoms standard Multimode for short distance Single-mode for long distance Telecoms measurements sensitive to modal dispersion which is larger effect in multimode

32 Multimode vs. Single-mode Multimode = a lot more power in the fibre Losses at 1550nm very similar Single-mode = 0.2 db/km Multimode = 0.3 db/km

33 Multimode vs. Single-mode Comparison of Sentinel DTS XR multimode versus single-mode performance for a 30 minute measurement

34 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

35 DTS Product Range Series Range Performance Operating Temp Channels Max Power Spatial Resolution Typical applications Sentinel DTS-LR Sentinel DTS-XR (Incl Single-mode) 10km 12km 20km 30km <1ºC +5 to +40 ºC Up to W 1m 12km 2m 30km Power, Dam, Pipeline Sentinel DTS-XXR 60km 5m >30km Halo DTS 4km <0.1ºC +0 to +40 ºC 4 built in 40-50W 2m Fire, Power, Environmental Oryx+ SR DTS 5km <0.1ºC -40 to +65 ºC 4 built-in 18W 1m Oryx+ XR DTS 12km 30km <0.01ºC -5 to +65 ºC 30W 1m 2m Pipeline, Dam, Environmental

36 Contents 1) Issues for Buried Underground Cables 2) Technology Principles and cable thermal models 3) Case Studies 4) Further applications 5) Performance comparison of MMF vs. SMF 6) Sensornet Product Range 7) Summary

37 Summary International Workshop 2014

38 KNOWLEDGE = POWER Obrigado Visit us at Booth No. 5