CIGRE SC B2 Overhead linesOverhead lines TUTORIAL ... 2011/Umberto - SPACER TUTORIAL CIGRE 20… · CIGRE SC B2 Overhead linesOverhead lines TUTORIAL PRESENTATION ON SPACERS AND SPACER

CIGRE SC B2CIGRE SC B2Overhead linesOverhead linesOverhead linesOverhead lines

TUTORIAL PRESENTATION ON SPACERS TUTORIAL PRESENTATION ON SPACERS AND SPACER DAMPERSAND SPACER DAMPERS

bby Umberto Cosmaiy Umberto CosmaiConvenor Convenor WG B2.25WG B2.25

Based on the Technical Brochure TB277 prepared Based on the Technical Brochure TB277 prepared by Cigre SCB2 WG11by Cigre SCB2 WG11--TF5 August 2005TF5 August 2005

Study Committee B2 - Technical Advisory Group B2-AG-06

Spacer and spacer damper primary task is to Spacer and spacer damper primary task is to maintain the geometry of conductor bundles, maintain the geometry of conductor bundles, g y ,g y ,

within the design limits, under the normal within the design limits, under the normal service conditions.service conditions.

Spacer and spacer damper shall withstand the Spacer and spacer damper shall withstand the h i l l d i d d i i t ll tih i l l d i d d i i t ll timechanical loads imposed during installation, mechanical loads imposed during installation,

maintenance and service, including short circuits, maintenance and service, including short circuits, without failures and without damaging thewithout failures and without damaging thewithout failures and without damaging the without failures and without damaging the

conductors.conductors.


CONDUCTOR BUNDLESCONDUCTOR BUNDLES

TwinTwin bundlesbundles 150150--500 kV500 kVTwin Twin bundlesbundles 150150 500 kV500 kVSpacing: 320Spacing: 320--600 mm600 mm(most used 400(most used 400--450450--457mm)457mm)

Triple and quad bundles Triple and quad bundles Voltage: 380Voltage: 380--800 kV800 kVSpacing: 320Spacing: 320--600 mm600 mmp gp g(most used 400(most used 400--450450--457mm)457mm)

Six and eight conductor bundlesSix and eight conductor bundlesSix and eight conductor bundles Six and eight conductor bundles Voltage: 800Voltage: 800--1000 kV1000 kVSpacing: 320Spacing: 320--400 mm400 mm( t d 320( t d 320 400 )400 )


(most used 320(most used 320--400mm)400mm)

E d d b dlExpanded bundles

850

1450

1450

Used in Russia and Brazil to increase the power capacity of a

transmission systems900


transmission systems

I l i h d i bI l i h d i bIn relation to the design, spacers can be In relation to the design, spacers can be classified as follows:classified as follows:

Rigid spacersRigid spacers

S iS i i idi idSemiSemi--rigid spacersrigid spacers

Articulated spacersArticulated spacerspp

Flexible spacersFlexible spacers

Spacer dampersSpacer dampers


Rigid spacersRigid spacersDo not allow any significant relative movements Do not allow any significant relative movements

and displacements of the suband displacements of the sub--conductorconductor

Rigid spacersRigid spacers

and displacements of the suband displacements of the sub conductorconductor. .

Are used in jumper loops (where sometimes are Are used in jumper loops (where sometimes are t i ht d) d l k lt i ht d) d l k l


counterweighted) and slack spans only.counterweighted) and slack spans only.

SemiSemi rigid spacersrigid spacersSemiSemi--rigid spacersrigid spacers

Can accommodate small relative movements and static Can accommodate small relative movements and static di l t b t bdi l t b t b d td tdisplacements between subdisplacements between sub--conductorsconductors..

Are used in transmission lines in conjunction with Are used in transmission lines in conjunction with ib ti dib ti d


vibration dampers.vibration dampers.

Flexible spacersFlexible spacersFlexible spacersFlexible spacers

Allow large relative movements and static Allow large relative movements and static di l t b t bdi l t b t b d td tdisplacements between subdisplacements between sub--conductors.conductors.

Are used in transmission lines in conjunction Are used in transmission lines in conjunction with vibration dampers.with vibration dampers.


with vibration dampers.with vibration dampers.

A ti l t dA ti l t dArticulated spacersArticulated spacersAllow large relative movement and static displacements Allow large relative movement and static displacements

b t bb t b d t i di tid t i di tibetween subbetween sub--conductors in one or more directions.conductors in one or more directions.

