HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation...

HJ International Latin America, Inc.

Installed capacity of Installed capacity of Distribution Distribution Transformers. Transformers.

The situation and a The situation and a proposal of solution.proposal of solution.


Presentation of the Presentation of the situationsituation

There is an excess of installed capacity of distribution transformers


An interesting ratioAn interesting ratio

• Invoiced energy, Gwh per yearInvoiced energy, Gwh per year

Fi = -----------------------------------------------------Fi = -----------------------------------------------------

CITD * fp * 24 * 360CITD * fp * 24 * 360

CITD: Installed capacity in Distribution Transformers, CITD: Installed capacity in Distribution Transformers, GVAGVA

fp: Global system power factorfp: Global system power factor


Determining the Determining the magnitude of the Over-magnitude of the Over-

CapacityCapacity• One indicator of the One indicator of the

over-capacity is the over-capacity is the ratio between the ratio between the installed capacity of installed capacity of Power Transformers Power Transformers in the Substations in the Substations at the end of the at the end of the transmission lines transmission lines and …..and …..



CapacityCapacity

• ……. the total installed . the total installed

capacity of distribution capacity of distribution

transformers reducing transformers reducing

medium voltage to low medium voltage to low

voltage levels.voltage levels.



CapacityCapacity• In most cases, the ratio R : In most cases, the ratio R :

• Installed Capacity of Distribution TransformersInstalled Capacity of Distribution Transformers

R = -------------------------------------------------------------R = -------------------------------------------------------------

Installed Capacity of Power TransformersInstalled Capacity of Power Transformers

• > 2.0 > 2.0


Something to think Something to think about….about….

• Since the flow of energy in the system Since the flow of energy in the system is the same for Power and Distribution is the same for Power and Distribution Transformers…..Transformers…..

• AVERAGE LOADAVERAGE LOAD AVERAGE LOAD AVERAGE LOAD DISTRIBUTIONDISTRIBUTION POWER POWER TRANSFORMERSTRANSFORMERS TRANSFORMERSTRANSFORMERS

• = = ----------------------------------------

• RR


Now, transformer size can Now, transformer size can be selected based on be selected based on

maximum load (Utilization maximum load (Utilization Factor, Fu)...Factor, Fu)...

0

0.2

0.4

0.6

0.8

1

1.2

1.4Loadp.u.

rmsequiv

Trafosizep.u.

• Max Load

Fu = ----------------

Transf. Size


……or based on the rms or based on the rms equivalent load... equivalent load...

TRANSFORMER TRANSFORMER AVERAGE LOAD : AVERAGE LOAD :

rms equiv. loadrms equiv. load

La = --------------------La = --------------------

Transf. sizeTransf. size0

0.2

0.4

0.6

0.8

1

1.2

1.4

1 5 9

13

17

21

Load p.u.

rms equiv

Trafo sizebased onrms load

Trafo sizebased onpeak load

TRANSFORMER OVERSIZE


Then we realize that...Then we realize that...

• If transformers are selected just If transformers are selected just thinking of maximum load…thinking of maximum load…

• ……this conduces to select capacities this conduces to select capacities much higher than the actually needed.much higher than the actually needed.

• Transformer sizes should be selected Transformer sizes should be selected as possible based on the average load as possible based on the average load taken from the actual load curve taken from the actual load curve (projected)…(projected)…• It is important to take advantage of the It is important to take advantage of the transformer transformer overload capacityoverload capacity..


Oversize magnitude comes Oversize magnitude comes from...from...

• Ratio R, commented before, andRatio R, commented before, and

• A ratio K depending on the load curve A ratio K depending on the load curve and defined as...and defined as...

• K = Fu / La = Maximum load / Average K = Fu / La = Maximum load / Average loadload• Maximum oversize magnitude comes Maximum oversize magnitude comes from the product given by…….from the product given by…….

• OSmax = R * KOSmax = R * K


Something more to think Something more to think about….about….

• Since the flow of energy in the system Since the flow of energy in the system is the same for Power and Distribution is the same for Power and Distribution Transformers…..Transformers…..

