UNITEN ARSEPE 08 L2
Transcript of UNITEN ARSEPE 08 L2
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DISTRIBUTION
SYSTEM PLANNING:
PRINCIPLES ,
CRITERIA & METHODS,
ISSUES & WAY
FORWARD
1
FORWARD
ILSAS
By:
Halim Osman
General ManagerAsset Management
TNB Distribution
PRESENTATION OUTLINE
� Distribution Business & ESI
� Regulatory Framework- Standards, Codes, Acts & License
� Performance Standards
� Design Principles/ Considerations/Criteria
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� Design Principles/ Considerations/Criteria
� Issues & Challenges in Distribution Planning
� Evolution of Planning Methodologies
� Summary & Conclusions
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DISTRIBUTION
BUSINESS &
ELECTRICITY SUPPLY
INDUSTRY
3
INDUSTRY
ILSAS
TYPICAL INDUSTRY STRUCTURE & PARTIES
G
Generators
DG
Consumers
DG
External Parties
Directly Connected Customers
Directly Connected Customers
Transmission
THE GRID
SYSTEM
External Parties
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G
GMain InterconnectedTransmission System(500kV and 275kV)
Transmission Systemat 132kV and 66kV
G
Distribution Systemat 33kV and below
Consumers
EmbeddedDistribution
DG
NetworkOperators
GNetwork
OperatorsG
GenerationSystem
TransmissionSystem
DistributionSystem
TOTAL POWER
SYSTEM
Grid Code Distribution Code
DISTRIBUTION NETWORK BUSINESS
Grid System – Grid System Operator (GSO)
Co
nsu
mers
DG
Distributor
MV ConsumersWith DG
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Distributor
MVConsumers
LVConsumers
DG
DistributedGenerator
MV
C
on
su
mers
EmbeddedDistributor
DG
ESI ON DISTRIBUTION BUSIENSS
• MORE PLAYERS THUS REQUIRING CONSISTENT,
TRANSPARENT, GUIDED ACTIONS BY MANY PARTIES TO
ENSURE SYSTEM PERFORMANCE – SAFETY, ADEQUACY,
RELIABILITY & ECONOMICS OF SYSTEMS.
• NEEDS FOR CODES, STANDARDS & COMPLIANCE
• DSITRIBUTION BUSINESS – REGULATED MONOPOLY
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• DSITRIBUTION BUSINESS – REGULATED MONOPOLY
• RELIABILITY PERFORMANCE MONITORING & REPORTING
• INDUSTRY TRENDS IN PERFORMANCE STANDARDS
• RELIABILITY LIMITS /SEGMENTED TO RURAL & URBAN
• REPETITIVE FAULTS/CUSTOMERS AFFECTED
• IMPOSITION OF GUARANTEED STANDARD OF PERFORMANCE(GSOP)
ILSAS
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REGULATORY
FRAMEWORK - CODES,
ACTS, STANDARDS
7ILSAS
G G
Main Interconnected Transmission System
Generation
Transmission
GenerationReliability Standards
TransmissionReliability
Sufficient generation capacityand connections to deliver fullgeneration output for normal and Specific contingencies
GR
ID C
OD
E
Sufficient transmission capacity to meet demand for specified contingencies
Meeting standards performance limits
Criteria for planning, designingand operating of transmission system to meet reliability and
TOTALPOWERSYSTEMS
Transmission System
Reliability Standards
Relationship between Systems, Standards, and Codes
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Transmission radial networkand demand points
Distribution System
Embedded Distribution
Customers
DG
DG
Distribution
Reliability Standards
TransmissionPower Quality
Standards
system to meet reliability and power quality standards
Sufficient transformer capacity to meet demand
Power quality limits atinterfaces
Criteria for planning, designingand operating of distribution
system to meet supply security
and power quality standards
STANDARDS CODES
DIS
TR
IBU
TIO
N C
OD
E
Distribution Supply Security and Power Quality StandardsSYSTEMS
EXAMPLE OF ACT (‘EXAMPLE OF ACT (‘AKTAAKTA’)’)
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Cover Page First PageILSAS
EXAMPLE OF RULES (‘EXAMPLE OF RULES (‘PERATURANPERATURAN’)’)
Contoh daripada
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Contoh daripada Akta Bekalan Elektrik 1990
ILSAS
EXAMPLE OF INDUSTRY CODEEXAMPLE OF INDUSTRY CODE
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Cover Page of Distribution Code
Contents Page of Distribution Code
ILSAS
PERFORMANCE STANDARDS ~ SUPPLY SECURITYPERFORMANCE STANDARDS ~ SUPPLY SECURITY
1. Normal MV Breakdown:
a.) For single circuit outage (except busbar)
• 50% restoration within 2 hours (syarat 15)
• restoration time 4 hours
b.) For rural areas or MD < 1MW
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b.) For rural areas or MD < 1MW
– restoration time ≤ 24 hours
2. Normal LV Breakdown:
– restoration time ≤ 24 hours
3. Extra-ordinary Breakdown (Force De Majoure):
– restoration time may be > 24 hours
Reference : ‘Distribution Planning Code’ 5.4.2.3
ILSAS
� Voltage Regulation (Normal Condition):
� MV of 6.6/11/22/33kV : ±±±±5% of nominal voltage
� LV of 240V & 415V : +5% & -10% of nominal voltage
PERFORMANCE STANDARDPERFORMANCE STANDARD-- VOLTAGE LIMITS VOLTAGE LIMITS
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� Voltage Regulation (Contingency Condition):
� MV : ±±±±10% of nominal voltage
� LV : ±±±±10% of nominal voltage
ILSAS
� Frequency Regulation (Normal Condition):
� System Frequency : ±±±±1% of nominal value of 50Hz
� Frequency Regulation (Exceptional Circumstances):
PERFORMANCE STANDARDPERFORMANCE STANDARD-- FREQUENCY LIMITSFREQUENCY LIMITS
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� Frequency Regulation (Exceptional Circumstances):
� System Frequency : within 47Hz & 52 Hz
ILSAS
PERFORMANCE STANDARD- SECURITY
LEVELS
LEVEL RESTORATION TIME DESCRIPTION
1 Less than 5 secondsCustomer who specially request for theservice
Selected urban areas, industrial areas,
15
2 Less than 15 minutesSelected urban areas, industrial areas,hospitals & places of nationalimportance
3 Less than 4 hoursAll areas except for rural areas & anyareas or circuit with group peakdemand of < 1MW
4 Less than 1 dayRural area having total demand < 1MW
� System Average Interruption Duration Index
� It provides information about total average time the
customers are interrupted.