Are used in conjunction with vibration dampersAre used in conjunction with vibration dampers..


Spacer dampersSpacer dampersSpacer dampersSpacer dampersAre spacing devices whose inertial, elastic and damping Are spacing devices whose inertial, elastic and damping

properties are defined and coordinated to mitigate aeolian properties are defined and coordinated to mitigate aeolian p p gp p gvibration.vibration.

They can also accommodate relative movements and staticThey can also accommodate relative movements and staticThey can also accommodate relative movements and static They can also accommodate relative movements and static displacements between subdisplacements between sub--conductors in any direction.conductors in any direction.

Except for special cases, they do not require the Except for special cases, they do not require the li ti f ib ti dli ti f ib ti d


application of vibration dampers.application of vibration dampers.

SPACER CLAMPSSPACER CLAMPSSPACER CLAMPSSPACER CLAMPS

The spacer and spacer damper clamps are generally made The spacer and spacer damper clamps are generally made of primary aluminium alloy. They shall:of primary aluminium alloy. They shall:

Maintain a suitable grip for the whole life of the line and inMaintain a suitable grip for the whole life of the line and inMaintain a suitable grip for the whole life of the line and in Maintain a suitable grip for the whole life of the line and in the whole range of service temperaturethe whole range of service temperature..

Avoid any conductor damage during installation and Avoid any conductor damage during installation and service. service.

Be free from Corona and RIV at the maximum line voltage.Be free from Corona and RIV at the maximum line voltage.


Be installed without disassembling of any partsBe installed without disassembling of any parts

Be designed to minimize the the chance of Be designed to minimize the the chance of mismis--installation.installation.

Be capable of being safely removed and reBe capable of being safely removed and re--installed on the installed on the conductors. conductors.

Allow installation survey from the groundAllow installation survey from the ground..

Ensure that individual components will not become loose Ensure that individual components will not become loose in service. in service.


Types of spacer clampyp p pCantilever single-bolted

Nut cracker single boltedNut-cracker single-bolted

Cantilever single-bolted, rubber-lined

Nut-cracker rubber-lined, with latch fastener

Open clamp rubber lined, with helical rods

O l bb d ith h li l dOpen clamp rubber covered, with helical rods

Nut-cracker spring loaded


p g

Cantilever clampCantilever clamp


Nut cracker clampNut cracker clamp


R bb li d lR bb li d lRubber lined clampsRubber lined clamps

Cantilever bolted typeCantilever bolted typeCantilever bolted typeCantilever bolted type

N tN t kk ith l t hith l t hNutNut--crackercracker with latch with latch fastenerfastener


H li llH li ll tt h d ltt h d lHelicallyHelically--attached clampattached clamp

rubber lined typerubber lined type


H li llH li ll tt h d ltt h d lHelicallyHelically--attached clampattached clamp

rubber covered typerubber covered type


Coil spring loaded clampCoil spring loaded clampCoil spring loaded clampCoil spring loaded clamp

Used mainly in JapanUsed mainly in Japan


Comparison between cantilever and nut cracker clampsComparison between cantilever and nut cracker clamps


Bolt fastenersBolt fastenersBolt fastenersBolt fasteners

HomogeneousHomogeneous

Bolt and nut, both made of galvanized Bolt and nut, both made of galvanized steel, or aluminium alloy or stainless steel, or aluminium alloy or stainless

steel. steel.

HeterogeneousHeterogeneousBolts of galvanized steel, aluminium Bolts of galvanized steel, aluminium

alloy and stainless steel engaged intoalloy and stainless steel engaged intoalloy and stainless steel, engaged into alloy and stainless steel, engaged into a threaded hole of the clamp bodya threaded hole of the clamp body..


AntiAnti--unscrewing elementsunscrewing elementsAntiAnti unscrewing elementsunscrewing elementsEnergy storing typeEnergy storing type

Belleville Belleville hh

Plain Plain hhwasherwasher washerwasher

The Belleville washer is a conical spring washer able to The Belleville washer is a conical spring washer able to compensate all the clamp relaxation due to, creep, embedment, compensate all the clamp relaxation due to, creep, embedment,

cold flow, etc.cold flow, etc.


,,A plain washer is used to support the Belleville washerA plain washer is used to support the Belleville washer. .

Anti-unscrewing elementsAnti-unscrewing elementsFriction types

Plastic Plastic patchpatch

Anti-unscrewing elements such as plastic patches or ring inserts are used on bolts and nuts to increase the thread

friction


friction.

