Transcript
Page 1: Presentation on All Products With Detailed CCV and CT
Page 2: Presentation on All Products With Detailed CCV and CT

Instrument TransformersBangalore Site

January 2006

Deepak.VProducts Profile and Details

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> Instrument Transformers - (ITR)- RMK Site - December 20053 3

A Competitive Site in an International Group

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> Instrument Transformers - (ITR)- RMK Site - December 20054 4

4 Units, 874 Employees *

AREVA T&D Instrument Transformers Manufacturing Unit

Brazil

Mexico

France

India

* 2005 figures

A Competitive Site in an International Group

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> Instrument Transformers - (ITR)- RMK Site - December 20055 5

CODENSACOLOMBIA

245 KV

EDELCAVENEZUELA

800 KV

SEGBAARGENTINA

525 KV

UTEURUGUAY

525 KV

FURNASBRAZIL800 KV

TRANSELEC CHILE 525 KV

AREVA T&D Instrument Transformers Empower Satisfied Partners Worldwide

BPAUSA

525 KV

HYDRO QUEBECCANADA

800 kV

AEPUSA

800 kV

BC HYDROCANADA525 KV

APSUSA

525 KV

CFEMEXICO420 kV

GUIZHOU E.P.C.CHINA525 kV

PLNINDONESIA525 kV

TNBMALAYSIA275 KV

PGCIL/NTPC/SEB INDIA420 kV

EVNVIETNAM550kV

KEGOCKAZAKHSTAN500 kV

POWERNETAUSTRALIA550 KV

RAO EESRUSSIA800 kV

ZHEJIANGCHINA525 kV

ONEMOROCCO

245 KV

SONELGAZALGERIA

245 KV

CIEIVORY COAST

245 KV

ESKOMS. AFRICA

420 KV

STEGTUNISIA245 KV

EEAEGYPT245 KV

REESPAIN420 KV

EDFFRANCE420 KV

NGTUK

420 KV

ELIABELGIUM

420 KV

E -ONGERMANY

420 KV

ENELITALY420 KV

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> Instrument Transformers - (ITR)- RMK Site - December 20056 6

AREVA T&D Instrument Transformers are installed in the four corners of the world :

AREVA T&D Instrument Transformers

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> Instrument Transformers - (ITR)- RMK Site - December 20057 7

Bangalore Site

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> Instrument Transformers - (ITR)- RMK Site - December 20058 8

AREVA T&DInstrument Transformers India Private Limited

Built area : 16,350 sq.m

People : 250

Workers : 173

Engineers & Employees : 77

Activities

HV Instrument Transformers

Line Traps

Condenser Bushings

Bangalore

India - Bangalore Site

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> Instrument Transformers - (ITR)- RMK Site - December 20059 9

AREVA T&DInstrument Transformers India Private Limited

India - Bangalore Site

HV Instrument Transformers

Current Transformers (Paper-oil) up to 765 kV

Capacitor Voltage Transformers (Paper/Film/Oil) up to 765 kV

Line Traps up to 1mh / 3150A & 800kV

Condenser Bushings up to 420 kV

Page 10: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200510 10

An History of Innovative Excellence

1976 - WSI is created (Line Traps and Capacitor Voltage Transformers)

1977 - Started Bushings manufacture

1983 - WSI started Current Transformers production (420 kV)

1991 - ISO-9001 Certification

2000 - WSI Bangalore unit sold to ALSTOM group

2002 - Commercialization of mixed dielectric technology (CCV) for Capacitor Voltage Transformers as per AREVA T&D design

2005 - IS0-14001:2004 certification for environmental system

2005 - Plant becomes part of AREVA T&D

2005 - Top core Current Transformers (CTH) transferred from AREVA T&D

Bangalore Site at a Glance

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> Instrument Transformers - (ITR)- RMK Site - December 200511 11

A leader and a Pioneer

30 years of operating experience in India

First manufacturer in India for 3600 Amps Current Transformers

Only manufacturer of Wall-to Wall and Oil-Oil bushings in India

First manufacturer of 400 kV (8800pF) Capacitor Voltage Transformers in India

First manufacturer of 1mH / 3150 Amps Line Traps in India

Over 25,000 Current Transformers and Capacitor Voltage Transformers in operation

Over 40,000 Line Traps on site

Bangalore Site at a Glance

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> Instrument Transformers - (ITR)- RMK Site - December 200512 12

We are un-compromising about our quality production process techniques, safety and efficiency

State-of-the-art facility for oil treatment and impregnation

Optimized flow of materials and components

“Dust-free” room for Capacitor Voltage Transformers winding

Current Transformers taping carried out in high pressure room

In-house testing capability

World-class Manufacturing

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> Instrument Transformers - (ITR)- RMK Site - December 200513 13

We are un-compromising about our quality production process techniques, safety and efficiency

Only qualified, skilled/trained and experienced personnel

Training programs to maintain high performances

Safe & pleasant work environment to encourage efficient, quality work

Technical & commercial interactions between Bangalore and other global AREVA T&D Units

Our experts regularly participate in technical conferences

People Power

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> Instrument Transformers - (ITR)- RMK Site - December 200514 14

We have embarked on a total quality process

Reliable quality management system

Continuous improvement through effective communication

Innovation & investment in the products, processes, services, environment and human resources

ISO-9001:2000 certification

ISO-14001:2004 certification

Quality First

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> Instrument Transformers - (ITR)- RMK Site - December 200515 15

Bangalore Site - Product LinesOverview

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> Instrument Transformers - (ITR)- RMK Site - December 200516 16