� Measures of reliability of supply
PERFORMANCE INDEX – SAIDI (1/2)
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� Measures of reliability of supply
� Records the frequency and duration of outages that
customers may experience.
� Only loss of supply exceeding 1 minute will be
counted
Average Interruption time / customer / year
dC
n
∑
PERFORMANCE INDEX – SAIDI (2/2)
SAIDI =Σ Customer Interruptions Duration
Σ No of Customer Served
(= SAIFI x CAIDI)
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N
dC
i
ii∑== 1
Where:
Ci = No of interrupted customers
di = Restoration time of each interruption event (in min)
n = No of interruption event
N = No of customers served
(= SAIFI x CAIDI)
PERFORMANCE INDEX - CAIDI
� Customer Average Interruption Duration Index
� Average time required to restore service to the averagecustomer per sustained interruption. (Average duration perinterruption)
CAIDI =Σ Customer Interruption Durations
Σ No of Customer Interrupted
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Σ No of Customer Interrupted
∑
∑
=
==n
1i
i
n
1i
ii
C
dC
Where:
Ci = No of interrupted customers
di = Restoration time of each interruption event (in min)
n = No of interruption event
� System Average Interruption Frequency Index
� Average frequency (no.) of sustained interruptions per customer.
SAIFI =Σ No of Customer Interruptions
Σ No of Customer Served
PERFORMANCE INDEX - SAIFI
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N
Cn
1i
i∑==Where:
Ci = No of interrupted customers
N = No of customers served
n = No of interruption event
SUBSTATION FIRM CAPACITY
� System must be operated below firm capacity
� Substation uses (PMU/PPU/SSU/PE)
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� Substation uses (PMU/PPU/SSU/PE)
� Uses ‘n-1’ CONCEPT
FEEDER FIRM CAPACITY & DESIGN CRITERIA (1/2)
� Feeder uses 50% loading concept
� First leg cables from PMU/PPU must be at least of size
240 mm2 3C Al XLPE or any equivalent capacity.
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� No more expansion of cable 70 mm2 Al or equivalent in the
system.
� No bottle-necks in the system.
� No spur feeder in the system except for rural domestic
load that is less than 1 MW & it is economically far away
from the source.
� Feedback should be from different source where possible.
FEEDER FIRM CAPACITY & DESIGN CRITERIA (2/2)
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� Feedback should be from different source where possible.
� MV Overhead insulated cables can be used & strung on
the same pole as LV cost-effectiveness.
� MV Overhead lines system (33kV in particular) should be
equipped with auto-recloser & sectionaliser.
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PQ STANDARDS
23
TNB’S LIMITS ON QUALITY OF SUPPLY (1/2)
1. Voltage Regulation (at Customer’s Terminal)
� LV : 415/240 V; -10% < VOLTAGE <+5%
� HV : 6.6/11/22/33 KV; -5% < VOLTAGE < +5%
2. Voltage Unbalance
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� Definition: negative phase sequence voltage, positive phase
sequence voltage
� Causes: Unbalance phase impedance and loads
� Acceptable Unbalance Voltage level is < 2%
3. Loads Affecting Supply Quality
� Steel Making ARC furnaces, rolling mills, welding equipment,
induction furnaces, power semiconductors rectifiers, computers,
railway traction, etc.