AntiAnti--unscrewing elementsunscrewing elementsAntiAnti--unscrewing elementsunscrewing elementsLocking typeLocking type

Aluminium or stainless steel “safety plates” of various shapesAluminium or stainless steel “safety plates” of various shapesAluminium or stainless steel safety plates of various shapes Aluminium or stainless steel safety plates of various shapes can be installed just below the bolt head. can be installed just below the bolt head.

After tightening the bolt, the plate tabs are bent over against After tightening the bolt, the plate tabs are bent over against the bolt head to lock itthe bolt head to lock it


the bolt head to lock it.the bolt head to lock it.

Breakaway bolts and nutBreakaway bolts and nutBreakaway bolts and nutBreakaway bolts and nutThe upper head breaks away at the specified nominal torque. The upper head breaks away at the specified nominal torque.

No torque wrench is requiredNo torque wrench is requiredNo torque wrench is requiredNo torque wrench is required..

Are made in Are made in aluminium alloy or aluminium alloy or

stainless steelstainless steelstainless steelstainless steel

Best solutionBest solution


In alternative to breakaway bolts, zinc alloy break away In alternative to breakaway bolts, zinc alloy break away caps can be used on standard bolts caps can be used on standard bolts


Bolt head directed Bolt head directed upwardupward

This solution makes theThis solution makes theThis solution makes the This solution makes the installation easier but the installation easier but the

correct tightening of correct tightening of breakbreak--away bolts can not away bolts can not

be controlled from the be controlled from the ground ground gg


Bolt head directed downward

This solution makes the installation more difficult but is This solution makes the installation more difficult but is required when breakaway bolts are usedrequired when breakaway bolts are used


Helical rod attachmentHelical rod attachmentHelical rod attachmentHelical rod attachment

The helical rods, usually four per clamp, are made in aluminium The helical rods, usually four per clamp, are made in aluminium alloyalloy The rods distribute the clamp pressure on a relatively longThe rods distribute the clamp pressure on a relatively longalloy. alloy. The rods distribute the clamp pressure on a relatively long The rods distribute the clamp pressure on a relatively long

length of conductorlength of conductor

The rods shall have enough elasticity to apply a suitable grip The rods shall have enough elasticity to apply a suitable grip d t t d ti f d t di td t t d ti f d t di t


and to compensate any reduction of conductor diameter.and to compensate any reduction of conductor diameter.

S l t l d i d d/ i tlS l t l d i d d/ i tlSpacer clamps not properly designed and/or incorrectly Spacer clamps not properly designed and/or incorrectly installed, can get loose under the effect of conductor installed, can get loose under the effect of conductor

vibrationsvibrations

Conductor abrasion due to a slightly loosen clampConductor abrasion due to a slightly loosen clamp


Conductor abrasion due to a slightly loosen clampConductor abrasion due to a slightly loosen clamp

When the looseness increases the conductor strands are When the looseness increases the conductor strands are broken by the hammering of the clamp under the effect of broken by the hammering of the clamp under the effect of

conductor vibrationsconductor vibrationsconductor vibrations conductor vibrations


A heavy clamp may force a vibration node and produce fatigue A heavy clamp may force a vibration node and produce fatigue failure of the conductor strands at its locationfailure of the conductor strands at its location


SPACER DAMPERSSPACER DAMPERS


Twin Spacer DampersTwin Spacer Dampers


T i l S DT i l S DTriple Spacer DampersTriple Spacer Dampers


Q d S DQ d S DQuad Spacer DampersQuad Spacer Dampers


Diamond Spacer DampersDiamond Spacer Dampers


S d f i d b dlS d f i d b dlSpacer dampers for six conductor bundlesSpacer dampers for six conductor bundles


Spacer damper for eight conductor bundlesSpacer damper for eight conductor bundles


Spacer damper main partsSpacer damper main partsSpacer damper main partsSpacer damper main parts

internal internal stopstop

externalexternal

mainmain articulationarticulation

external external stopstop

main main frame or frame or central central

articulationarticulation

frameframe

clampclamp


clampclamp

SPACER DAMPER FRAMESPACER DAMPER FRAMESPACER DAMPER FRAMESPACER DAMPER FRAME

The central frame can be made of aluminium alloy, galvanized The central frame can be made of aluminium alloy, galvanized steel or cast iron. It shall:steel or cast iron. It shall:

Contain housings for the articulationsContain housings for the articulations..