• AVERAGE LOADAVERAGE LOAD Fu OF THE Fu OF THE DISTRIBUTIONDISTRIBUTION POWER POWER TRANSFORMERSTRANSFORMERS TRANSFORMERSTRANSFORMERS

• = = ----------------------------------------

• R * KR * K


A typical value for K is 1.6. A typical value for K is 1.6. This makes OSmax = 4.8 This makes OSmax = 4.8

Thus, the average load of distribution Thus, the average load of distribution transformers in the system can be so transformers in the system can be so

low as….low as….

UTILIZATION FACTOR POWER TRANSFORMER

AVERAGE LOAD DISTRIBUTION TRANSF.

90 % 18.8 %

70 % 14.6 %

50 % 10.4 %

30 % 6.30 %


Immediate goal is...Immediate goal is...

• To increase the average load of To increase the average load of Distribution Transformers in the Distribution Transformers in the System.System.

TIP Importance of the load losses

in this process


Average Load of Distribution Average Load of Distribution Transformers in the system Transformers in the system

(Instance)(Instance)

0-10%>22%10-22%

• Average transformer ratings may be reduced in the system by factors from 2 up to 5 !!


There are 2 aspects to be There are 2 aspects to be taken into account as taken into account as

increasing average load of increasing average load of distribution transformersdistribution transformers

•TRANSFORMER LOSSESTRANSFORMER LOSSES

•TRANSFORMER FAILURESTRANSFORMER FAILURES

However….However….


Increasing or reducingIncreasing or reducingthrough higher La in the system??through higher La in the system??

LOSSES COST...

0

20,000

40,000

60,000

80,000

100,000

120,000

15% 25% 60% 80% 110%

La

USD

TotalCost

EnergyCost

AssetsCost


WHERE WE ARE TODAY WHERE WE ARE TODAY INDICATES OUR COMPROMISEINDICATES OUR COMPROMISE

CURRENT CURRENT SITUATIONSITUATION

20 %20 %WHERE WE SHOULD BE WHERE WE SHOULD BE

60 A 75 60 A 75 %%


It is experienced an increment of It is experienced an increment of overload failures along with a overload failures along with a

higher “La” in the systemhigher “La” in the system

0102030405060708090

25% 80% 110%

La

OverloadsShortcircuitsLightingOthers

UNLESS THE TRANSFORMER BE UNLESS THE TRANSFORMER BE ADEQUATELY PROTECTED AGAINST ADEQUATELY PROTECTED AGAINST

OVERLOADS !!OVERLOADS !!

TRANSFORMER FAILURESTRANSFORMER FAILURES


Our proposal of solution Our proposal of solution is...is...

THE SELF PROTECTED THE SELF PROTECTED TRANSFORMERTRANSFORMER• To increase the Average Load “La” without To increase the Average Load “La” without increasing overload failuresincreasing overload failures

• To allow the reduction of the Over-Capacity To allow the reduction of the Over-Capacity factor “R” along with the losses in the system factor “R” along with the losses in the system without increasing other related costswithout increasing other related costs

• To reduce installation costsTo reduce installation costs• To get a significant reduction of the overall To get a significant reduction of the overall transformers failure rate in the distribution transformers failure rate in the distribution systemsystem


• P – A – U – S - EP – A – U – S - E


SUMMARY OF THE SUMMARY OF THE SELF - PROTECTION SELF - PROTECTION

PRINCIPLESPRINCIPLES

A GUIDE THAT SHOWS THE MAIN A GUIDE THAT SHOWS THE MAIN CONCEPTS TO SUCCESSFULLY CONCEPTS TO SUCCESSFULLY

INTRODUCE THE SELF - PROTECTION INTRODUCE THE SELF - PROTECTION PHILOSOPHYPHILOSOPHY


THE SELF - PROTECTION THE SELF - PROTECTION PHILOSOPHYPHILOSOPHY

PRINCIPLE PRINCIPLE

# 1# 1IMPORTANT NOTE

APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY


Using Self Protected Transformers is Using Self Protected Transformers is not only to add some components to not only to add some components to

the transformer…!!the transformer…!!

ARRESTERBREAKER

FUSES

SIGNALLIGHT

OPERATING HANDLE & EMERGENCY OVERLOAD


……it is to use a COMPLETE it is to use a COMPLETE philosophy to protect and handle philosophy to protect and handle

with...with...

