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What are the aspects ofWhat are the aspects of
Power QualityPower Quality
Management ?Management ?
Overview
An appropriate regulatory framework
Extensive PQ and interruption monitoring programs
National PQ standards
Customer PQ contracts
Customer PQ forums
Transmission/Distribution PQ contracts
Long-term sustainability measures
Short-term business targets
Network technical solutions Behind-the-meter solutions
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How does a power qualityHow does a power quality
database form a businessdatabase form a business
tool ?tool ?
Monitoring Program
Since 1998 most TX/DX (114) supply points (mainly
132kV, and 88kV) are permanently monitored.
The following 10-minute parameters for all three
phases are stored on a national Database (together
with data from about 400 Distribution monitors):
Voltage magnitude
Unbalance
Harmonics (3, 5, 7,11, and 13th harmonics)
THD Dips on the individual phases are also stored for all
Tx/Dx sites. These are matched to faults on the
network.
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Eskom Statistics
Since 1998
Registered users (>200)
10 min values (> 1 billion)
Dips (> 500,000)
Monitoring Program Instruments downloaded daily or interrogated
Various security levels (administration, users)
Audit
Instrument connectivity / tracking
Daily summation of data
Link events with causes (e.g. line faults)
Specific contractual limits flagged
Web access to customers
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Central Server/Environment
DataLoaders
LoaderManager
Oracle
DataStore
Oracle
Data
Warehouse
Summator
DataView
Area A / Area B / ...
Data Retrieval/
Placement
Eskom Wide
Reports
DRPArchiving
SecurityAuditing
Db link
Other
Systems InterfaceManager
LimitManager
ODBC
Data
Manager
DataConvertors
Reports
PQ Database
POWER QUALITY SHORT COURSEPOWER QUALITY SHORT COURSEVoltage Dips: Utility ManagementVoltage Dips: Utility Management
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Business Features
Security
Audit
Integration
Instrument connectivity / tracking
Daily summation
Link events with causes
Specific contractual limits flagged
Customer PQ Information
Web access to closest monitored sites (key customers)
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What is an OperationalWhat is an Operational
Sustainability Index ?Sustainability Index ?
Sustainability index
Aims:
Assurance that plant is not abused for
the purpose of short-term benefits
Ensure companys long-term success
as a viable business
Provide adequate warning of negative
trends
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Sustainability Index
PRINCIPLES BEHIND ALARM ANDSTANDARD SETTINGPlanning figure
Alarm
Standard
Target
Ceiling
B K-I E T CImprovement direction
F
Increasing score loss
200:1 (99.5%)
5:1 (80%)
1:1 (50%)
20:1 (95%)
Impossible Best Ever Benchmarked Stretch Expected Slack
Target Appraisal
Aim: To provide executive management with a
view on the targets set by the individual line
groups
50%20%
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Sustainability IndexMeasure Weight Jun-03 Jul-03 YEP
Overall Score90.97 90.97 90.70
Generation
Energy Availability Factor ( Availabilty) 6.10 Alarm Alarm Alarm
Unplanned Capability Loss Factor (Reliability) 6.10 Score= 66% S core= 66% S core= 66%
Unplanned Automatic Grid Separations (Reliability) 6.10 OK OK OK
Long Term Plant Health (Health) 6.10 OK OK OK
Nuclear Performance (Health) 6.10 Alarm Alarm Alarm
Low Frequency Incidents (Generation Contribution) 2.75 OK OK OK
Transmission
Transmission Availability 6.10 Sc or e= 89 % Sc ore = 8 9% Sc or e= 89 %
Transmission Reliability 9.76 OK OK OK
Transmission Disturbance 2.89 OK OK OK
Transmission Waveform 1.73 OK OK OK
Transmission Customer 2.25 Alarm OK Alarm
Distribution
Distribution Reliability 2.11 Alarm Alarm OK
Distribution Disturbance 4.40 OK OK Alarm
Distribution Waveform 3.60 OK OK OK
Distribution Customer 15.63 Sc or e= 83 % Sc ore = 8 3% Sc or e= 82 %
Common
NER Compliance 6.10 Alarm Alarm Alarm
Conventional Safety 6.10 Sc or e= 40 % Sc ore = 4 0% Sc or e= 40 %
Environmental 6.10 Alarm OK OK
Experience: Voltage Magnitude In 2000 relays on PQ instruments at T&D interfaces
used to send alarms based on 10-minute values to
National Control
Together with automatic tap changer optimisation
resulted in a dramatic improvement in performance
Upper limit
Lower limit
00h00
.