Provide stops for the arm rotation. Provide stops for the arm rotation.

Develop suitable inertial forces.Develop suitable inertial forces.

With t d h t i it fWith t d h t i it fWithstands short circuit forces.Withstands short circuit forces.

Avoids audible noise induced by the wind.Avoids audible noise induced by the wind.


yy

SPACER DAMPER ARTICULATIONSPACER DAMPER ARTICULATION

The spacer damper articulations contain damping elements The spacer damper articulations contain damping elements generally made of elastomer. generally made of elastomer.

Most used elastomers are: Chloroprene (Neoprene) rubber, Most used elastomers are: Chloroprene (Neoprene) rubber, EPDM rubber, NBR rubber, silicon rubber and special EPDM rubber, NBR rubber, silicon rubber and special

dd


compounds.compounds.

Elastomers shall:Elastomers shall:

Have high hysteresis lossesHave high hysteresis losses..

Withstand the attack of ozone and UV radiation.Withstand the attack of ozone and UV radiation.

M i t i th ti i th h l f iM i t i th ti i th h l f iMaintain the properties in the whole range of service Maintain the properties in the whole range of service temperature.temperature.

Maintain the properties for the expected life of the line.Maintain the properties for the expected life of the line.


In relation to the number of articulations per arm, In relation to the number of articulations per arm, spacer dampers can be classified as follows: spacer dampers can be classified as follows:

Single articulationSingle articulation

Double articulationDouble articulation

The majority of modern spacer dampers are single The majority of modern spacer dampers are single ti l ti tti l ti t


articulation type.articulation type.

Damping mechanismDamping mechanismDamping mechanismDamping mechanism

The damping mechanism is based on the dissipation of the The damping mechanism is based on the dissipation of the bb d t ib tid t ib tisubsub--conductor vibration energy. conductor vibration energy.

The spacer damper extracts energy from the subThe spacer damper extracts energy from the sub--conductors conductors by means of the elastomer flexibleby means of the elastomer flexible damping elements used indamping elements used inby means of the elastomer flexibleby means of the elastomer flexible-- damping elements used in damping elements used in

the articulations.the articulations.

To do that the the spacer damper arms shall rotate allowingTo do that the the spacer damper arms shall rotate allowingTo do that the the spacer damper arms shall rotate allowing To do that the the spacer damper arms shall rotate allowing the elastomer to absorb energy by deformation.the elastomer to absorb energy by deformation.

Wh th b dl ib t ith l ti t b tWh th b dl ib t ith l ti t b tWhen the bundle vibrates with no relative movements between When the bundle vibrates with no relative movements between subsub--conductors, the main frame of the spacer damper shall conductors, the main frame of the spacer damper shall develop inertial forces able to determine arm rotations and develop inertial forces able to determine arm rotations and


consequently dissipation of energy.consequently dissipation of energy.

Inertial reactionInertial reaction

the inertial reaction of the central framethe inertial reaction of the central frameDuring subDuring sub--conductor aeolian vibrations, conductor aeolian vibrations,

ll t ti th di i ti fll t ti th di i ti f


allow arm rotation thus dissipation of energy allow arm rotation thus dissipation of energy

Spacer or spacer damper systemSpacer or spacer damper systemSpacer or spacer damper systemSpacer or spacer damper system

Is the complex of spacer units and the relevant scheme Is the complex of spacer units and the relevant scheme f di t ib ti l th lif di t ib ti l th liof distribution along the line.of distribution along the line.

The inThe in--span distribution is the main factor for the control ofspan distribution is the main factor for the control ofThe inThe in span distribution is the main factor for the control of span distribution is the main factor for the control of subsub--span oscillation. Damping capacity although not span oscillation. Damping capacity although not

detrimental is not required.detrimental is not required.

The distribution schemes consider unequal subThe distribution schemes consider unequal sub--spans spans (staggered scheme) to avoid transfer of oscillations (staggered scheme) to avoid transfer of oscillations ( gg )( gg )

between subbetween sub--spans and to limit the number of subspans and to limit the number of sub--spans spans oscillating simultaneously at a given wind speed. oscillating simultaneously at a given wind speed.


Quad bundles are more prone to oscillate than triple. Quad bundles are more prone to oscillate than triple. Twin and diamond bundles are the least critical.Twin and diamond bundles are the least critical.

The maximum subThe maximum sub--span length adopted in critical areas is span length adopted in critical areas is p g pp g paround 65m. around 65m.

