1J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

SETTING OF TARGETS FOR CONTINUITY OF SUPPLY

THROUGH BENCHMARKING

DOUGLAS J.A.K. and CASTRO SAYAS F.

PB Power Ltd. - United Kingdom

2J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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 P1366–2000)

• selective exclusion of categories of interruptions (severe weather, planned interruptions, transmission interruptions)

3J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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).

4J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

New South Wales, AustraliaDifferent measures of supply interruption indicesMeasure 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

5J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

FREQUENCY OF INTERRUPTIONS versus LOAD DENSITY

y = 105.9x-0.2

0

100

200

300

400

500

0.001 0.010 0.100 1.000 10.000 100.000

GWh/km²

Inte

rru

ptio

ns

per

year

/100

cu

stom

ers

6J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

DURATION OF INTERRUPTIONS versus LOAD DENSITY

y = 102.8x-0.2

0

100

200

300

400

500

0.001 0.010 0.100 1.000 10.000 100.000

GWh/km²

Ave

rage

cus

tom

er m

inut

es lo

st p

er y

ear

7J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

SAIFI versus PROPORTION OF UNDERGROUND CABLES – GREAT BRITAIN

R2 = 0.58

1

10

100

1000

0% 20% 40% 60% 80% 100%

% MV network underground

Cu

sto

mer

inte

rru

pti

on

s (S

AIF

I) p

er

100

cust

om

ers

8J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

SAIDI versus PROPORTION OF UNDERGROUND CABLES – GREAT BRITAIN

R2 = 0.45

1

10

100

1000

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

% MV network underground

Cu

sto

me

r m

inu

tes

lo

st

(SA

IDI)

9J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

CAIDI versus PROPORTION OF UNDERGROUND CABLES – GREAT BRITAIN

0

100

200

300

400

500

0% 20% 40% 60% 80% 100%

% MV network underground

CA

IDI (

SA

IDI /

SA

IFI)

m

inu

tes/

inte

rru

pti

on

10J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

CUSTOMER DENSITY versus UNDERGROUNDING – GREAT BRITAIN

R2 = 0.84

1

10

100

1000

0% 20% 40% 60% 80% 100%

% MV network underground

Cu

sto

mer

s p

er M

V k

m

11J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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

12J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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")

13J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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.

14J A K Douglas UK Session ALPHA2 – Block 4

Barcelona 12-15 May 2003

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