Matthieu Michel

1
INNOVATIVE ASSET MANAGEMENT AND TARGETED
INVESTMENTS USING ONLINEPARTIAL DISCHARGE
MONITORING MAPPING TECHNIQUES
Matthieu Michel May 2007
2
What are the problems ?

• EDF Energy underground MV network 38 000Km
• Current replacement rate too low
• We dont know what cable to target

3
Technology objectives

• Improve Quality of supply
• Gather real-time information on the condition of
  the network
• Target replacement/refurbishment programmes

4
History latest developments (1/2)
2007
2003
2001
1999

• Automated downloads and analysis
• Web interface

5
Some results (1/2)
Lead sheath joint failure
6
Some results (2/2)
Cable replacement
Cable replacement and analysis
7
What cannot be done ?

• Detect and Locate all the faults
• Faults too far
• Earthing not suitable
• Some faults do not generate partial discharge
• Predict time of failures

8
DEPLOYMENT AND BENEFITS
9
Methodology
Database / Fault analysis
ANALYSIS
Spot testing
IDENTIFICATION
MONITORING
LOCATION
10
Deployment (1/2)
Detection Zone
Network diagram showing the Primary substation
network being monitored
Network to Investigate
Partial Discharge Monitoring Equipment
11
Deployment (2/2)
Network diagram showing a remote part of the
network being monitored
Detection Zone
Network to Investigate
12
Technology benefits (1/2)

• Financial
• Reduction in operational expenditure Cost
  savings of repairing faults
• Better control of capital expenditure
  Targeted cable replacements
• Deferment of capital expenditure Avoiding
  premature replacement
• Quality of supply
• Reduction of the Customer Interruptions
  Avoiding faults
• Reduction in multiple interruptions More
  accurate first diagnostic

13
Technology benefits (2/2)

• Environmental
• Reduction of environmental impact and
  disruptions Organised cable replacement
  programme rather than emergency opening notices
• Operational
• Versatile technology Multiple asset monitoring
  (Cable, switchgear, etc)
• Development of a robust cable replacement
  strategy

14
Deployment strategies (1/3) Large-scale
deployment

• Cost 30M (40 of primary substations equipped
  and 2 equipment along each feeder)

Estimation on EDF Energy Network UK regulatory
regime
Long Payback period
15
Deployment strategies (2/3) Surgical deployment

• Cost Negligible

Estimation on EDF Energy Network UK regulatory
regime
Very limited impact
16
Deployment strategies (3/3) Targeted deployment

• Cost 7.5M (10 of primary substations
  equipped and 2 equipment along each feeder)

Estimation on EDF Energy Network UK regulatory
regime
Best cost / benefit solution
17
Alternatives

• No deployment Increasing number of faults
  operational cost
• Increase Automation
• Necessary but would not reduce the number of
  faults
• Does not help the identification of degrading
  sections of network
• Off-line testing only
• Need for outages ? increases the risks on the
  network
• 20 years to cover the entire EDF Energy
  underground cable network
• Large-scale cable replacement impractical and
  very expensive

18
Conclusions

• Technology can deliver benefits now
• Some faults can be detected and located before
  they occur
• Target cable replacement
• Distributed equipment can be installed on remote
  parts of the network
• EDF Energy
• - Trial deployment Validate the impact of
  targeted deployment
• - Control system integration
• - Developed cable replacement strategy
• - Research Fault identification and estimation
  of Time to failure