THE TRANSFORMERS...THE TRANSFORMERS...


……it is to use a COMPLETE it is to use a COMPLETE philosophy to protect and handle philosophy to protect and handle

with...with...

...THE DISTRIBUTION ...THE DISTRIBUTION SYSTEM... SYSTEM...


……it is to use a complete it is to use a complete philosophy to protect and handle philosophy to protect and handle

with...with...

...AND THE CUSTOMERS ...AND THE CUSTOMERS !!



PRINCIPLE PRINCIPLE




Main transformer protecting tasks, Main transformer protecting tasks, including selection and including selection and

coordination…coordination… ARE TRANSFORMER MANUFACTURER ISSUES !!ARE TRANSFORMER MANUFACTURER ISSUES !!

CONVENTIONALCONVENTIONAL SELF - PROTECTEDSELF - PROTECTED

BLACK BOX


This causes...This causes...

• Simplification of the transformers installationSimplification of the transformers installation

• Less warranty discussions between Utility and Less warranty discussions between Utility and transformer manufacturertransformer manufacturer

• Longer warranty termsLonger warranty terms



PRINCIPLE PRINCIPLE




HV Fuse should be HV Fuse should be internally connectedinternally connected

• THIS TO AVOID:THIS TO AVOID:

• Fuse rating changedFuse rating changed

• Dangerous operation Dangerous operation of damaged unitsof damaged units

• Miss-coordination of Miss-coordination of the transformer the transformer protecting devicesprotecting devices


This arises a question...This arises a question...

IS IT NEEDED TO IS IT NEEDED TO INSTALL THE INSTALL THE FUSED CUT-OUT FUSED CUT-OUT

WITH EVERY WITH EVERY TRANSFORMERTRANSFORMER

??


Some responses from self-Some responses from self-protecting principles to this protecting principles to this

question are:question are:The load-break operation is made in LV side by operating The load-break operation is made in LV side by operating the breaker operating handle (this is a safer operation)the breaker operating handle (this is a safer operation)

Fuse has one main and one secondary function: Fuse has one main and one secondary function: • MAIN FUNCTION of the fuse is to act like an over-MAIN FUNCTION of the fuse is to act like an over-current protection by isolating a failed transformer current protection by isolating a failed transformer from the system.from the system.• SECONDARY FUNCTION is to act like a back-up SECONDARY FUNCTION is to act like a back-up protectionprotectionTo eliminate the use of fused Cut-out with every To eliminate the use of fused Cut-out with every

transformer it is important to have well trained people to transformer it is important to have well trained people to handle with energized lineshandle with energized linesIt is strongly recommended to use Wildlife Guards in those It is strongly recommended to use Wildlife Guards in those case fused Cut-out is not usedcase fused Cut-out is not used


Cut-outs continue to be an Cut-outs continue to be an essential part of the distribution essential part of the distribution circuits for circuit maintenance circuits for circuit maintenance

proposals...proposals...

SPECIALLY AT THE SPECIALLY AT THE BEGINNING OF THE BEGINNING OF THE CIRCUIT BRANCHESCIRCUIT BRANCHES



PRINCIPLE PRINCIPLE




Signal Light is an essential Signal Light is an essential part of one integral self-part of one integral self-

protecting policy to get an protecting policy to get an effective load managementeffective load management

• OFFOFF

• SHOWS A NORMAL LOAD SHOWS A NORMAL LOAD OR CIRCUIT SITUATIONOR CIRCUIT SITUATION

• ONON

• SHOWS AN ABNORMAL SHOWS AN ABNORMAL LOAD OR CIRCUIT LOAD OR CIRCUIT

SITUATIONSITUATION


The signal light is an essential The signal light is an essential part of an integral self-part of an integral self-

protection policyprotection policyIt’s an easy and economical way to detect any thermal abnormal operating condition without the need of costly measuring and monitoring methods

It operates like a PREVENTIVE ALARM without customer disconnection

It can be factory calibrated to meet the actual load curve requirements and the desired trip conditions