4. Harmonics
TNB’S LIMITS ON QUALITY OF SUPPLY (2/2)
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4. Harmonics
� Caused by nonlinear loads such as rectifiers and other power
semiconductors
� Acceptable limits based on the electrical regulation – MS IEC
61000 Series
CAUSES, EFFECTS & MITIGATION OF PQ EVENTS (1/2)
EVENTS CAUSES EFFECTS MITIGATION
Sags & Swells
Electromagnetic disturbance (by components failure –fault clearing, utility power system, trees, animals, lightning, 3rd party digging)
Equipment trip / process interrupted
System improvement (utility), power conditioner (customer), improvement of equipment immunity (manufacturer)
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Harmonics
Electronic gear (3Ø rectifier, power regulator, customer’s capacitive component),welders, arc furnaces, fluorescent ballasts, pc
CB tripping, unexplained fuse operation, capacitor failure, electronic equipment malfunction, flicking lights & telephone interference
Harmonic filter (shunt passive/active filter), ensure minimum harmonic emission on network design stage
CAUSES, EFFECTS & MITIGATION OF PQ EVENTS (2/2)
EVENTS CAUSES EFFECTS MITIGATION
Flickers
Mainly by huge arcing generated by furnaces in steel mill (cause health problem such as epilepsy), electronic gears, motors
Equipment trip / process interrupted
Flicker compensator
Voltage Fluctuation
Generation voltage, load end, long line-length ⇒ ↑capacitance
Ferranti effect, voltage violation, customer equipment affected
Cap bank, cable sizing, transformer tap, booster
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affectedtap, booster
Frequency Deviations
Generation Vs loadGeneration ≈ Load (freq unstable)
Maintain healthy spinning margin
Transients Animals, lightning, vegetation
PQ PERFORMANCE INDEX - SARFI
� System Average RMS Variation Frequency Index
� To show event frequency of supply interruption, voltage sag &
swell
� 2 ways of index representation:
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� 2 ways of index representation:
� SARFIX
� SARFICURVE
LimCY
SARFIX
� SARFIX ⇒ event frequency of supply interruption, voltage sag & swellunder a defined voltage level within short-duration RMS variationevents (with duration < 60s)
� Example:
a) SARFI90 = 5
5 events of voltage sag & supply interruption occur below 0.9p.u. or 90% of nominal voltage.
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p.u. or 90% of nominal voltage.
b) SARFI70 = 3
3 events of voltage sag & supply interruption occur below 0.7 p.u.or 70% of nominal voltage.
c) SARFI110 = 2
means 2 events of voltage swell occur above 1.1 p.u. or110% of nominal voltage.
LimCY
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LOADING
CRITERIA
30
LOADING CRITERIA
� Feeders
� Maximum of 50% loading of its rated capacity (for n-1
contingency).
� Transformer
� Initial / Optimum loading – 60% (Refer LV Planning Guideline)
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� Maximum loading of 90% for 24 hours Operation.
� Can load higher than 90% for cyclic loading (E.g: 100kVA ONAN
Transformer can be loaded to 1420kVA for 2 hours.
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MV NETWORK
CONFIGURATION
32
TYPICAL DISTRIBUTION SYSTEM
12 kV 132kV
33kV
33kV11kV PPU
POWER
TRANSMISSION
LINE
U/G & O/H
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12 kV 132kV
132kV 11kV
415V/240V415V/240V
PMU
POWER
STATION
PEPE
U/G & O/H
DISTRIBUTION
TYPICAL MV NETWORK
CONFIGURATION
Types of Network
Radial circuit
Mesh
Loop from same supply source
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Loop from different supply sources
Petal configuration
Twin loop
2-1-2 configuration for 33kV urban
TYPICAL NETWORK STRUCTURE
BULK SUPPLY
X
XX
XX
PMU
B/S
ON
Figure 1 (a): Parallel feeders with n - 1 elements
Network Description
Security Level
Normal State
Parallel feeders supplying bulk customer, 11kV , 22kV or 33kv
Level 1 attainable with feeder unit protection
Bus-section 'ON'
XX X X X
PMU 1PPU / CUSTOM ER PMU 2
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XX
XX
XXX
X X
X
X
X
off
B/S 1 B/S 2
Figure 1 (b). Parallel feeder w ith n - 2 elem ent
Network Description Norm al State Security Level
3 feeder into a PPU bulk custom ers switching station 2 feeder are paralle l
Breaker 'A ' is in 'OFF' position Bus section 1 and Bus section 2 are 'ON'
Level 1 estainable
XX
XX
XXX
X X
X XX
X
X
Figure 1 (c). Parallel feeders with n - 3 element
OFF
PMU 1PMU 2
PPU / CUSTOMER
A
B
OFF
TYPICAL NETWORK STRUCTURE
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Figure 1 (c). Parallel feeders with n - 3 element
Network Description Normal State Security Level
4 feeder into a PPU or bulk customer switching station 2 feeder are parallel
Breaker A and B are 'OFF' Bus section 1 and 2 are 'ON'
level attainable
Network Description Security Level
Simple - looped network from one PMU/PPU with n - 1 element
level 1 not attainable with SCADA/DA
Level 3 without SCAD/DA
Figure 2(a). Looped, configuration from one PMU with n -1 element
X
X
X
PMU 1
off
P M U 1 o f f
TYPICAL NETWORK STRUCTURE
