Fibres on OHL_rowland

8/7/2019 Fibres on OHL_rowland

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1.1

Optical Fibres on Overhead Lines

EEPS 05

TRANSMISSION & DISTRIBUTION

PLANT

Dr Simon Rowland


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1.2

Products

OPGW, Optical ground wire

Wrap on phase or ground wire

Lash on phase or ground wire

MASS, Metallic self supporting

ADSS, All dielectric self supporting

OPPC, Optical Phase conductor

There are fewer options if bundled

conductors are present

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1.3

Fibre and cable system protection Moisture

Vibration (Aeolian)

External Mechanical Forces Installation

Service

Gunshot

Strain Wind and ice loading

Extreme Temperature Exposure Changes in ambient

Short circuit conditions

Lightning

Electrical


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Loose tube stranding

Helical stranding

SZ stranding

SZReversal point


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Tubing/Buffering Strain windowFibreStrain

-

+

CableStrain

+

Elongation

+0.5%-0.5%-

Contraction

Cable StrainWindow of 1% for

Fibre Strain=0%

Fibres touch

inside wallof tubesmicrobending

Fibres on

neutral axisof tubes

Fibres

touchouter wallmicrobending


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Tubing/BufferingWhat happens to attenuation?

CableStrain

+-

ElongationContraction

+0.5%-0.5%

Addedloss


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OPGW

Optical ground wire


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OPGW (Optical Ground Wire) OPGW replaces ground wire

Strength and electrical conductivity provided by metallic

strands: galvanised steel

Al-coated steel

Al alloy or Al

OPGW designed to have similar mechanical and thermalexpansion properties to cable it replaces

Strands are greased to prevent corrosion: 2 or 3 layers oftenused

At the rated fault current, optical cable temperature does notrise high enough to damage the optical core

Wire size chosen to resist lightning damage


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1.10

Fibral OPGW Design

Steel, Al, ACS wires

Aluminium C-section

Inner sheath

MDPE CSM


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1.11

Al or Al-Clad Steel wires

Galvanised Steel wires

Fibre in Steel Tubeelements

OPGW: Fibre in Steel Tube Fibres placed in laser-welded steel tube

Steel tubes never in external strand


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1.12

OPPC

Optical phase conductor


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1.13

Optical Phase Conductor (OPPC)

Same Cable Technology as OPGW Replaces one of the Phase Conductors

Special Fittings required to bring cablefrom Phase to Ground

Systems installed up to 150kV to date

Higher Voltages possible


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1.14

33kV OPPC system


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1.15

ADSS

All dielectric self supporting cable


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1.16


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1.17


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1.18


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1.19

In all cases aramid yarns provide the strength

Often the outer jacket is of a special tracking resistant material

Cable is non-metallic, may be installed on live system, reducinginstallation cost significantly

Also used as temporary repair

ADSS Cable Design

StrengthMember

InnerSheath

OuterSheath

Tape

wrap

Polyest

er filler

Loose BufferTubeOptical

Fibre

StengthMember


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1.20


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1.21

ADSS LIMITATIONS

Cable sits in Potential Field (between phases)

Induced Current on Cable Sheath

DRY BAND ARCING threat to cable integrity

In severe cases damages cable strengthmember


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1.22

Fields on ADSS

Clamp

Phase Conductor

Optical Cable

x


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1.23

Currents on ADSS

Volts

Current

zone 1 - 50mzone 1 - 50m


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1.24

DRY BAND ARCING

Moisture/Pollution

CABLE

Support

at Tower (Earth)

ARC

DRY BAND


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1.25

Wrap and lash


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1.26

Wrap and lash cable design

Up to 48f

Installed if earthwire replacement unlikely forseveral years

Installation rate: up to 20 km/week Live line application possible

Design to cope with short-circuit currents;

lightning; bird-peck & shotgun Cannot withstand severe mechanical attack

such as large birds and heavy shot


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1.27

Standard design :

Outer diameter 5.9 / 6.5 mm

Cable weight 28 / 34 kg/km

Fiber count up to 48

Standard design :

Outer diameter 5.9 / 6.5 mm

Cable weight 28 / 34 kg/km

Fiber count up to 48

Wrap cable Lash Cable


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1.28

Radio controlled lashing machineManual lashing machine

Lightweight installation machines

Easy transportation and transfer at the towers Extremely fast installation with helicopter support

Live-line installation

Lash Installation Technology

Helicopter support


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1.29


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1.30

Accessories : Tower Bypass The temporarily secured cable is routed

round the tower using a curved support and isthen secured permanently

Angledsupport tube

Cable

Tower bypass on C-framewith curved support + cable

Ground wire

Cable wrappedaround guide rod


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1.31


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1.32

Testing

Tensile

Vibration

Sheave

Lightning

Short circuit

Corrosion


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1.33

New LineorReplacement of Conductors

on Existing Line

No Groundwire

OPGWOPGW

Existing LineandNo Need for Replacement

of Conductors

OPPCOPPC

Groundwire

Lash or wrap

onPhase conductor

Lash or wrap

onPhase conductor

No Groundwire

Lash or wrapLash or wrap

ADSS or MASSADSS or MASS

Groundwire

Conclusion - The Choice

Documents

Fibres on OHL_rowland