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

www.themegallery.com2ILSAS

� Design Principles/ Considerations/Criteria

� Issues & Challenges in Distribution Planning

� Evolution of Planning Methodologies

� Summary & Conclusions


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

www.themegallery.com4

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


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


• 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


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


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’)’)


Cover Page First PageILSAS

EXAMPLE OF RULES (‘EXAMPLE OF RULES (‘PERATURANPERATURAN’)’)

Contoh daripada


Contoh daripada Akta Bekalan Elektrik 1990

ILSAS

EXAMPLE OF INDUSTRY CODEEXAMPLE OF INDUSTRY CODE


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


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


� 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


� 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)


� 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)


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


Σ No of Customer Interrupted

∑

∑

=

==n

1i

i

n

1i

ii

C

dC

Where:


di = Restoration time of each interruption event (in min)


� 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


N

Cn

1i

i∑==Where:


N = No of customers served


SUBSTATION FIRM CAPACITY

� System must be operated below firm capacity

� Substation uses (PMU/PPU/SSU/PE)


� 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.


� 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)


� 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.


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


� 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)


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)

www.themegallery.com26MFuad

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

www.themegallery.com27MFuad

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:


� 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.


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


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)


� 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.


MV NETWORK

CONFIGURATION

32

TYPICAL DISTRIBUTION SYSTEM

12 kV 132kV

33kV

33kV11kV PPU

POWER

TRANSMISSION

LINE

U/G & O/H


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


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


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



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



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



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



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



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





n-1 bus-bar element Yes


n-1 transformer element Yes


SCADA, Sub-station

and feeder

automation

but from different secondary

buses ( see fig.)


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)








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


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


open points and fed by the

different PMU sources

OPERATIONAL

CONTROL

APPLICATION POLICY /

GUIDELINESNETWORK MODELS

APPLICATION GUIDE

~ SECURITY & CONTINGENCY CRITERIA (2/2)





n-1 feeder element No



No SCADA/DA


automation


automation

Level 4

n-1 feeder element No


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


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


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


• 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


√ L1 L2

X L2 L2

PMU PMUPPU PPU

PMU PMUPPU PPU

Level 1 & 2 attainable with SCADA


PARALLEL FEEDER SOURCE

√ N/A N/A

X L2 L2

X L2 L2


√ L1 L2

X L2 L2

PMU PMUPPU

PMU PMUPPUPPU



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


� 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


� 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


� 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)


� MV overhead bare line system (33kV in particular) should be

equipped with auto-recloser & sectionaliser

LooCK


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


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)


� 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


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).


� 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.


� 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


� 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


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%.


� 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


� Add new feeder

� Reduce feeder length

� Reduce volt-drop losses (long lines/feeder)

� Load balancing

WHY VAr MANAGEMENT

� Voltage regulation

� Optimize distribution capacity


� 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


� Other advantages of cap bank

� Points to note with cap bank

� operation

� safety

� maintenance

SYSTEM STUDIES & SYSTEM STUDIES &

TECHNICAL PROPOSALTECHNICAL PROPOSAL

www.themegallery.com62Rosemi

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


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

Rosemi

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


• 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

Rosemi

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


5MW to 25MW MV 33kV

> 25MW MV 132kV

Rosemi

STEP 3: CHOOSE DESIGN STEP 3: CHOOSE DESIGN

FORMAT FOR (nFORMAT FOR (n--1) SYSTEM1) SYSTEM

B

D E

CA


PlanSecurity Criteria

Loading CriteriaElement

A (n-1) <50%

B (n-1) <50%

C (n-1) <50%

D (n-2) <50%

E (n-2) <50%

Rosemi

%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


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

Rosemi

STEP 4: FIND SITE LOCATION STEP 4: FIND SITE LOCATION

& ELECTRICAL LOCATION& ELECTRICAL LOCATION


Site LocationSite Location

Electrical LocationElectrical Location

Rosemi

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


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

Rosemi

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


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

Rosemi

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


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

Rosemi

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


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

Rosemi

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%


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%

Rosemi

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%


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)


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

Rosemi

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


% 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













Contingency

B

Contingency

A

Rosemi


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


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


� DETERMINISTIC VS PROBABLISTIC CRITERIA.

� NETWORK STRUCTURE & CONFIGURATION

LooCK


� PROTECTION & AUTOMATION

� EQUIPMENT DESIGN, SELECTION & STANDARDIZATION

� ASSET REPLACEMENT DECISIONS & PLANS


� DG CONNECTIONS

� LOAD FORECASTING

LooCK


� SYSTEM STUDIES: METHODS, TOOLS & DATABASES

� INVESTMENT APPRAISAL METHODS

www.themegallery.com82LooCK


EVOLUTION IN

PLANNING

METHODOLOGIES

83

METHODOLOGIES

EVOLUTION IN PLANNING METHODOLOGY

RISK-BASED PLANNING

www.themegallery.com84LooCK

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


METHODOLOGIES THAT COULD EFFECTIVELY DEAL WITH

RELIABILITY AND RISK ASSESSMENT, LIFE CYCLE COSTING FOR

ASSET DEVELOPMENT AND REPLACEMENT DECISIONS.

LooCK

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


� 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)

LooCK

THANK YOU!


THANK YOU!

LooCK

uniten arsepe 08 l2

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