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N e tw o r k D e s c r ip t io n N o r m a l S ta te
L o o p c o n f ig u r a t io n f r o m tw o P M U / P P U w i th n - 1 e le m e n t
L e v e l 1 n o t a t t a in a b leL e v e l 2 a t t a in a b le w i t h S C A D A /D AL e v e l 3 w i t h o u t S C A D A /D A
X
X
X
XP M U 1
P M U 2
F ig u r e 2 ( b ) . L o o p e d f r o m tw o P M U w i th n - 1 e le m e n t
o f f
PMU 1
X
X
X
XPMU 2
off
off
TYPICAL NETWORK STRUCTURE
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Network Configuration Normal State
Loop configuration from two PMU / PPU with n - 2 element
Level 2 attainable with SCADALevel 3 attainable without SCADA / DA
X
X
X
P M U 1
TYPICAL NETWORK STRUCTURE
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N e tw o rk C o n fig u ra tio n S e c u r ity L e v e l
s p u r fe e d r fro m P M U / P P U
L e v e l 4
L e v e l 1 ,2 & 3 n o t a tta in a b le
F ig u re 3 (c ) .R a d ia l C o n fig u ra tio n , n - 0 e le m e n t
X
APPLICATION GUIDE
~ SECURITY & CONTINGENCY CRITERIA (1/2)SECURITY
CONTINGENCY
CRITERION
APPLICATION
(YES/NO)
n-1 feeder element Yes
n- 1 transformer element Yes
n-1 bus-bar element No
n-1 feeder element Yes
n- 1 transformer element Yes
Looped radial feeders with
open points and fed by
same PMU or PPU source
No network control or
automation -
SCADA/DA
SCADA, Sub-station
and feeder
APPLICATION POLICY /
GUIDELINES
Parallel feeders into a
customer's bulk supply
switching station ( see fig. )
NETWORK MODELSOPERATIONAL
CONTROL
Level 1
33kV,22kV and 11kV sub-systems
for towns and sub-urban areas and
low demand density industrial
For supply schemes to bulk 11kV
& 33kV customers
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n-1 bus-bar element No
n-1 feeder element Yes
n- 1 transformer element Yes
n-1 bus-bar element Yes
n-2 feeder element Yes
n-1 transformer element Yes
n-1 bus-bar element Yes
SCADA, Sub-station
and feeder
automation
but from different secondary
buses ( see fig.)
Looped radial feeders with
open points and fed by
different PMU or PPU
source ( see fig.
Network configuration with
three (3) feeders into a PPU,
PPU supplied from two
different PMU sources ( see
fig. )
automation
SCADA, Sub-station
and feeder
automationLevel 2
33kV, 22kV and 11kV for urban
areas or similar areas (industrial
estates) with high demand intensity
and readily available reserve
capacity - PMU /PPU sources
low demand density industrial
estates
Application to 33kV network in
Penang & Klang Valley or similar
supply areas with high demand
density and readily available
reserve capacity
SECURITYCONTINGENCY
CRITERION
APPLICATION
(YES/NO)
n-1 feeder element Yes
n- 1 transformer element Yes
n-1 bus-bar element No
n-1 feeder element Yes
n- 1 transformer element Yes
n-1 bus-bar element Yes
n-2 feeder element Yes
Level 3
No SCADA/DA
Application to 33kV sub-systems Network configuration with
33kV,22kV and 11kV for lesser
important urban areas of low
demand intensity
Looped radial feeders with
open points fed by same
PMU or PPU source but
different bus-bars
No SCADA/DA
33kV, 22kV and 11kV network for
urban areas and industrial estates
with medium load density
Looped radial feeders with
open points and fed by the
different PMU sources
OPERATIONAL
CONTROL
APPLICATION POLICY /
GUIDELINESNETWORK MODELS
APPLICATION GUIDE
~ SECURITY & CONTINGENCY CRITERIA (2/2)
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n-2 feeder element Yes
n- 1 transformer element Yes
n-1 bus-bar element No
n-1 feeder element No
n- 1 transformer element Yes
n-1 bus-bar element No
No SCADA/DA
No network control or
automation
No network control or
automation
Level 4
n-1 feeder element No
n-1 feeder element Yes
Applicable to 33kV, 22kV & 11kV
feeders supplying into remote
rural areas with less than 1 MVA
Radial MV network from a
single PMU source
Generally LV networks are
operated in radial and standby
capacity through gen-sets
Radial low-voltage network
Application to 33kV sub-systems
for supply areas with high demand
density and readily available
reserve capacity - PMUs & PPUs
Network configuration with
three(3) feeders supplying
load points namely PPU with
two PMU sources
No SCADA/DA
Highly selective and customized
application to LV schemes e.g
commercial areas
Looped LV network with
open points
DESIRED 33 KV NETWORK
~ INFANT STAGE WITH 1 PMU Option for (n-
2) elemen
t
PMUPPU
PPU
PPU
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Network with (n-1) element
~ Not withstanding loss of
PMU, security level 1 & 2 is
attainable with SCADA in
place
PMUPPU
PPU
PPU
PARALLE
L
FEEDE
R
SOURCE
(n-1)
√ L1 L2
X L2 L2
DESIRED 33 KV NETWORK – 2ND STAGE WITH 2
PMU’SPPU
PMU PPUPPU
PPU
PMU
Network with (n-1) source
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Security level 1 & 2 is attainable with SCADA in place under (n-1) source contingency
PMU
PPU
PPUPPU
PPU
PMU
DESIRED 33 KV NETWORK - MATURED STAGE WITH MORE THAN 2 PMU’S
PPU PMUPPU PPU PPU
PPU PPUPMU PMU
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• Network with more than 2 sources with (n-1) concept
planned.