X (alarm on)
Y (alarm off)
Time
00h10
00h20
00h30
00h40
Voltage
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Technical InterventionsPercentage of sites exceeding voltage magnitude
objectives at T&D interface points
17.4
14.3
7.15.4
3.63.6
21.4 21.4
18.8 19.7
54
1
6
11
16
21
26
Feb-00
Mar-00Ap
r-00
May-0
0
Jun-00Jul-00Au
g-00Se
p-00Oc
t-00No
v-00De
c-00Jan-01
2000/2001
%
12 MMI
SI Standard
SI Alarm
Sustainability IndexTechnical Audit Department
Transmission - Quality of SupplyQOS - Voltage Regulation
15.9
17
6.2
4.5 4.5
16.2
4
5
0
5
10
15
20
1997 1998 1999 2000 2001 2002 2003 2004 2005
%S
ites>NER/SALimit
Actuals Standard Alarm NER, 1999 - 2002 TBP congruant 2003 TBP
2002 Actual - Aug YEP
Pre-2001 discounting not applied.
Month by month information based on new rules not available.
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Customer rights
Contact within 2 working days If measurements required, free for first 2 weeks
If not conclusive, IR process (e.g. problemgone)
If solution is practical and economic, Eskom willput in place actions to resolve
Report within 6 weeks, otherwise regularfeedback
NCR process to NER
Provision of investigation number
Managed contract: install a meter at customercost, and a monthly cost
What are typicalWhat are typical
equipment failureequipment failure
statistics for MV and LVstatistics for MV and LV
customers ?customers ?
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MV Power Quality and Reliability
PICPIC
CC-MaximoCC-Maximo
OIDs/NEPSOIDs/NEPS
MaximoMaximo
12 months
13,000 claims /
complaints
call centre
rural/urban
connection
detail (text)
Direct ContactDirect Contact
MV Power Quality and Reliability
0
50
100
150
200
250
300
Number
Bellville
Bloem
fontein
Mkondeni
Johannesburg
No
rthEast
N
orthern
S
outhern
TOTAL CLAIMS LOGGED ON PIC
1 Jul 2002 - 30 Jun 2003SUPPLY-RELATED CLAIMS LOGGED ON PIC
0
5
10
15
20
25
30
35
40
45
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
2002/2003
Number
Bellville
Bloemfontein
Mkondeni
Johannesburg
NorthEast
Northern
Southern
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MV Power Quality and Reliability
0
20
40
60
80
100
120
140
160
180
Number
TV's
Fridges
Computers
Pumps
Radio's
Motors
CD/DVD's
HIFI's
Microwaves
VCR's
Kettles
Irons
Faxmachines
Lightbulbs
LOSSES REGISTERED ON PIC: JULY 2002-JUNE 2003
(Excluding faxes and letters referred to in PIC)
Power Quality ContractsPower Quality Contracts
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Contractual PQ Relationships
EskomTransmission
Eskom
Customers
T&D
Interfaces
Formal Internal
T&D agreements
Eskom
Distribution
InternationalConnections
Re-distributors
Re-distributor
Customers
Customer
Interfaces
Formal Supply
Contracts
Contracts with re-distributors supplied from the transmission system
are developed and managed by Eskom Distribution.