Instrument Transformers in IndiaProduct Lines

Hair pin / eye bolt design current transformers

ITT and IT type

Designed according to our Indian customers’ most exacting requirements

Extensive field experience

Low maintenance

Designed to withstand 600 multiple chopped impulse

Flexible design

These CTs are installed throughout India and are highly respected by network managers and substation personnel alike

HV Instrument Transformers

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> Instrument Transformers - (ITR)- RMK Site - December 200517 17

Instrument Transformers in IndiaProduct Lines

Top Core design current transformers

CTH type up to 765 kV

Reinforced security design

Top core design with metal head

High quality paper-oil insulation. Oil expansion by stainless steel bellows

Stable accuracy over a long period of time

Extensive experience in highly active seismic regions

Compact construction

Single, double or triple ratio at the primary side

Top-of-the-range Current Transformers (CTH type) : the next wave of Bangalore production

HV Instrument Transformers

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> Instrument Transformers - (ITR)- RMK Site - December 200518 18

Instrument Transformers in IndiaProduct Lines

Capacitor Voltage Transformers (Paper/Film/Oil)

CCV type up to 765 kV

Optimized design for high reliability and longevity; maintenance free

Superior transient response

Optimized insulation technology (mixed PPR / Paper), high grade synthetic oil

Effective protection against ferroresonance

Operations as coupling capacitor for power line carrier transmission

Stability of capacitance and accuracy over many yearsThis range is manufacturing in India using the most

modern insulation impregnation technology and equipment

HV Instrument Transformers

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> Instrument Transformers - (ITR)- RMK Site - December 200519 19

Instrument Transformers in IndiaProduct Lines

up to 800 kV

can operate within the 30 kHz to 500 kHz frequency range

Flexible mounting options

High short-circuit withstand capability

Light weight

Reliable open-style design (OSD)

Excellent cooling capabilities

Extremely reliable tuning devices

Maintenance free

Over 40,000 Line Traps on site

Line Traps

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> Instrument Transformers - (ITR)- RMK Site - December 200520 20

Instrument Transformers in IndiaProduct Lines

Oil-to-air

Oil-impregnated paper (OIP)

External shell : porcelain envelope

Partial discharges < 5pC at 1.5 Un / 3

Specially treated mineral oil

Power factor tap, air draining plug & oil side shield provided

Prismatic oil sight glass with option of MOLG above 145 kVFlange of aluminum alloy casting

High creepage bushings on requestSuitable for connecting outdoor equipment to high voltage

transformers

High voltage Condenser Bushings up to 420 kV

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> Instrument Transformers - (ITR)- RMK Site - December 200521 21

Basics of Instrument Transformer

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> Instrument Transformers - (ITR)- RMK Site - December 200522 22

Magnetic circuit (core)

Instrument TransformerSensing function

U1 U2

Voltage sensor

Secondary Windings

Primary Windings

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> Instrument Transformers - (ITR)- RMK Site - December 200523 23

Instrument TransformerSensing function

I2

I1

Current sensor

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> Instrument Transformers - (ITR)- RMK Site - December 200524 24

I2

Instrument TransformerSensing function

I2

Current sensorMultiple secondary

I1

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> Instrument Transformers - (ITR)- RMK Site - December 200525 25

K : Transformation

ratio

PrimaryU1

Secondary

U2

Voltage Transformer :

Kn

n

U

U

2

1

2

1 1n

2n

Definition of an Instrument Transformer

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> Instrument Transformers - (ITR)- RMK Site - December 200526 26

PrimaryI1

Secondary I2

Current Transformer :

Kn

n

I

I

I.nI.n

1

2

2

1

2211

Ampere-TurnsConservation

Law

1n

2n

Definition of an Instrument Transformer

K : Transformation

ratio

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> Instrument Transformers - (ITR)- RMK Site - December 200527 27

K.Us

Instrument Transformer Error

Secondary

Primary

Up

Us

K

:Ratio error

Up (theoretically = k.US)

: Phase error

Voltage Transformer :Voltage Transformer :

s

p

U

Uk

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> Instrument Transformers - (ITR)- RMK Site - December 200528 28

Secondary

PrimaryIp

Is

K

TC : K=Ip

Is

K.Is :Ratio error

Ip

: Phase error

Current transformer :Current transformer :

Instrument Transformer Error

Page 29: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200529 29

Reminder

6eff

eff

10SBn2E

SBfn444E

....

...., Volts,W/m²,m²

at 50 Hz,Gauss, cm²

EMF Equation

Electrodynamical Forces

L

D

I1

F FI2

A]m,[N, 10.D

L.I.I.2F 721

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> Instrument Transformers - (ITR)- RMK Site - December 200530 30

Magnetization curve

Double logarithmic graph

Indu

ctio

n [G

auss

]

102

103

105

104

18.000 Gauss

Magnetic field [AT/cm]10-3 10-2 10-1 1

Compared to reference curves

1 Tesla = 104 Gauss

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> Instrument Transformers - (ITR)- RMK Site - December 200531 31

Induction [B]

Magnetic field [H]

Hc

Br

Br : Remanent InductionHc : Coercive field

Reminder

Hysteresis cycle

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> Instrument Transformers - (ITR)- RMK Site - December 200532 32

Reminder

R cuivre

I0

L0

RCF

Iw

Equivalent scheme of a coil with sinusoidal current

U

IwRH

I

U

I

I0

wiii0

A

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> Instrument Transformers - (ITR)- RMK Site - December 200533 33

Current TransformersTop Core Design - CTH range

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> Instrument Transformers - (ITR)- RMK Site - December 200534 34