• Security level 1 & 2 is attainable with SCADA emplaced
under (n-1) source contingency
PPU PPUPMU PMU
PARALLEL FEEDER SOURCE (n-1)
√ L1 L2
X L2 L2Level 2 attainable with SCADA
33 KV SYSTEM DESIGN OPTIONS
TO ACHIEVE SECURITY LEVELS 2 & 1
PARALLEL FEEDER SOURCE (n-1)
√ L1 L2
X L2 L2
PMU PMUPPU PPU
PMU PMUPPU PPU
Level 1 & 2 attainable with SCADA
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PARALLEL FEEDER SOURCE
√ N/A N/A
X L2 L2
X L2 L2
PARALLEL FEEDER SOURCE (n-1)
√ L1 L2
X L2 L2
PMU PMUPPU
PMU PMUPPUPPU
Level 1 & 2 attainable with SCADA
Level 1 & 2 attainable with SCADA
Level 2 attainable with SCADA
MV NETWORK CONFIGURATION (3/4)
� Selection election of network
- Based on the reliability & security levels
� Design criteria
� Safe, fast & easy operation
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� Safe, fast & easy operation
� No overloading of remaining circuit after single cable outage
� Feedback for any single outage contingency
MV NETWORK CONFIGURATION (4/4)
� Worst requirement (Base on Syarat 15)
• 50% restoration within 2 hours
• Full restoration within 4 hours
� Loading of feeders must be less than 50% to reduce distribution
Performance Criteria
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� Loading of feeders must be less than 50% to reduce distribution
losses
� Reduce number of substations per feeder wherever possible
� Reduce number of customers per feeder
MV FEEDER CAPACITY & DESIGN CRITERIA (1/2)
� MV feeder uses 50% loading concept
� First leg cables from PMU/PPU must be at least of size 240mm2 Al XLPE
3C or any equivalent capacity
� No more expansion of cable 70mm2 Al or equivalent capacity in the
system
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� No bottle necks in the system
� No spur feeder in the system except for rural domestic load that is less
than 1MW and it is economically far away from the source
� Feedback should be from different source where possible
LooCK
� MV overhead insulated cables can be used and strung on the same
pole as LV cost effectiveness
� MV overhead bare line system (33kV in particular) should be
MV FEEDER CAPACITY & DESIGN CRITERIA (2/2)
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� MV overhead bare line system (33kV in particular) should be
equipped with auto-recloser & sectionaliser
LooCK
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DISTRIBUTION
PROTECTION
50
DISTRIBUTION PROTECTION (1/2)
� Ensure distribution network can operate within preset
requirements for the safety of the public, staff and overall
network including equipment items.
OBJECTIVES
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network including equipment items.
� Isolate faults on the network in a minimum time in order to
minimise damages
DISTRIBUTION PROTECTION (2/2)
� Radial U/G cable operated circuit (6.6, 11 & 22kV)
� Use over-current & earth-fault protection
� Radial O/H lines operated circuit (6.6, 11 & 22kV)
� Use over-current & earth-fault protection
� With auto-recloser
� Parallel circuits (Loop from same PMU/PPU)
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� Parallel circuits (Loop from same PMU/PPU)
� Use directional earth-fault & over-current
� Parallel interconnector
� Use pilot wire / fibre optic cable unit protection
� Use over-current / earth-fault as back-up
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SYSTEM FAULT
LEVEL
53
LEVEL
IMPORTANCE OF FAULT LEVELS
� Fault level in the distribution system must be identified
� To decide on fault rating of equipment.
� Magnitude of fault current depends on the infeed arrangement
and the impedance of the network configuration.
� Fault level must not exceed short circuit rating of equipment (e.g.
circuit breaker interrupting the fault current).
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� Too low fault current (long & highly loaded feeder) may unable to
operate the protective device
� Need to configure the system to reduce the system impedance.
INTRODUCTION OF FAULT LEVEL
� Analysis of power system electrical behavior under different fault
conditions
� Effects of these conditions on the power system current &
voltage.
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� Equipment rating
� Under maximum fault, the system components must be rated
such that the resultant heat can be dissipated & mechanical
forces withstand.
FAULT LEVEL IN TNB’S DISTRIBUTION SYSTEM
� Maximum fault level allowed in the distribution system
Nominal System Voltage (kV)
Rated Voltage (kV)
Fault Current (kA)
33 36 25
22 24 20
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� Withstand the rated fault current for a duration of 3 seconds.
22 24 20
11 12 20
6.6 7.2 20
0.415 1 / 0.415 31.5
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DISTRIBUTION
SYSTEM LOSSES
57
DISTRIBUTION SYSTEM LOSSES (1/2)
� Technical & non-technical losses
� Technical losses – reduce to optimum level
� Refer to “A Guidebook on Reduction of Distribution Losses”
� Non-technical losses – reduce to minimum level
� MV Losses management
� MV Feeder loading must be less than 50%.