It’s a very effective way to detect energy robbery

If attended, it’s a very effective way to reduce non-planned loadbreaks



PRINCIPLE PRINCIPLE




Arresters are to be Arresters are to be installed at the installed at the

transformer’s tank transformer’s tank

IN CONVENTIONAL IN CONVENTIONAL TRANSFORMERS TRANSFORMERS CUT-OUT FUSES CUT-OUT FUSES

WOULD BE WOULD BE INSTALLED UP-INSTALLED UP-

STREAMSTREAM


Arresters arranged far from transformer Arresters arranged far from transformer tank makes the transformer not right tank makes the transformer not right

protectedprotected



PRINCIPLE PRINCIPLE




Transformer Load Management Transformer Load Management (TLM)(TLM)

in servicein service is to be made is to be madeAny overload, at peak hours, above the maximum allowed is to be detected and alarm is to be given

by the transformer itself

Any transformer giving reiterative alarm information is to be changed for a larger

capacity unit. Before that, a load analysis is to be made

According to above change policy a SELECTIVE transformers load analysis in the system is made.

Signal light acts like a sample selector.

Overload capacity of the transformers is to be actually used



PRINCIPLE PRINCIPLE




Assets Management of the Assets Management of the transformerstransformers

in servicein service is to be made is to be madeLIKE ANY OTHER ASSET, LIKE ANY OTHER ASSET,

TRANSFORMER’S LIFE AT THE TRANSFORMER’S LIFE AT THE INSTALLATION PLACE IS TO BE INSTALLATION PLACE IS TO BE PLANNED ACCORDING TO THE PLANNED ACCORDING TO THE LOAD AND TO A REPLACEMENT LOAD AND TO A REPLACEMENT

POLICYPOLICY

AN AN INVENTORY INVENTORY ROTATION ROTATION

POLICY POLICY SHOULD BE SHOULD BE DEFINED !DEFINED !



OTHER OTHER PRINCIPLES & PRINCIPLES & FINAL ISSUESFINAL ISSUES

IMPORTANT NOTE



UNBALANCED LOADSUNBALANCED LOADS

UNBALANCED LOADS IN 3F BREAKERS CAN UNBALANCED LOADS IN 3F BREAKERS CAN CAUSE PREMATURE SIGNAL LIGHT OR BREAKER CAUSE PREMATURE SIGNAL LIGHT OR BREAKER

TRIP.TRIP.FOR THIS REASON OUR PRINCIPLE # 6 CALLS TO FOR THIS REASON OUR PRINCIPLE # 6 CALLS TO

MAKE A LOAD ANALYSIS IN EACH CIRCUIT MAKE A LOAD ANALYSIS IN EACH CIRCUIT CAUSING SIGNAL LIGHT OR BREAKER TRIP.CAUSING SIGNAL LIGHT OR BREAKER TRIP.

AGAIN SELF PROTECTION PHILOSOPHY AGAIN SELF PROTECTION PHILOSOPHY APPLICATION ACTS LIKE PREVENTIVE WAY TO APPLICATION ACTS LIKE PREVENTIVE WAY TO DETECT SYSTEM PROBLEMS WITHOUT HIGH DETECT SYSTEM PROBLEMS WITHOUT HIGH

COSTS INTERRUPTIONS.COSTS INTERRUPTIONS.

UNBALANCED LOADS ARE EASILY DETECTED IN A UNBALANCED LOADS ARE EASILY DETECTED IN A 3F BANK OF 1F SELF PROTECTED UNITS.3F BANK OF 1F SELF PROTECTED UNITS.


Making an economical evaluation Making an economical evaluation of a conventional transformers of a conventional transformers

project vs. self-protected project project vs. self-protected project TRANSFORMER SIZES COMPARED ARE TRANSFORMER SIZES COMPARED ARE

DIFFERENT !!DIFFERENT !!