1. Top cover

2. Oil level indicator

3. Oil expansion device

4. Metal box LV screen and cores

5. Bar-type or wound type primary

6. Paper-oil insulation

7. Porcelain insulator

8. LV screens

9. Secondary terminal box

10. Base

Full Range of HV Technologies

Current Transformers (Paper/Oil) up to 765 kV - CTH range

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> Instrument Transformers - (ITR)- RMK Site - December 200535 35

Current Transformers -- CTH 72.5 to 765 kV

Performance:

Un: 72.5 kV to 765 kV

In: up to 4800 A

In short circuit: up to 80 kA1” [Isc dyn : 200 kA peak]

Secondary cores : up to 8

Characteristics:

High quality paper-oil insulation

Top core design with metal head

Oil expansion by stainless steel bellows

Secondary cores : in aluminium box

Single, double or triple ratio at the primary side

Low maintenance

Linking the Power Chain

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> Instrument Transformers - (ITR)- RMK Site - December 200536 36

Linking the Power Chain

Current Transformers -- CTH 72.5 to 765 kV

Special accuracy classes: TPS, TPX, TPY, TPZ, PR

Explosion-proof design

Extensive experience in highly active seismic regions

Compact construction

Built for long life

Compliance with IEC, ANSI / IEEE or equivalent standards

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> Instrument Transformers - (ITR)- RMK Site - December 200537 37

Reinforced Security Design:

Limit the consequences of an internal failure by limiting the projections of parts, porcelain, and insulating oil.

CT Specific Design:

Reduced oil volume

Internal ground conductors with sufficient cross section for handling the fault current

Tank head designed to prevent the transmission, inside the porcelain insulator, of the over-pressure wave that originates in the head at the time of the fault

Reinforced Security Design

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> Instrument Transformers - (ITR)- RMK Site - December 200538 38

Failure Test at KEMA Laboratory

Characteristics of the test:

No load voltage: 10 kV RMS

Fault current: 40 kA RMS -- Fault duration: 200 ms

Time to fire the head: 9 ms

Fault energy: 8.9 MJ

Test results:

The CT is still at original position.

Limited oil fire

Top cover is perforated (500 mm dia).

Porcelain insulator intact

CT internal examination shows no arc inside the bushing. Grounding and secondary wiring are not affected.

Before the fault Just after the fault

CTH 525

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> Instrument Transformers - (ITR)- RMK Site - December 200539 39

Current Transformers - CTH

For years, tens of thousands of CTH have been installed all over the world

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> Instrument Transformers - (ITR)- RMK Site - December 200540 40

Current TransformersEye Bolt Design - IT range

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> Instrument Transformers - (ITR)- RMK Site - December 200541 41

1. Oil filling plug

2. Dome

3. Nitrogen filling valve

4. Collar

5. Primary terminal

6. Porcelain insulator

7. Insulated primary

8. Cover plate for tank

9. Tank

10. Secondary cores

Full Range of HV Technologies

Current Transformers (Paper/Oil) up to 245 kV - IT range

Eye bolt design

IT 245 Cross section

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> Instrument Transformers - (ITR)- RMK Site - December 200542 42

Eye Bolt DesignTechnical data

Rated voltage : 123 to 245 kV

Technology : Eye-Bolt

Expansion device : Nitrogen

Primary reconnection : 1-2

Rated primary current : 1200 Amp (1440 max)

Short circuit current : 40 kA 1”

Total weight (kg)

kV 72.5 145 245

kg 700 750 1200

IT range

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> Instrument Transformers - (ITR)- RMK Site - December 200543 43

Eye Bolt DesignActive Part Manufacturing

IT range

Primary conductor (1,2 or 4 turns)

Primary steel pipe

Paper insulation

Seconday cores

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> Instrument Transformers - (ITR)- RMK Site - December 200544 44

Eye Bolt DesignActive Part Manufacturing

IT range

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> Instrument Transformers - (ITR)- RMK Site - December 200545 45

Eye Bolt DesignVacuum Treatment

IT range

Oven

Active part

Target :Remove all the water trapped in

the paper (and in other materials) during insulation

process

Duration :Up to 3 weeks

Page 46: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200546 46

Current TransformersHair-Pin Design - ITT / IT range

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> Instrument Transformers - (ITR)- RMK Site - December 200547 47

1. Dome

2. Nitrogen filling valve

3. Primary terminal

4. Collar

5. Porcelain insulator

6. Primary conductor with insulation

7. Adaptor cylinder

8. Secondary cores

9. Base

10. Oil drain plug

Full Range of HV Technologies

Current Transformers (Paper/Oil) up to 420 kV - ITT 245

- IT 400

Hair-Pin design

IT 400 Cross section

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> Instrument Transformers - (ITR)- RMK Site - December 200548 48

Hair-Pin DesignTechnical Data

Rated voltage : 245 to 420 kV

Technology : Hair-Pin

Expansion device : Nitrogen

Rated primary current : up to 3000

Short circuit current : - 40 kA 1” (245 kV)

- 60 kA 1” (420 kV)

Total weight (kg)

kV 245 420

kg 1400 2300

ITT range

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> Instrument Transformers - (ITR)- RMK Site - December 200549 49

Classe Ratio errorat In

Phasedisplacementat In

Compositeerror atfL.IN

5 P 1 % 60 min. 5 %10 P 3 % 10 %

Current TransformersProtection accuracy

classesCEI 600 44-1CEI 600 44-1

Accuracy classes (Protection)Accuracy classes (Protection)Maximum current error in % of IP

Accuracy limit primary current = fL.IN

Burden :SN

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> Instrument Transformers - (ITR)- RMK Site - December 200550 50

Factors for Protection

Parameters

1. ALF ( accuracy limiting factor)

2. Composite error

Over Current and Earth Fault Protection

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> Instrument Transformers - (ITR)- RMK Site - December 200551 51

Factors for Protection

1. Accuracy Limiting Factor

What is Accuracy Limiting factor ?