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� MV Feeder loading must be less than 50%.
� Install shunt capacitor bank near the load.
� Optimising network (Off-point)
� Bring injection point to the load
� Load management
DISTRIBUTION SYSTEM LOSSES (2/2)
� LV losses management
� Reduce feeder loading
� Load transfer
� Use larger size conductor/cable
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� Add new feeder
� Reduce feeder length
� Reduce volt-drop losses (long lines/feeder)
� Load balancing
WHY VAr MANAGEMENT
� Voltage regulation
� Optimize distribution capacity
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� Reduce losses
� Can Cap Bank reduce harmonics ?
VAr MANAGEMENT
Cap Bank –sizing/locating - CAPO
� LV Load profiling (include Amp, Volt, VAr, Pf)
� Sub-station
� Pole top
� Customer end
� Other advantages of cap bank
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� Other advantages of cap bank
� Points to note with cap bank
� operation
� safety
� maintenance
SYSTEM STUDIES & SYSTEM STUDIES &
TECHNICAL PROPOSALTECHNICAL PROPOSAL
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Network data+ loading
(Existing & New)
Performance Diagnosis•Capacity/demand•Loading•Losses•Security•Off points•Reliability-SAIDI – (Good to have)•Fault level•Protection
DISTRIBUTION SYSTEM STUDYDISTRIBUTION SYSTEM STUDY
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Yr2
Modeling ofExisting cct,Yr0
•Protection•Others- PQ (sensitive customer)•Network regime-SCADA,EFI•Operational planning
New Standard•New network structure•Security level•Configuration Criteria•Losses
Yr1
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STEP 1: RECEIVE APPLICATION STEP 1: RECEIVE APPLICATION
FROM CONSULTANT VIA PK/PCFROM CONSULTANT VIA PK/PC
Check for: • Plan• Load details• TNB Specs compliant• Date Supply required• Expected Demand Yearly• Estimated 24hrs load profile• Site Visit
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• Site Visit
Year Yr MDMW
1999 Yr0 0.3
2000 Yr1 0.5
2001 Yr2 0.9
2002 Yr3 1.5
2003 Yr4 2.1
2004 Yr5 2.7 0
0.5
1
1.5
2
2.5
3
1999 2000 2001 2002 2003 2004
MDMW
Projected Customer Demand Growth
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STEP 2: CHECK FOR STEP 2: CHECK FOR
SUPPLY VOLTAGE LEVELSUPPLY VOLTAGE LEVEL
LOAD VOLTAGE LEVEL
< 800kW* LV
800kW to 5MW MV 11kV
5MW to 25MW MV 33kV
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5MW to 25MW MV 33kV
> 25MW MV 132kV
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STEP 3: CHOOSE DESIGN STEP 3: CHOOSE DESIGN
FORMAT FOR (nFORMAT FOR (n--1) SYSTEM1) SYSTEM
B
D E
CA
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PlanSecurity Criteria
Loading CriteriaElement
A (n-1) <50%
B (n-1) <50%
C (n-1) <50%
D (n-2) <50%
E (n-2) <50%
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%Arus Amp %Loss I^2 Act Loss0 0 0.0
10 100 0.1
20 400 0.4
30 900 0.9
40 1600 1.6
50 2500 2.5
60 3600 3.6
70 4900 4.9
80 6400 6.4
90 8100 8.1
100 10000 10.0
LOSSES IN CABLESLOSSES IN CABLES
Loss= I2R
IRON LOSSES IN CABLES
12
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100 10000 10.0
0
2
4
6
8
10
%Arus
Amp
0 10 20 30 40 50 60 70 80 90 100
%Current flow of 100%
Lo
sses
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STEP 4: FIND SITE LOCATION STEP 4: FIND SITE LOCATION
& ELECTRICAL LOCATION& ELECTRICAL LOCATION
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Site LocationSite Location
Electrical LocationElectrical Location
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STEP 5: SUPPLY ADEQUACY CHECK, STEP 5: SUPPLY ADEQUACY CHECK,
FOR CURRENT SYSTEM, WITHOUT NEW LOADFOR CURRENT SYSTEM, WITHOUT NEW LOAD
Check For 100% Feedback w/out • Current Violation ie no Overload• Voltage Violation ie no Vdrop <10%
I Vd <-10%
Limit FiguresCheck
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I1
Limit Figures
300mmp=330A
240mmp=350A
185mmp=250A
150mmp=280A
120mmp=200A
95mmp=210A
70mmp=140A
Voltage Vd <10% 9.9kV
Drop
Check
Overload
I
I1
<100%
<100%
If the system complies,proceed, if not, redesign
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STEP 6: SUPPLY ADEQUECY CHECK, STEP 6: SUPPLY ADEQUECY CHECK,
WITH NEW LOAD INJECTIONWITH NEW LOAD INJECTION
Check For 100% Feedback w/out • Current Violation ie no Overload• Voltage Violation ie no Vdrop <10%
Vd <-10%
Limit FiguresCheck
I
Inject new loadwith maximumMD in final yearwith load scalingfactor considered
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Limit Figures
300mmp=330A
240mmp=350A
185mmp=250A
150mmp=280A
120mmp=200A
95mmp=210A
70mmp=140A
Voltage Vd <10% 9.9kV
Drop
Check
Overload
I
I1
<100%
<100%If the system complies,proceed, if not, redesign
I1
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Start with load in year 5, if comply, proceed, if not go to year 4. Find in what year the system complies the standard criteria (I,V). Suggest improvement for future year yr3,yr4,y5 if any.
I
I1
Vd <-10%
STEP 7: SUPPLY ADEQUACY CHECK, STEP 7: SUPPLY ADEQUACY CHECK,
WITH NEW LOAD INJECTION & LOAD SCALINGWITH NEW LOAD INJECTION & LOAD SCALING
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Year Yr NewPE PE1 PE2 PE3 PE4 PE5 Total Growth
2005 Yr0 0.3 0.10 0.20 0.15 0.20 0.15 1.10
2006 Yr1 0.5 0.10 0.21 0.16 0.21 0.16 1.33 4%
2007 Yr2 0.9 0.11 0.22 0.16 0.22 0.16 1.77 4%
2008 Yr3 1.5 0.11 0.23 0.17 0.23 0.17 2.41 5%
2009 Yr4 2.1 0.12 0.24 0.18 0.24 0.18 3.05 5%
2010 Yr5 2.7 0.13 0.25 0.19 0.25 0.19 3.70 5%
Load in MW
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STEP 8: SECURITY LEVEL SELECTIONSTEP 8: SECURITY LEVEL SELECTION
Select security level for• The customer or• The area
Redesign to includeall features. Systemdesign to follow (n-1)source and element
Level ResTime System Design
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Level ResTime System Design
L1 5 Sec 2 dedicated parallel Cables,
Unit protection, DOC,VCB,SCADA
L2 15 Min VCB,SCADA, Unit Protection
L3 4 hr RMU + VCB
L4 1 day RMU, H Pole
L2,L3
L2,L3
L1,L2,L3
L4
L4
e.g. Penang Island
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STEP 9: LOAD FLOW ANALYSISSTEP 9: LOAD FLOW ANALYSIS
Test for single contingency (n-1)
I
I1
Vd<-10%
and
a) Contingency Criteria (Vd<-10%, I<100% for 100% Feedback)
I
I1
Vd<-10%
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I1
If comply, proceed,if not, redesign.Eg. New injection, reconductor or reconfigure.
Limit Figures 1st leg A 1st leg B OK/NOK
300mmp=330A
240mmp=350A 200A 198A OK
185mmp=250A
150mmp=280A
120mmp=200A
95mmp=210A
70mmp=140A
Voltage Vd <10% 9.9kV 10.01kV 10.02kV OK
Drop
Over Vover >5% 11.55kV No No OK
Voltage
Check
Overload
I
I1
<100%
<100%
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STEP 10: TIE OFF POINT OPTIMIZATION (TOPO)STEP 10: TIE OFF POINT OPTIMIZATION (TOPO)
Run load flow to find the lowest losses ,with different off point, or use TOPO (just an option)
Off Point % Loss Best
PE1 2.00%
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PE2 2.20%
PE3 2.40%
PE4 1.65% MinLoss
PE5 2.00%
PE6 2.30%
Choose PE4 asChoose PE4 asOFF Point.OFF Point.It gives minIt gives min
lossloss
b) Steady State (Vd <-5%,I< Cable Cap, <50%Feeder Loading, Loss<5%,pf>0.85 )
IbIa
Targeted Actual Actual
Figures Figure A Figure BCheck Limit
STEP 11: LOAD FLOW ANALYSIS (2)STEP 11: LOAD FLOW ANALYSIS (2)
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I1 I2
Vd1 Vd2
Figures Figure A Figure B
Load 50% Ia <50% 195A 105A 100A
of feeder Ib <50% 195A 100A 102A
Voltage Vd1 <-5% >10.45kV 10.91kV 10.92kV
Drop Vd2 <-5% >10.45kV 10.94kV 10.93kV
Over Vd1 >+5% <11.55kV
Voltage Vd2 >+5% <11.55kV
Losses Loss <+5% lowest 2.30% 2.30%
Power pf >0.85 1.0 0.89 0.89
Factor
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STEP 14: IDENTIFY SYSTEM LIMITATIONSTEP 14: IDENTIFY SYSTEM LIMITATION
• Increase load 4%-5% each year (based on load forecast)• Test for steady state and contingency• Find in what year, the system max• Propose system improvement for that year
Growth Total Total Loss Power
% Load(MW) Loss(kW) % O/Load Vd<-10% O/Load Vd<-10% O/Load Vd<-5% Factor
ContingencySteady State
1st legAYear
1st legB
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% Load(MW) Loss(kW) % O/Load Vd<-10% O/Load Vd<-10% O/Load Vd<-5% Factor
Yr0 2005 0 2.52 50.400 2.0 No No No No No No 0.85
Yr1 2006 4 2.62 52.416 2.0 No No No No No No 0.86
Yr2 2007 4 2.73 54.513 2.5 No No No No No No 0.86
Yr3 2008 5 2.83 56.693 2.6 No No No No No No 0.89
Yr4 2009 5 2.95 58.961 2.7 Yes No Yes No Yes Yes 0.76
Yr5 2010 5 3.07 61.319 2.7 Yes Yes Yes Yes Yes Yes 0.71
This system can withstand load growth until Yr3. Systemimprovement is required in Yr4, by laying 240mmp 11kV 1200mfrom PPU A to PE5.
Rosemi
STEP 15: ANALYSIS SUMMARYSTEP 15: ANALYSIS SUMMARY
Condition Test Yr0 Yr1 Yr2 Yr3 Yr4
Ia>50% No No No Yes Yes
Ib>50% No No No Yes Yes
I o/load No No No Yes Yes
Vd<-5% No No No Yes Yes
pf <0.85 No No No No Yes
Steady state
Yr0 Yr1 Yr2 Yr3 Yr4
Load Forecast 2.52 2.62 2.73 2.83 2.95
%Growth 0 4 4 5 5
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pf <0.85 No No No No Yes
Ia>50% No No No Yes Yes
Ib>50% No No No Yes Yes
I o/load No No No Yes Yes
Vd<-10% No No No Yes Yes
pf <0.85 No No No No Yes
Ia>50% No No No Yes Yes
Ib>50% No No No Yes Yes
I o/load No No No Yes Yes
Vd<-10% No No No Yes Yes
pf <0.85 No No No No Yes
Contingency
B
Contingency
A
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“ Add your company slogan ”
ISSUES &
CHALLENGES
78
DISTRIBUTION PLANNING & ASSET
MANAGEMENT
� DISTRIBUTION PLANNING FUNCTION – SCOPE & METHODOLOGY
TO SUPPORT ASSET MANAGEMENT OBJECTIVES – OPTIMIZE
PERFORMANCE , COST & RISKS
� DISTRIBUTION PLANNING TO UNDERSTAND EQUIPMENT
RELIABILITY PERFORMANCE, CYLCE COST OF
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RELIABILITY PERFORMANCE, CYLCE COST OF
EQUIPMENT/SYSTEMS.
� INVESTMENT ANALYSIS TO PROVIDE DEAL WITH PERFORMANCE,
COST AND RISK ASSESSMENT SO NEED FOR SUPPORTIVE
METHODOLOGIES.
LooCK
DISTRIBUTION PLANNING ISSUES(1)
� VOLTAGE SELECTION FOR HIGH GROWTH AREAS
� SECURITY STANDARDS & CONTINGENCY CRITERIA
� SERVICE LEVEL DIFFERENTIATIONS
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� DETERMINISTIC VS PROBABLISTIC CRITERIA.
� NETWORK STRUCTURE & CONFIGURATION
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DISTRIBUTION PLANNING ISSUES(2)
� PROTECTION & AUTOMATION
� EQUIPMENT DESIGN, SELECTION & STANDARDIZATION
� ASSET REPLACEMENT DECISIONS & PLANS
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� DG CONNECTIONS
� LOAD FORECASTING
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DISTRIBUTION PLANNING ISSUES(3)
� SYSTEM STUDIES: METHODS, TOOLS & DATABASES
� INVESTMENT APPRAISAL METHODS
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EVOLUTION IN
PLANNING
METHODOLOGIES
83
METHODOLOGIES
EVOLUTION IN PLANNING METHODOLOGY
RISK-BASED PLANNING
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LEAST-COST PLANNING
VALUE-BASED PLANNING
RELIABILITY-BASEDPLANNING
SUMMARY & CONCLUSIONS
� TRADITIONAL DISTRIBUTION PLANNING FUNCTION REALIGNED TO
FIT OVERALL ASSET MANAGEMENT OBJECTIVES OF UTILITIES
� DISTRIBUTION PLANNERS TO DEVELOP & APPLY
METHODOLOGIES THAT COULD EFFECTIVELY DEAL WITH
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METHODOLOGIES THAT COULD EFFECTIVELY DEAL WITH
RELIABILITY AND RISK ASSESSMENT, LIFE CYCLE COSTING FOR
ASSET DEVELOPMENT AND REPLACEMENT DECISIONS.
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SUMMARY & CONCLUSIONS
� PLANNING & DESIGN CRITERIA REMAINS UNCHANGED BUT STILL
LINGERING ISSUES THAT NEED TO BE DEALT WITH PLANNERS
ARISING FROM ENHANCED ROLES & DELIVERABLES.
� OPPORTUNITIES FOR DEVELOPMENT OF NEW METHODS RISK
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� OPPORTUNITIES FOR DEVELOPMENT OF NEW METHODS RISK
ASSESSMENT AND OPTIMIZATION TOOLS FOLLOWING
IMPLEMENTATION OF INTEGTRATED UTILITY IT APPLICATIONS
( GIS-BASED NETWORK MGT SYSTEM, OMS, CBM, SCADA ETC)
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THANK YOU!
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THANK YOU!
LooCK