I di i bI di i b f 80 h b df 80 h b dIn non severe conditions subIn non severe conditions sub--span of 80m have been used span of 80m have been used without problems. without problems.

Expanded bundles are not subjected to subExpanded bundles are not subjected to sub--span span oscillations and require less spacers than normal oscillations and require less spacers than normal

bundlesbundles


bundles.bundles.

The end subThe end sub--spans are kept shorter to prevent their spans are kept shorter to prevent their oscillation (that would damage the hardware) and to increase oscillation (that would damage the hardware) and to increase

the torsional stability of the bundle.the torsional stability of the bundle.

Sh t d bSh t d b l t ib t i ll t thl t ib t i ll t thShort end subShort end sub--spans also contributes marginally to the spans also contributes marginally to the prevention of galloping.prevention of galloping.

In cold Countries end subIn cold Countries end sub--spans length of 25spans length of 25--35 m are 35 m are considered suitable. considered suitable.

In hot Countries end subIn hot Countries end sub--spans length of 35spans length of 35--45 m have 45 m have been used. been used.


Spacer and spacer damper performanceSpacer and spacer damper performance

The spacer dampers control aeolian vibration by means of theirThe spacer dampers control aeolian vibration by means of theirThe spacer dampers control aeolian vibration by means of their The spacer dampers control aeolian vibration by means of their inherent damping capacity.inherent damping capacity.

Aeolian vibration can also be controlled by nonAeolian vibration can also be controlled by non--rigid spacers rigid spacers (semi(semi--rigid, flexible or articulated)and vibration dampers.rigid, flexible or articulated)and vibration dampers.

The spacers or spacer dampers control subThe spacers or spacer dampers control sub--span oscillation by span oscillation by means of a suitable inmeans of a suitable in--span distribution.span distribution.

Galloping can not be fully controlled by normal spacer and Galloping can not be fully controlled by normal spacer and spacer dampers. spacer dampers.


p pp p

Spacer dampers equipped with torsional dampers (one or two Spacer dampers equipped with torsional dampers (one or two per span) are used for controlling severe subspan oscillations.per span) are used for controlling severe subspan oscillations.p p ) g pp p ) g p

A pendulum arm connected to the spacer damper frame A pendulum arm connected to the spacer damper frame through a damping articulation can control subthrough a damping articulation can control sub--span oscillation span oscillation


mitigating the torsional vibration modes of the bundle mitigating the torsional vibration modes of the bundle

Spacer dampers equipped with detuning pendula are used for Spacer dampers equipped with detuning pendula are used for controlling galloping.controlling galloping.g g p gg g p g

Detuning pendula applied on spacer damper frames also Detuning pendula applied on spacer damper frames also improve the performance of these devices in controlling improve the performance of these devices in controlling

aeolian vibrations and subaeolian vibrations and sub span oscillationsspan oscillations


aeolian vibrations and subaeolian vibrations and sub--span oscillations.span oscillations.

I i l d d d bli i lI i l d d d bli i lInternational standard and publications relevant to International standard and publications relevant to spacers and spacer dampersspacers and spacer dampers

IEC 61854 St d d 1998IEC 61854 St d d 1998 0909IEC 61854 Standard 1998IEC 61854 Standard 1998--09 09

Overhead lines Overhead lines -- Requirements and tests for spacersRequirements and tests for spacers

CIGRECIGRE Technical brochure TB277 Technical brochure TB277 -- August 2005August 2005Prepared by SCB2 WG11Prepared by SCB2 WG11--TF5TF5State of the art survey on spacer and spacer dampersState of the art survey on spacer and spacer dampersState of the art survey on spacer and spacer dampers State of the art survey on spacer and spacer dampers Part 1 General descriptionPart 1 General descriptionPart 2 Technical aspectsPart 2 Technical aspectsP t 3 C t tiP t 3 C t tiPart 3 Current practicePart 3 Current practice

EPRI EPRI -- Transmission Lines Reference BookTransmission Lines Reference BookWind Induced Conductor MotionWind Induced Conductor Motion 20092009


Wind Induced Conductor Motion Wind Induced Conductor Motion -- 20092009

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CIGRE SC B2 Overhead linesOverhead lines TUTORIAL ... 2011/Umberto - SPACER TUTORIAL CIGRE 20… · CIGRE SC B2 Overhead linesOverhead lines TUTORIAL PRESENTATION ON SPACERS AND SPACER