It is the factor of over current above the rated current which determines the capability of CT to maintain the error at such a condition.

2. Composite error

It is the error of the CT when this over current is applied.

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> Instrument Transformers - (ITR)- RMK Site - December 200552 52

Composite error : Under steady-state conditions, the r.m.s. value of the difference between:a) the instantaneous values of the primary current, andb) the instantaneous values of the actual secondary current multiplied by the rated transformation ratio

CEI 600 44-1CEI 600 44-1

T

psnp

c dtiIKTI 0

2.1100

Current TransformersProtection accuracy classes

Kn is the rated transformation ratio;Ip is the r.m.s. value of the primary current;ip is the instantaneous value or the primary current;is is the instantaneous value of the secondary current;T is the duration of one cycle.

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> Instrument Transformers - (ITR)- RMK Site - December 200553 53

Factors for Protection

1. Accuracy Limiting Factor/composite error

For e.g if the class designation is 5P20

20 is the Accuracy limiting factor which signifies that when 20 times the rated primary current is applied the compositeerror of 5P( +/- 5%) is maintained.

Typical Class designations are

5P10, 5P20, 10P10, 10P20 etc.,

Page 54: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200554 54

Factors for Protection

Parameters

1. Knee Point Voltage requirement(Vk)

2. Exciting current ( Io)

3. Resistance of CT (Rct)

Transformer and Busbar Differential Protection

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> Instrument Transformers - (ITR)- RMK Site - December 200555 55

Current TransformersSaturation curve

10 20 30 40

InductionB [T]

Primary currentIp/In

Protection CT

18500 gauss

Metering CT

8000 gauss

Page 56: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200556 56

Factors for Protection

1. Knee Point Voltage(Vk):

Knee point voltage is point beyond which an application of 10% of voltage increases the exciting current by 50%.

The typical equations for Vk ( based on relay used)

Vk > 24 In (Rc t+2RL)- for Transformer Differential

Where In: Relay rated currentRL = Total lead ResistanceRc t = CT secondary resistance

Page 57: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200557 57

Current TransformersType Tests

IEC 600 44-1IEC 600 44-1

Type tests

a) short-time current tests

b) temperature rise test

c) lightning impulse test

d) switching impulse test

e) wet test for outdoor type transformers

f) determination of errors

Page 58: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200558 58

Current TransformerRoutine tests

CEI 600 44-1CEI 60-1

CEI 600 44-1CEI 60-1

Routine tests

The following tests apply to each individual transformers:

a) verification of terminal markings

b) power-frequency withstand test on primary winding

c) partial discharge measurement

d) power-frequency withstand test on secondary windings

e) power-frequency withstand tests, between sections

f) inter-turn overvoltage test

g) determination of errors

The order of the tests is not standardized, but determination of

errors shall be performed after the other tests.

Page 59: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200559 59

Typical ( Maximum) lead lengths based on voltage level of substations

Voltage Level in kV Lead Length in Meters

400 1000

220 800

132 500

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> Instrument Transformers - (ITR)- RMK Site - December 200560 60

Typical Burdens - Analog and Digital Meters( Current Transformer Circuit )

METERS/LOADS TYPICAL VABURDEN( ANALOG TYPE )

TYPICAL VA BURDEN( DIGITAL TYPE )

AMMETER 1 0.5

WATTMETER &VARMETER

1 0.1

ENERGY METER 1 0.1

PF METER 1 0.1

TRANSDUCER 1

TOTAL 5 1.8

Page 61: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200561 61

Typical Burden Calculation 400kV Current Transformer Metering core

The max burdens of all the meters/load = 5 VA (approx) considering analog meters and max lead length for 400kV switchyard = 1000 meters

The control cable size is 2.5 sq.mm. Always 2 runs of cable are used. Resistance of 2.5sq.mm cable is 8.5 ohms per kilometre for 2 runs of cable it is 4.25 Ohms

Therefore the burden of the lead length is = 2* isec2 * r * 1kM

= 2 *1*1* 4.25

= 8.5 VA

The optimum total burden will be = 5 + 8.5 = 13.5VA

Therefore realistic burden required is 15 or 20VA

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> Instrument Transformers - (ITR)- RMK Site - December 200562 62

Burden of numerical relay recommended = 2.5 VA ( inclusive of lead length ). The maximum lead length for 220/132kv switchyard = 500 meters

The control cable size is 2.5 sq.mm. Always 2 runs of cable are used. Resistance of 2.5sq.mm cable is 8.5 ohms per kilometre for 2 runs of cable it is 4.25 Ohms

Therefore the burden of the lead length is = 2* isec2 * r * 500/1000

= 2 *1*1* 4.25*0.5

= 4.25 VA

the optimum total burden = 2.5 +4.25 = 7 VA

Therefore realistic burden required for class 5P cores is 15 VA

NOTE: FOR 400KV CT's ONLY CLASS PS CORES NOTE: FOR 400KV CT's ONLY CLASS PS CORES ARE USED. HENCE THIS CALCULATION IS ARE USED. HENCE THIS CALCULATION IS OMITTED FOR 400KV CT’s.OMITTED FOR 400KV CT’s.

Typical Burden Calculation 220kV Current Transformer Protection core

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> Instrument Transformers - (ITR)- RMK Site - December 200563 63

List of utilities who have reduced burdens for metering of 0.2 accuracy Cl

CUSTOMER 400KV CT 220KV CT 132KV CT

APTRANSCO 20 ( 40 ) 20 ( 40) 15 ( 30)

PGCIL 20 ( 40) 20 ( 40) 20 ( 40 )

MSEB 20 ( 40) 20 ( 40 )

KPTCL 20 ( 30) 20 ( 30) 20 ( 30 )

RRVPNL 30 ( 40)

VALUES WITHIN BRACKET INDICATES PREVIOUS VALUES SPECIFIED

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Capacitor Voltage TransformersCCV range

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> Instrument Transformers - (ITR)- RMK Site - December 200565 65

1. Oil level indicator (optional)2. Expansion device3. Capacitor units4. Insulating oil5. Porcelain insulator6. Sealing7. Electromagnetic unit8. Low voltage terminals box/

HF terminal9. Series inductance10. Medium voltage transformer11. Damping circuit against ferroresonance effects

Capacitor Voltage Transformers (Paper/Film/Oil) up to 765 kV

CCV range

Full Range of HV Technologies

123

4

5

7

89

11

6

10

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> Instrument Transformers - (ITR)- RMK Site - December 200566 66

Accurate Measurement of HV

Capacitor Voltage Transformers Coupling Capacitors CCV / CC 72.5 to 765 kV

Line protection

HF transmission

Compliance with IEC, ANSI or equivalent standards

Reduce the slope of the RRRV (Rate of Rise of Recovery Voltage (Ik >40 kA)

Performance:

72.5 to 765 kV

Cn from 2.500 to 20.000 pF

Thermal capacity up to 1000 VA

Page 67: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200567 67

Accurate Measurement of HV

Capacitor Voltage TransformersCoupling Capacitors CCV / CC 72.5 to 765 kV

Characteristics:

Capacitor elements are made of paper-polypropylene and aluminum foils, insulated with synthetic dielectric oil

Up to four secondary windings

Carrier accessories (transmission from 30 up to 500 kHz) on request

Oil expansion by metallic bellows

Page 68: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 200568 68

Accurate Measurement of HV

Capacitor Voltage TransformersCoupling Capacitors CCV / CC 72.5 to 765 kV

Advantages:

Built-in safety features

Hermetically sealed for long life

Mineral & synthetic oil-filled, PCB free

Non-corrosive hardware

High reliability and longevity due to optimized design

Operation as coupling capacitors for power line carrier transmission

Superior transient response

Compact design : smaller diameter porcelain that results in less oil and less weight

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> Instrument Transformers - (ITR)- RMK Site - December 200569 69

Capacitor Voltage Transformers - CCV Range

Thousands of installed units attest to their reliability

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> Instrument Transformers - (ITR)- RMK Site - December 200570 70

Capacitor Voltage TransformerDefinitions

Element Pack(or pack)

Element Pack(or pack)

Pile of elements : ± 10 to 25 kV

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> Instrument Transformers - (ITR)- RMK Site - December 200571 71

Capacitor Voltage TransformerDefinitions

Assembly of elements in an insulating container: ± 245 kV.Can be connected to a HV line

Capacitor Unit(or unit)

Capacitor Unit(or unit)

HV Power line

Ground

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> Instrument Transformers - (ITR)- RMK Site - December 200572 72

Capacitor Voltage TransformerDefinitions

Capacitor STACK(or stack)

Capacitor STACK(or stack)

Assembly of elements to reach higher voltage levels : ± 800 kV

HV Power line

Ground

In general, the termCAPACITOR

stands for a capacitor elementas well as a capacitor stack.

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> Instrument Transformers - (ITR)- RMK Site - December 200573 73

Capacitor Voltage Transformer

Definitions

Capacitor Voltage Divider( or CVT )

Capacitor Voltage Divider( or CVT )

Connecting an MV inductive voltage transformer to a tap.

HV Power line

Ground

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> Instrument Transformers - (ITR)- RMK Site - December 200574 74

IntermediateVoltage :

10 to 20 kV/3

Capacitor Voltage TransformerBasics

S1

S2

P1

P2

C1

C2

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> Instrument Transformers - (ITR)- RMK Site - December 200575 75

Lµ = Inductance equivalent to magnetic losses of the magnetic circuit.

Rw = Resistance equivalent to the watt losses of the magnetic circuit.

Lfs = Secondary leakage inductance of the magnetic VT.

Rs = Resistance of the secondary winding

Capacitor Voltage TransformerMagnetic Transformer

Ce La LfsRa Rs

Lμ Rw ZcUsU’P =Vp . C1

k . (C1+C2)

Equivalent DiagramEquivalent Diagram

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> Instrument Transformers - (ITR)- RMK Site - December 200576 76

RMK - CVT

Capacitor stack

Inductive VT

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> Instrument Transformers - (ITR)- RMK Site - December 200577 77

CCV 72.5 to 765 kV

Capacitor elements

Capacitor column

Insulating oil

Insulator flange

Secondary terminal box

Inductance

MV Transformer

Oil expansion device

Damping circuit

RMK - CVTRMK - CVT

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> Instrument Transformers - (ITR)- RMK Site - December 200578 78

P

Capacitor Voltage TransformerDiagram

P

GROUND

GS HF

HV Terminal

C1

C2

N

4a

4n

111214

1a

1n

111214

2a

2n

111214

3a

3n

111214

MCB

S S S SGS MV D

L

HFDC

C

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> Instrument Transformers - (ITR)- RMK Site - December 200579 79

PLC System

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> Instrument Transformers - (ITR)- RMK Site - December 200580 80

Capacitor Voltage TransformerNew Capacitor Elements

All Paper Dielectric design Mixed dielectric design(New)

Paper PPR film + paper

Copper tabs forconnection

Aluminum foilfolded for contactwith next element

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> Instrument Transformers - (ITR)- RMK Site - December 200581 81

Capacitor Voltage TransformerNew Capacitor Elements

No more soldering

Improved contact between elements

No copper tabs

Improvements in the new designImprovements in the new design

Aluminum foil :

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> Instrument Transformers - (ITR)- RMK Site - December 200582 82

Capacitor Voltage TransformerNew Insulating "Oil"

Comparison between NEW JARYLEC and MINERAL OILSI.NO. Property Unit Mean value

Before treatment After treatmentmineral oil Jarylec mineral oil Jarylec

1 Colour transparent slightly yellow transparent slightly yellow2 Density at 29.50C g/cm3 0.89 0.99 0.89 0.99

3 Kinematic viscosity at 270C Cst 27 4.2 27 4.2

4 Interfacial tension at 270C N/m 0.04 0.036 0.04 0.036

5 Flash point 0C 140 144 140 144

6 Pour point 0C -6 <-50 -6 <-507 Acidity mgKOH/g 0.03 <0.01 0.03 <0.018 Breakdown voltage kV 30 >70 >60 >80

9Dielectric dissipation factor (tan) at

900°C<0.005 <0.004 <0.002 <0.001

10 Water content ppm 50 <100 15 511 Resistivity 1000C hmxcm 0.15x1012 >9x1014 0.35x1014 >9x1014

Very high breakdown voltage

High volume resistivityVery low viscosityfor better impregnation

Low loss angle

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> Instrument Transformers - (ITR)- RMK Site - December 200583 83

Capacitor Voltage TransformerNew Insulating "Oil"

Nature of the dielectric (impregnated)all paper/mineral oil Paper +PPR/Jarylec

under rated voltage 12.2 V/m 25 V/munder power frequency voltage 40 V/m 80 V/m

Maximal gradient

dielectricThicknesselementsN

columnUGradients

.)(

)(

The elements as per the new design can withstand double gradients.

Higher gradients allowed

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> Instrument Transformers - (ITR)- RMK Site - December 200584 84

Capacitor Voltage TransformerNew Insulating "Oil"

Maximalvoltage for "All paper"/mineral oil Paper + PPR/Jarylecan element 1050 V 1500 V

Nature of the dielectric

columntheinelementsofNumber

UU m

elementi .....

7.0/max

The elements as per the new design can withstand a higher voltage

Improved gradient results in smaller capacitorsSAME HEIGTH BUT SMALLER DIAMETER

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> Instrument Transformers - (ITR)- RMK Site - December 200585 85

During HF communication, earthing of signals or entry into magnetic part must be avoided.

Capacitor Voltage TransformerPLC system

P2

C1

C2

Line trap

InductivePart

HV line

Draining coil and grounding switchcould already be included in HF generator.

HF

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> Instrument Transformers - (ITR)- RMK Site - December 200586 86

cos.

.

1-.sin..

2V

VA3440.=

s

minutos)(en

ea CLR

Phase error :

sin.

.

1-.+cos..

2V

VA100.=%)(en

s ea CLR

Ratio error :

Reduce nominal secondary burden

Capacitor Voltage TransformerMagnetic Transformer

Accuracy at nominal frequencyAccuracy at nominal frequency

Good quality of windings

Good tuningHigh intermediate voltage

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> Instrument Transformers - (ITR)- RMK Site - December 200587 87

Ce La Rp

Lµ Rw

Rs

Rpam

Lam

Ram

ZcVsVi

Primary Short Circuit & Transient Response

Primary Short Circuit & Transient Response

Capacitor Voltage TransformerDamping Circuit

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> Instrument Transformers - (ITR)- RMK Site - December 200588 88

• In steady state, the CVT secondary voltage is a reliable representation of the primary voltage.

• In case of sudden change in the primary voltage (like a short circuit), the voltage output will be distorted (high error) during a few cycles.

• The above transient error will depend on:• The burden connected to the CVT• The moment of the voltage interruption.

• The transient response will be improved by adding a damping circuit connected on the secondary

Capacitor Voltage TransformerDamping Circuit

Primary Short Circuit & Transient ResponsePrimary Short Circuit & Transient Response

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> Instrument Transformers - (ITR)- RMK Site - December 200589 89

Short-circuit at zero crossing

Primary voltage

Secondary voltage

t

Vs

Vi

t

Capacitor Voltage TransformerDamping Circuit

Primary Short Circuit & Transient ResponsePrimary Short Circuit & Transient Response

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> Instrument Transformers - (ITR)- RMK Site - December 200590 90

Capacitor Voltage TransformerDamping Circuit

Short-circuit at zero crossing

Primary voltage

Secondary voltage

t

Vs

Vi

t

5%

10%

Secondary error

t

0 100 200 300 [ms]

Necessary to add a damping circuitNecessary to add a damping circuit

20 msIEC 186 error limits

IEC today :max 10% after 20ms

Primary Short Circuit & Transient ResponsePrimary Short Circuit & Transient Response

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> Instrument Transformers - (ITR)- RMK Site - December 200591 91

R R-L-C R-L-RHow to solve transient problems :

• High burden

• jeopardize accuracy

• High burden

• jeopardize accuracy

• Efficient• Easy to design

• Expensive

• Efficient• Easy to design

• Expensive

• Efficient• Sophisticated design

• Economical

• Efficient• Sophisticated design

• Economical

Capacitor Voltage TransformerDamping Circuit

Primary Short Circuit & Transient ResponsePrimary Short Circuit & Transient Response

