Introduction to NSW

4-Nov-13 / 1

Optical Ground Wires

(OPGW) Presented by NSW (Norddeutsche Seekabelwerke GmbH)

Introduction to NSW

4-Nov-13 / 2

NSW – The Company

Plant Overview

Introduction to NSW

4-Nov-13 / 3

NSW Ground Wire History

Ground Wire Cables

production since 1960’s

Fiber Optic Ground Wire

cable production since 1980’s

More than 100 years experience in cable armoring

Our Experience

Introduction to NSW

4-Nov-13 / 4

NSW Ground Wire History

The History

NSW Ground Wire History and

Design Development

over more than 50 years

Copper Ground Wire Cables

Hybrid Electro / Optical Ground Wire Cable

OPGW with Stranded Steel Tube

FO - Central Plastic Tube

Central Aluminum Buffer Tube Design

Introduction to NSW

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NSW Ground Wire History

Copper Ground Wire Cables

Start of production early 60`s

Stranded copper star quads

(four wires)

Armoring wires (one and two layers)

PE-HD Jacket

Introduction to NSW

4-Nov-13 / 6

NSW Ground Wire History

OPGW with Stranded Steel Tube

Armoring wires (one and two layers)

Stranded FO single tubes (steel)

Introduction to NSW

4-Nov-13 / 7

NSW Ground Wire History

FO - Central Plastic Tube

FO - central Plastic tube

Armoring wires (one and two layers)

Introduction to NSW

4-Nov-13 / 8

NSW Designs

• high fiber counts

• small outer diameter

• high fiber excess length

• protective tube only

• low crush resistance

• additional weight

• careful installation

Fibers are placed in a stainless steel tube

tube in the center of the cable, protected by

one or more layers of armoring wires.

Central Buffer Tube Made of Stainless Steel

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NSW Standard OPGW Design

Central Aluminum Buffer Tube

• high protection against

mechanical and

electrical loads

• high fiber counts

• small outer diameter

• higher fiber excess length

• good thermal performance

• Limited outer diameter with

single layer design

Fibers are placed in a aluminum tube in the

center of the cable, protected by one or more

layers of armoring wires.

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NSW New Single Layer OPGW Design

Big Central Aluminum Buffer Tube with enhanced Wall Thickness

• highest protection against

mechanical and

electrical loads

• highest fiber counts

• small outer diameter

• higher fiber excess length

• Very good thermal advantage

• Limited outer diameter with

single layer design

Fibers are placed in a aluminum tube in the

center of the cable, protected by one layer of

armoring wires (mostly ACS).

X

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OPGW Design Criteria

Main reasons for NSW to investigate and develop

the aluminum central buffer tube design

1. Conductivity

2. Corrosion

3. Fiber excess length

4. Various diameters with single layer design reduce weight

5. Capability to use thicker ACS-Wires for better lightning

protection

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Conductivity

Sample: AA/ACS 41/41 with St-Tube

0 5 10 15 20 25 30 0

50

100

150

200

250

Time / s

Te

mp

era

ture

Ch

an

ge

/K

286

∆ T lt i

T tr i

T BA i

T F i

t i

∆

∆

∆

Steel tube

AA - wire

ACS - wire

Fiber

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Sample: AA/ACS 41/41 with Al-Tube

0 5 10 15 20 25 30

50

100

150

180

0

Te

mp

era

ture

Ch

an

ge

/K

∆ T lt i

T tr i

T BA i

T F i

∆

∆

∆

Time / s

t i

Aluminum tube

AA - wire

ACS - wire

Fiber

Conductivity

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Comparison Al-St-Tube

AA/ACS 41/41 High Current Test I2·t = 64 kA

2·s

0

50

100

150

200

250

300

350

AA Wires ACS Wires Tube Fiber

Ma

x. Te

mp

era

ture

/ K

Al-Tube

St-Tube

Conductivity

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Fiber Excess Length

Elongation

Contraction

Conventional Design:

Att

enuation c

hange

0

Tension

Cable

Fiber

Conventional design

CBT

Elo

ngation

Fiber Excess Length Design:

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-0,2

0,0

0,2

0,4

0,6

0,8

1,0

0 0,2 0,4 0,6 0,8 1

-0,2

0,0

0,2

0,4

0,6

0,8

1,0

Fiber strain / %

Attenuation / dB

Cable strain / %

Fib

er

str

ain

/ %

Att

enuation c

hange

(1550 n

m)

/ dB

No stretching of fibers

if cable is elongated

Enough safety

Included in the design

NSW Design Philosophy

Fiber Excess Length

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Central Buffer Tube Design

Highest protection of fibers

Low weight of cables means less additional loads on towers

Central buffer tube allows a wide range of fiber count within the same cable type

Long experience in manufacturing armored cables, including extended

knowledge in preforming of armoring wires

Extensive type testing demonstrates high performance safety

Minimized corrosion problems with “compatible” structure

Capability for better lightning protection in single layer designs

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Single layer design

- low cost producer depending on volume

- use of aluminum clad steel wires or a mixture

of aluminum alloy wires and aluminum clad

steel wires

Multi layer design

- low torsion due to pre-forming of wires

- load bearing elements (inner layer) are well

protected against lightning

- thermal advantages

- use aluminum wires, aluminum alloy wires and

aluminum clad steel wires

Central Buffer Tube Design

Introduction to NSW

4-Nov-13 / 19

NSW Famous Crossings

Special Engineering Difficulties

Installation

in China

Bosphorus

Crossing

Suez Channel

Crossing

Introduction to NSW

4-Nov-13 / 20

NSW Famous Crossings

Special Engineering Difficulties

• Customer: EEA, Cairo / Egypt

• Purpose of the Link:

• Connection of the 500 kV network of Egypt with

Sinai Peninsula and interconnection to Jordan

• Contractor: Siemens AG Erlangen / STFA Ankara

• Time Schedule

• Contract Award: March 1996

• Energizing: June 1998

Egypt

500 kV Suez Canal Crossing

Introduction to NSW

4-Nov-13 / 21

NSW Famous Crossings

Special Engineering Difficulties

Ratings

Max. Voltage: 525 kV

Max. Power (AC, therm., DIN): 2800 MVA/cct.

Towers: 220 m high Crossing Suspension Towers

equipped with elevator and aircraft warning lights

Number of Circuits: 2

Conductors per Phase: 3

Size of Conductor: AACSR/AW 290/64 mm²

Shield-wire: 2 OPGW AA/ACS 136/134

Insulators: Cap and Pin Type, Porcelain

Fittings: Double Suspension and Triple Tension String

Pile foundation: with 77 piles 0.75 m diameter

500 kV Suez Canal Crossing

Introduction to NSW

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NSW Famous Crossings

Special Engineering Difficulties

TYPE :

ASLH-DABBB1x24E9/125(AA/ACS 136/134)

Cable Design :

Central element :buffer tube, filled 3.80 mm 1st layer : 7 Al-clad steel wires (AW) 2.80 mm 2nd layer : 12 Al-clad steel wires (AW) 3.10 mm 3rd layer : 18 Al-Alloy wires (AY) 3.10 mm Mechanical data, measurements and weight : Diameter (approx.) : 21.8 mm

Weight of Cable (approx.) : 1305 kg / km

Rated Tensile Strength : 201 kN

Modulus of elasticity : 109 kN/mm2

Cross-section AW : 133.7 mm2

Cross-section AY : 135.9 mm2

Cross-section ratio : 1.0

Load-bearing cross-section : 269.5 mm2

Everyday stress (20 % RTS) : 149 N/mm2

Nominal transient current (TINITIAL = 20oC) : 15.4 kA (1s)

DC resistance (T=20oC) : 0.18 Ω / km

Coefficient of linear expansion : (10-6) 15.3 1/K

Deflecting radius / Bending radius (min.) : 440 / 330 mm

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NSW Famous Crossings

Special Engineering Difficulties

OPGW Project Suez Crossing

Introduction to NSW

4-Nov-13 / 24

NSW Famous Crossings

Special Engineering Difficulties

Turkey

• Customer: TEAS / Turkey

• Purpose of the Link:

• Interconnection of European and Asian Grid

with third Bosphorus Crossing using four

420 kV Circuits in first stage

• Contractor: Siemens AG Erlangen / STFA Ankara

• Contract Value:

• 27 Mio. US$

• Time Schedule

• Contract Award: Dec. 1997

• Energizing: Dec. 1998

380/735 kV Bosphorus Crossing

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4-Nov-13 / 25

NSW Famous Crossings

Special Engineering Difficulties

• Number of Circuits: 4

• Conductors per Phase: 1

• Size of Conductor : AACSR/AW 1802/226 mm²

• Shield-wire: 2 OPGW AW330 mm²

• Insulators: Cap and Pin Type, Glass

• Fittings: 4 x 20 psc. (Double V-Suspension String)

2 x 22 psc. (Double Suspension String)

2 x 20 psc. (Double Tension String)

Ratings

• Max. Voltage:420 kV (upgradable to 800 kV)

• Max. Power (AC, therm., DIN): 1600 MVA/cct

• Distance: 3.1 km (Crossing Section)

380/735 kV Bosphorus Crossing

Introduction to NSW

4-Nov-13 / 26

NSW Famous Crossings

Special Engineering Difficulties

Cable Design :

Central element : buffer tube, filled 6.00 mm

1st layer : 9 Al-clad steel wires (AW) 3.00 mm

2nd layer : 15 Al-clad steel wires (AW) 3.00 mm

3rd layer : 20 Al-clad steel wires (AW) 3.20 mm

Mechanical data, measurements and weight :

Diameter (approx.) : 24.4 mm

Weight of Cable (approx.) : 2350 kg / km

Rated Tensile Strength : 407 kN

Modulus of elasticity : 162 kN/mm2

Cross-section AW : 330.5 mm2

Load-bearing cross-section : 330.5 mm2

Everyday stress (20 % RTS) : 246 N/mm2

Nominal transient current (TINITIAL = 40oC) : 18.0 kA (0,5 s)

DC resistance (T=20oC) : 0.26 Ω / km

Coefficient of linear expansion (10-6) : 12.6 1/K

Deflecting radius / Bending radius (min.) : 490/370 mm

TYPE :

ASLH-DABBB1x22E9/125(ACS 300)

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NSW Famous Crossings

Special Engineering Difficulties

1884m 502m 728m

73m 70m 127m 88m

158m 153m

161m 64m 161m

64m

Europe Asia

Bosphorus

380/735 kV Bosphorus Crossing

Introduction to NSW

4-Nov-13 / 28

Thank you

for Your Attention!