Contractual relationships
T&D agreements at internal supply points and supply
contracts at bulk delivery points are based on
The requirements of NRS-048
Contracts with customers supplied at HV or EHV
Historical performance data
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Customer Contracts
Eskom PQ performance defined Customer disturbance limits
Based on NRS 048:2
Quality Options
Standard
Managed
(Network Specific)
Premium power
Standard Contract:
This will make reference to NRS-048, i.e.that Eskom as a company will meet NERrequirements
This includes the 5% allowable exceedances
This is predominantly for customers who willnot be concerned with voltage dips
No cost implications to the customer
Power Quality Contract Options
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Power Quality Service Contract:
Eskom will provide:
historic dip performance
on-going dip performance information
location of faults
causes of faults where known
any action plans to improve the dipperformance
The customer could pay for this service andthe meter
This information will be published on thewebsite
Power Quality Contract Options
Network Performance Contract:
This includes the Power Quality ServiceContract option
Contracted limits based on valid dipperformance data
At least 5 years of data with an instrumentavailability of at least 300 days per year
This contract is usually only entered into aftera period that the Power Quality ServiceContract has been in place
Power Quality Contract Options
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Premium Power Contract:
Eskom will provide a guaranteed level ofquality that meets the customers specificneeds
The full cost of the solution, maintenancecosts, service costs, and risk costs will becharged to the customer
This contract can be entered into at anytime with a customer
Power Quality Contract Options
How do internationalHow do international
utilities view PQutilities view PQ
contracts ?contracts ?
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Contracting
POWER QUALITY CONTRACTS
Degree of Interest in Im plementat ion(average non-exclus ive weight ing)
- Standard
- Netw ork Specif ic
- Premium Power
LOW MEDIUM HIGH
Survey: 27 Utilities
Formal program: active implementation
Informal program: ad-hoc
implementation
Under consideration: presently
considering implementation
No program: no program and no
intention to implement such a program
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Survey: 27 Utilities
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Percentage of
Utilities
Contracts Custom Power
UTILITY POWER QUALITY SERVICES
Formal Program
Informal Program
Under Consideration
No
Survey: 27 Utilities
PQ contracting: impacted by regulatory
conditions, standards for benchmarking,
and litigation concerns in the US
Custom power programs: in all most all
cases the customer is required to pay for
the solutions
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CASE STUDY:CASE STUDY:
EDF Quality PlanEDF Quality Plan
Case Study: EDF Contracts
Contracts put in place first with 6000 MV customers,
and then all MV customers (>250 kW).
Reflected the improvement in the guaranteed
individual customer interruption performance
statistics over a 5-year improvement plan.
Called the Emeraulde Contract.
Reflects the utilitys commitment to power quality
and applies the principle of offering financial
compensation based on overall damages incurred if
one of the agreed limits is exceeded.
These limits determined at national level.
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Case Study: EDF ContractsCustomer
categories
Interruptions Area
categories
No.
Customers supply All interruptions 1 36
with two feeders > 1 s 2 13
and automatic 3 6
change over 4 4
16
Sustained interruptions 2 3
Other customers > 3 min 3 3
4 2
Momentary interruptions1
30
1s < duration
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How are limits for largeHow are limits for large
customers negotiated ?customers negotiated ?
STAGE 2 Specificcontractual limits
Load emission evaluatedw.r.t. total emission fromother loads
(standard procedure)
exceedsStage 1
STAGE 3 Specificcontractual limitsand specifiedconditions
Load emission evaluatedw.r.t. total emission from
other loads and specificlocal conditions
(special study)
exceedsStage 2
Design mitigationstrategy to reduce loademission or networksensitivity
exceedsStage 3
Standardcontractualclauses
Load too small toimpact PCC levels
START
(standard tables)STAGE 1
Defining plant emission levels
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Voltage QualityVoltage Quality
ALLOCATIONALLOCATION ((LIMITLIMIT -- BACKGROUNDBACKGROUND).).MVAMVA11
MVAMVAii
}
}}
STAGE 2 allocation
Concession based on technical
motivation (no additional risk)
Concession with risk transferred
to customerSTAGE 3
STAGE 2
Contractual risk management
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Contractual risk managementContractual risk management
Examples of technically justified concessions: large non-flicker-generating load at PCC
high HV/LV attenuation ratios
Examples of risk transferred
future emission-producing loads
generator availability / nuclear station future
long-term equipment outages
customer complaints (if above standard)
concessions by the NER to temporarily
allow higher levels