SETTING OF TARGETS FOR CONTINUITY OF SUPPLY THROUGH BENCHMARKING

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SETTING OF TARGETS FOR CONTINUITY OF SUPPLY
THROUGH BENCHMARKING

• DOUGLAS J.A.K. and CASTRO SAYAS F.
• PB Power Ltd. - United Kingdom

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RELIABILITY INDICES

• The principal reliability indices (SAIFI, SAIDI,
  CAIDI) and treatment thereto differ between
  countries
• duration of long interruptions exceeds
• 1 minute (Australia, New Zealand)
• 3 minutes (Europe EN50160)
• 5 minutes (IEEE P13662000)
• selective exclusion of categories of
  interruptions (severe weather, planned
  interruptions, transmission interruptions)

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Exclusions (examples)

• Great Britain - Exceptional events (severe
  weather) may be excluded from penalties under the
  Information and Incentives Programme (IIP),
  depending on
• impact of event and its predictability
• network design and maintenance and
• actions taken by company to deal with the event.
• Victoria, Australia
• Excludes transmission failures, widespread rare
  events in calculation of incentive/penalty
  service term (S).

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New South Wales, AustraliaDifferent measures of
supply interruption indices
Measure Description
Overall All interruptions, including transmission interruptions.
Raw All interruptions less transmission interruptions.
Standard Raw, less interruptions due to major natural events and less than 1 minute interruptions.
Modified Standard Standard, less all planned interruptions
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FREQUENCY OF INTERRUPTIONS versus LOAD DENSITY
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DURATION OF INTERRUPTIONS versus LOAD DENSITY
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SAIFI versus PROPORTION OF UNDERGROUND CABLES
GREAT BRITAIN
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SAIDI versus PROPORTION OF UNDERGROUND CABLES
GREAT BRITAIN
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CAIDI versus PROPORTION OF UNDERGROUND CABLES
GREAT BRITAIN
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CUSTOMER DENSITY versus UNDERGROUNDING GREAT
BRITAIN
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STATUS OF COMPARISON OF CONTINUITY PERFORMANCE IN
GREAT BRITAIN

• IIP and the Distribution Price Control Review
• Ofgem, February 2003, " comparisons of
  Companies performance used to set the targets at
  the last price control (in 1999) were not
  sufficiently robust "
• Ofgem, April 2003, intends to
• review the overall package of output delivery
  incentives and
• undertake a customer survey to inform a review of
  performance standards and the IIP

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Ofgem and DNOsComparing Quality of Supply
Working Group
SAIDI customer minutes
customers
minutes lost x km of network
km of network customers
minutes lost x km of network x No. of circuits
km of network No. of circuits customers
(length/circuit) (1/"customer sparsity")
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Ofgem and Distribution Network Operators
(DNOs)Comparing Quality of Supply Working Group

• Disaggregates MV circuits by grouping similar MV
  circuits on the basis of three physical
  parameters
• percentage of overhead line,
• circuit length, and
• customers per circuit ("customer sparsity")
• to identify
• key drivers in variance in performance between
  DNOs and
• possible actions for closure of differences in
  performance between DNOs.

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REFERENCE NETWORK MODEL(UMIST)

• enables the continuity performance of an MV
  radial network to be modelled using a number of
  generic reference circuits
• incorporates a process for the disaggregation of
  a very large number of actual circuits into a
  limited number of reference circuits, based on
  key parameters, and
• enables benchmarking and target setting and hence
  the modelling of strategic programmes of
  improvements to be undertaken in a comprehensive
  and systematic manner