SELF - PROTECTEDSELF - PROTECTEDCONVENTIONALCONVENTIONALkVA RATING = X kVA RATING = X/2kVA RATING = X/2


Introducing Self Protecting Introducing Self Protecting Philosophy can help to simplify Philosophy can help to simplify

and to reduce costs of Distribution and to reduce costs of Distribution CircuitsCircuits

• No use of cross No use of cross arms for arrestersarms for arresters

• No use of cross No use of cross arms for Cut-outsarms for Cut-outs

• Use of line spacers Use of line spacers & wildlife guards& wildlife guards

• No LV fuse holdersNo LV fuse holders


LOAD HARMONICSLOAD HARMONICS

-1.5

-1

-0.5

0

0.5

1

1.5

LOAD HARMONICS CAUSING OVER HEATING INSIDE THE LOAD HARMONICS CAUSING OVER HEATING INSIDE THE TRANSFORMERS WILL ALSO CAUSE OVER HEATING OF TRANSFORMERS WILL ALSO CAUSE OVER HEATING OF

THE BREAKER’S BIMETALIC, TRIPPING IT.THE BREAKER’S BIMETALIC, TRIPPING IT.


Breaker LossesBreaker Losses

72.7%

24.9%

2.4%

LOAD LOSSESNO LOAD LOSSESBREAKER LOSSES

ANY COST ANALYSIS OF THE BREAKER LOSSES BASED ANY COST ANALYSIS OF THE BREAKER LOSSES BASED ON THE ACTUAL LOAD CURVE WILL SHOW THAT IT IS ON THE ACTUAL LOAD CURVE WILL SHOW THAT IT IS

TOO LOW PER YEAR MAKING THE LOW VOLTAGE TOO LOW PER YEAR MAKING THE LOW VOLTAGE BREAKER THE MOST ECONOMICAL AND FLEXIBLE BREAKER THE MOST ECONOMICAL AND FLEXIBLE

ALTERNATIVE TO PROTECT THE TRANSFORMERALTERNATIVE TO PROTECT THE TRANSFORMER


Light & Breaker trip Light & Breaker trip temperatures can be selected temperatures can be selected

based on the kWh demand based on the kWh demand curvecurve

0

0.2

0.4

0.6

0.8

1

1.2

kWhDEMANDLIGHTTRIPBREAKERTRIP

LOAD CURVELOAD CURVE

kWh DEMAND CURVEkWh DEMAND CURVE

TEMPERATURE PROFILTEMPERATURE PROFIL

TRIP TEMPERATURES TRIP TEMPERATURES DETERMINATIONDETERMINATION


SELF PROTECTION APPLICATION COVERS SELF PROTECTION APPLICATION COVERS SMALL DISTRIBUTION TRANSFORMERS (UP TO SMALL DISTRIBUTION TRANSFORMERS (UP TO

500kVA) THAT NORMALLY DON’T USE 500kVA) THAT NORMALLY DON’T USE THERMOMETERS OR LIQUID LEVEL GAUGESTHERMOMETERS OR LIQUID LEVEL GAUGES

BREAKER’S BIMETALIC ACTS LIKE A TEMPERATURE BREAKER’S BIMETALIC ACTS LIKE A TEMPERATURE DETECTOR WITH ALARM & TRIP FEATURES WHEN DETECTOR WITH ALARM & TRIP FEATURES WHEN

INTERNAL TRANSFORMER’S TEMPERATURES REACH INTERNAL TRANSFORMER’S TEMPERATURES REACH DANGEROUS PREDETERMINED LEVELSDANGEROUS PREDETERMINED LEVELS

BREAKER’S BIMETALIC ACTS ALSO LIKE A LOW OIL BREAKER’S BIMETALIC ACTS ALSO LIKE A LOW OIL LEVEL DETECTOR WITH ALARM & TRIP FEATURES WHEN LEVEL DETECTOR WITH ALARM & TRIP FEATURES WHEN INTERNAL OIL REACHES LEVELS WHERE THE BIMETAL INTERNAL OIL REACHES LEVELS WHERE THE BIMETAL

GET NOT OIL IMMERSEDGET NOT OIL IMMERSED


Expected life of the Expected life of the transformer oiltransformer oil

DUE TO THE OPERATING TEMPERATURE DUE TO THE OPERATING TEMPERATURE CONTROL, SELF-PROTECTED TRANSFORMERS CONTROL, SELF-PROTECTED TRANSFORMERS MAKE OIL LIFE LONGER THAN CONVENTIONALMAKE OIL LIFE LONGER THAN CONVENTIONAL

POSSIBLE OIL DETERIORATION CAUSED BY POSSIBLE OIL DETERIORATION CAUSED BY UNDER-OIL ARCING IS FAR COMPENSATED BY THE UNDER-OIL ARCING IS FAR COMPENSATED BY THE LOW OIL OPERATING TEMPERATURE DURING THE LOW OIL OPERATING TEMPERATURE DURING THE