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> Instrument Transformers - (ITR)- RMK Site - December 200592 92

Primary Short Circuit & Transient ResponsePrimary Short Circuit & Transient Response

-200

-100

0

100

200

30

0

35

0

40

0

45

0

50

0

55

0

60

0

Tension secondaireSecondary Voltage

-2

-1

0

1

2

3

4

5

6

7

30

0

35

0

40

0

45

0

50

0

55

0

60

0

% Erreur secondaire (transitoire)% error at secondary

R-L-RR-L-R

Capacitor Voltage TransformerDamping Circuit

-200-150-100-50

050

100150200

30

0

35

0

40

0

45

0

50

0

55

0

60

0

Tension primairePrimary Voltage

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> Instrument Transformers - (ITR)- RMK Site - December 200593 93

a) After clearance of a short-circuit at the secondary terminals (fuse blown) , the CVT being energizedat 120% of the rated voltage, the crest value of the secondary voltage must return to less than 10% error after 10 cycles.

b) After short-circuit clearance, at 150% of the rated voltage, the ferroresonnance must be eliminated within less than 2 seconds

Ferroresonance according IEC 186

Capacitor Voltage TransformerFerroresonance

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> Instrument Transformers - (ITR)- RMK Site - December 200594 94

Capacitor Voltage TransformerFerroresonance

L1

L2

ZN2

N1

Ith

C2

C1

SGC

CSecondary Short CircuitSecondary Short Circuit

L

R2

R1

D

FerroresonanceDamping deviceon inductive PT

L'1

L'2

RL SGL

FerroresonanceDamping deviceon inductance

"Transformer type"compensating

inductance

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> Instrument Transformers - (ITR)- RMK Site - December 200595 95

Secondary current

Secondaryvoltage

Withoutdampingdevice

Short-circuit

Fuseoperation

Capacitor Voltage TransformerFerroresonance

Primary voltage

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> Instrument Transformers - (ITR)- RMK Site - December 200596 96

-100-80-60-40-20

020406080

100

35

0

40

0

45

0

50

0

55

0

60

0

65

0

70

0

75

0

Secondarycurrent

-600

-400

-200

0

200

400

600

350

400

450

500

550

600

650

700

750

Secondary voltage

Withdampingdevice

Capacitor Voltage TransformerFerroresonance

-250-200-150-100-50

050

100150200250

35

0

40

0

45

0

50

0

55

0

60

0

65

0

70

0

75

0

Primaryvoltage

10 cycles : error < 10%

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> Instrument Transformers - (ITR)- RMK Site - December 200597 97

Voltage TransformersMetering Accuracy Classes

Accuracy classes - Multiple windingsSame conditions except, accuracy to be garanteed with- Other windings loaded between 0% to 100%

IEC 600 44-2IEC 600 44-2

REMEMBER : with multiple secondaries, the maximum possible burden will generally be limited by :- the possible burden in the highest accuracy class with 1 winding- the difference between the different burdens- the mutual influence of the secondaries

Ex.: Accuracy VA max Total VA to be sharedClass if 1 secondary between the 2 windings 0.2 250 VA 250 x 0.8 = 200 VA0.5 800 VA max. total simultaneous

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> Instrument Transformers - (ITR)- RMK Site - December 200598 98

ExcessiveFrequencyVariations

Nominal burdenOVER-ESTIMATEDReal load < 25% VAN

Nominal burdenUNDER-ESTIMATEDReal load > 100% VAN

Capacitor Voltage TransformerTypical Error Curve

Typical graph of variation of errors with VA & frequencyTypical graph of variation of errors with VA & frequency

Phase error

Ratio error

f

25% VA

f+f

f -f100% VA

+20’- 20’

+0.5

- 0.5

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> Instrument Transformers - (ITR)- RMK Site - December 200599 99

Voltage transformersProtection accuracy

classes

IEC 600 44-2IEC 600 44-2

Accuracy classes (Protection)Maximum error in % of VP

- Voltage between 5 % and fT x VNP

- Burden between 25% and 100% of SN

- Maximum error doubled for VNP=2%

Accuracyclass

Voltage(ratio)error

Phasedisplacement[minutes]

Cl 3P 3 % 120

Cl 6P 6 % 24O

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> Instrument Transformers - (ITR)- RMK Site - December 2005100 100

Capacitor Voltage TransformersRoutine tests (IEC 60044-5)

Routine tests

The following tests apply to each individual transformer:

a) Verification of terminal markings

b) Power-frequency withstand tests on primary windings

c) Partial discharge measurement

d) Power-frequency withstand tests on secondary

windings

e) Power-frequency withstand tests between sections

f) Determination of errors.

G) Ferroresonance test

h) Sealing test

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> Instrument Transformers - (ITR)- RMK Site - December 2005101 101

Capacitor Voltage TransformersType tests (IEC 60044-5)

a) Temperature-rise test

b) Short-circuit withstand capability test

c) Lightning impulse test

d) Switching impulse test

e) Wet test for outdoor type transformers

f) Determination of errors.

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> Instrument Transformers - (ITR)- RMK Site - December 2005102 102

Typical Burdens - Analog and Digital Meters (Voltage

Transformer Circuit )

METERS/LOADS TYPICAL VABURDEN( ANALOG TYPE )

TYPICAL VA BURDEN( DIGITAL TYPE )

VOLTMETER 5 1

WATTMETER&VARMETER

4 0.1

ENERGY METER 1 0.1

PF METER 4

ELECTRONICSYNCHROSCOPE

6

FREQUENCYMETER

7 1

TRANSDUCER 1

TOTAL 28 12.2

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> Instrument Transformers - (ITR)- RMK Site - December 2005103 103

MAXIMUM BURDEN IMPOSED ON THE CAPACITOR VOLTAGE TRANSFORMER METERING WINDING IN A 400KV SUBSTATION

The max burdens of all the meters/load = 28 VA (approx) when analog meters are considered and max lead length for 400kv switchyard = 1000 meters

The control cable size is 2.5 sq.mm. Always 2 runs of cable are used. Resistance of 2.5sq.mm cable is 8.5 ohms per kilometre for 2 runs of cable it is 4.25 Ohms

Therefore the burden of the lead length is = 2* isec2 * r * 1km

= 2 * (28/63.5)2* 4.25*1

= 1.70 VA

The optimum total burden = 28 +1.7 = 29.7 VA

Therefore realistic burden required is 50 VA

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> Instrument Transformers - (ITR)- RMK Site - December 2005104 104

Line Traps

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> Instrument Transformers - (ITR)- RMK Site - December 2005105 105

Features of AREVA T&D Line Traps Design

High short-circuit withstand capability

Light weight

Reliable open-style design (OSD)

Mounting flexibility

Excellent cooling

Extremely reliable tuning devices

Self-resonance frequency greater than 500 kHz

Maintenance-free design

No surface cracking

Page 106: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 2005106 106

Corona Ring

Protective Device

Tie Rod

Main Coil

Tuning Device

PedestalBird Barrier

Crossarm

Terminal

Terminal

Lifting Lug

Line TrapsConstruction

Main Components

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> Instrument Transformers - (ITR)- RMK Site - December 2005107 107

Line TrapsMounting Arrangements

Vertical pedestal Horizontal pedestal Suspension

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> Instrument Transformers - (ITR)- RMK Site - December 2005108 108

Line TrapsMounting Arrangements

Lifting lug bolted to the central tie rod

Eyebolt to the bottom crossarm

One to four-point suspension

Suspension mounting

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> Instrument Transformers - (ITR)- RMK Site - December 2005109 109

Line TrapsMounting Arrangements

Vertical pedestal mounting type “A”

Aluminum pedestal

Small or medium sized LT can be mounted directly on a single post insulator or CCVT

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> Instrument Transformers - (ITR)- RMK Site - December 2005110 110

Line TrapsMounting Arrangements

Vertical pedestal mounting type “B”

Aluminum pedestal

Large sized LT: 3 insulator column pedestal

Number of columns can be adapted

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Line TrapsMounting Arrangements

Aluminum or stainless steel pedestal

Horizontal mounting (for OSD)

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> Instrument Transformers - (ITR)- RMK Site - December 2005112 112

Line TrapsMain Components

Easily accessible and exchangeable:

can be replaced without removing the

line trap from the line.

Factory fixed or field adjustable.

For single-frequency, double-

frequency,

or wide-band tuning

Areva tuning device can be used in all

existing LT

Tuning Device Options

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> Instrument Transformers - (ITR)- RMK Site - December 2005113 113

Line TrapsMain Components

Connected across the main coil and the tuning device to prevent the LT from being damaged by transient over-voltages.

Surge Arrester

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> Instrument Transformers - (ITR)- RMK Site - December 2005114 114

Bird Barrier

Line TrapsMain Components

Temperature and UV resistant fiberglass reinforced plastic grid with square shaped 15 X 15 mm openings

Cooling of the line traps remains unchanged.

Bird Barrier

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> Instrument Transformers - (ITR)- RMK Site - December 2005115 115

Line TrapsBasic Design Parameters

Standard

System voltage

Rated frequency

Rated inductance

Rated current

Blocking range

Minimum blocking impedance or resistance

Short-circuit requirements

Type of mounting

Site conditions

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> Instrument Transformers - (ITR)- RMK Site - December 2005116 116

Condenser Bushings

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> Instrument Transformers - (ITR)- RMK Site - December 2005117 117

Full Range of HV Technologies

Condenser bushings - Oil to air- Oil impregnated paper (OIP)

Suitable for connecting outdoor equipment to HV transformers as per ANSI or IEC standard

Air side : porcelain envelope

Partial discharge < 5pC at 1.5Un /

Specially treated mineral oil

Power factor tap, air draining plug and oil side shield provided

Prismatic oil sight glass with option MOLG above 145kV

Flange of aluminum alloy casting

Extensive field experience

High creepage bushing on request

Dielectric dissipation factor < 0.40%

3

Up to 420 kV

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> Instrument Transformers - (ITR)- RMK Site - December 2005118 118

Full Range of HV Technologies

In addition to bushings for power transformers, AREVA T&D also manufactures wall bushings, oil-oil bushings and high current bushings.

Page 119: Presentation on All Products With Detailed CCV and CT

> Instrument Transformers - (ITR)- RMK Site - December 2005119 119

1. Top terminal

2. Cable bolt

3. Oil filling plug

3a . Nitrogen filling plug

4. Expansion bowl

5. Oil sight glass

6. Springs

7. Gaskets

8. Central metal tube

9. Oil impregnated core

10. Porcelain - Upper

11. Fixing flange

12. Test tap

13. Air releasing screw

14. Porcelain -Lower

15. Base plate / stress shield

16. Upper arcing horn

17. Lower arcing horn

18. Top shield cover

19. Bolt and nut

Full Range of HV Technologies

Condenser Bushings

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> Instrument Transformers - (ITR)- RMK Site - December 2005120 120

Assembled Bushings

Page 121: Presentation on All Products With Detailed CCV and CT

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