LIFE OF SELF-PROTECTED TRANSFORMERSLIFE OF SELF-PROTECTED TRANSFORMERS

NUMBER OF BREAKER OPERATIONS DURING NUMBER OF BREAKER OPERATIONS DURING TRANSFORMER’S LIFE IS MINIMIZED BY MAKING TRANSFORMER’S LIFE IS MINIMIZED BY MAKING

A RIGHT USE OF THE SIGNAL LIGHTA RIGHT USE OF THE SIGNAL LIGHT


Customized thermal Customized thermal protection based on heat protection based on heat

run testrun test

0

20

40

60

80

100

120

140

1601 6 11

16

21

HSTEMPERATLIGHTTRIPBREAKERTRIP

TEMPERATURE RANGE TEMPERATURE RANGE FOR TRIP CALIBRATION FOR TRIP CALIBRATION

SIGNAL LIGHT SIGNAL LIGHT BREAKER BREAKER

OTHER PROTECTING OTHER PROTECTING DEVICES LIKE FUSES OR DEVICES LIKE FUSES OR COOPER MAGNEX ARE COOPER MAGNEX ARE

NOT SO FLEXIBLENOT SO FLEXIBLE

THERE IS A THERE IS A DIFFERENT DIFFERENT

CALIBRATION CALIBRATION AVAILABLE EVEN AVAILABLE EVEN

FOR THE SAME kVA FOR THE SAME kVA RATINGRATING


COMPARISON BETWEEN SECONDARY COMPARISON BETWEEN SECONDARY BREAKERBREAKER

VSVSPRIMARY MAGNEX INTERRUPTERPRIMARY MAGNEX INTERRUPTER

SPECIFICATION SECONDARY BREAKER

PRIMARY MAGNEX INTERRUPTER

PRICE X 2*X

SIGNAL LIGHT AVAILABLE NOT AVAILABLE

PROTECTION SELECTIVITY

CLEARLY DEFINED BETWEEN HV FUSE (TRAFO FAILURE) &

LV BREAKER

BOTH PROTECTING DEVICES MIGHT ACT BY A TRAFO

FAILURE PROTECTION CHARACTERISTICS

FLEXIBLE ACCORDING TO HEAT RUN TEST

ONLY ONE SETTING PER kVA




…CONTINUED...…CONTINUED...



PRODUCT COVERAGE

SINGLE AND THREE PHASE

TRANSFORMERS

SINGLE PHASE TRANSFORMERS

CUT OUT

CAN BE

ELIMINATED

CAN’T BE ELIMINATED DUE

TO LOW INTERRUPTING

RATING LOSSES HIGHER BUT

MINIMUM LOWER




…CONTINUED…CONTINUED



EVENTUAL OPERATION IN 3F SYSTEMS

3 POLES OPERATION (NO 1

OR 2 PHASES OPERATION)

1 POLE OPERATION (ALLOWS 1 OR 2

PHASES OPERATION)

EVENTUAL OPERATION IN 3F SYSTEMS

ONE SINGLE PIECE

THREE UNITS &

THREE HANDLES OPERATION IN 1F SYSTEMS PHASE TO PHASE

ONE SINGLE PIECE

2 BIMETALS

2 PIECES ARE

NEEDED


SUMMARYSUMMARY

• We have seen during this presentation:We have seen during this presentation:

• Over capacity problem of the Distribution Systems & causesOver capacity problem of the Distribution Systems & causes

• Our proposal of solution Our proposal of solution

• Effect of the over capacity & its solution on losses and failuresEffect of the over capacity & its solution on losses and failures

• What is and how works the self protected transformers What is and how works the self protected transformers conceptconcept

• Principles of Self Protection philosophy & performance of a Principles of Self Protection philosophy & performance of a self protected unit in the distribution circuitsself protected unit in the distribution circuits

• How to begin a change process to successfully introduce the How to begin a change process to successfully introduce the Self Protection philosophy without mistakesSelf Protection philosophy without mistakes


E N DE N D

HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation...

Documents

Transcript of HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation...