Submarine Power Cables (eBook)

Design, Installation, Repair, Environmental Aspects

Thomas Worzyk (Autor)

eBook Download: PDF

2009 | 1. Auflage
XVII, 306 Seiten
Springer-Verlag
978-3-642-01270-9 (ISBN)

Infos

The demand for high-performance submarine power cables is increasing as more and more offshore wind parks are installed, and the national electric grids are interconnected. Submarine power cables are installed for the highest voltages and power to transport electric energy under the sea between islands, countries and even continents. The installation and operation of submarine power cables is much different from land cables. Still, in most textbooks on electrical power systems, information on submarine cables is scarce. This book is closing the gap. Different species of submarine power cables and their application are explained. Students and electric engineers learn on the electric and mechanic properties of submarine cables. Project developers and utility managers will gain useful information on the necessary marine activities such as pre-laying survey, cable lay vessels, guard boats etc., for the submarine cable installation and repair. Investors and decision makers will find an overview on environmental aspects of submarine power cables. A comprehensive reference list is given for those who want further reading.

Inhalt

Preface 5
Acknowledgments 7
Contents 8
About the Author 14
Abbreviations 15
1 Applications of Submarine Power Cables 16
1.1 Power Supply to Islands 16
1.2 Connection of Autonomous Grids 18
1.3 Offshore Wind Farms 18
1.4 Supply of Marine Platforms 19
1.5 Short-Haul Crossings 21
1.6 Other Applications of Submarine Power Cables 21
References 22
2 Submarine Power Cables and Their Design Elements 24
2.1 The Conductor 25
2.1.1 Solid Conductor 25
2.1.2 Conductors Stranded from Round Wires 26
2.1.3 Profiled Wire Conductors 27
2.1.4 Hollow Conductors for Oil-Filled Cables 28
2.1.5 Milliken Conductor 28
2.1.6 Conductor Resistance 30
2.1.7 Watertightness of Conductors 31
2.1.8 Superconducting Conductors 31
2.2 The Insulation System 32
2.2.1 Polyethylene 32
2.2.2 Cross-Linked Polyethylene 33
2.2.3 Conductor and Insulation Screen 34
2.2.4 The Influence of Ageing and Humidity on XLPE Insulation 35
2.2.5 Applications of XLPE Insulation 37
2.2.6 Extruded HVDC Cables 37
2.2.7 Other Extruded Insulation Systems 38
2.2.8 Paper-Insulated Oil-Filled Cables for a.c. or d.c. 38
2.2.9 Paper-Mass Insulation for HVDC 41
2.2.10 Gas-Filled Submarine Cables 43
2.2.11 Other Insulation Systems 44
2.3 The Water-Blocking Sheath 45
2.3.1 Lead Sheath 45
2.3.2 Aluminium Sheath 47
2.3.3 Copper Sheath 47
2.3.4 Polymeric Sheaths 48
2.4 Armoring 48
2.4.1 Corrosion Protection 52
2.5 Outer Serving 54
2.6 Three-Core Cables 55
2.6.1 Choice Between One Three-Core and Three Single-Core Cables 57
2.7 Two-Core Cables 58
2.8 Coaxial Cables 59
2.9 Optical Fibres Inside Submarine Power Cables 59
2.10 Five Generic Cable Types 62
References 63
3 Design 66
3.1 Thermal Design 66
3.1.1 Single-Core HVDC Cables 67
3.1.1.1 Single Buried Cable 71
3.1.1.2 A Pair of Buried Cables 71
3.1.2 a.c. Cables 74
3.1.2.1 Conductor Losses 74
3.1.2.2 Dielectric Losses 75
3.1.2.3 Screen Losses 76
3.1.2.4 a.c. Cable Ampacity 78
3.1.3 Other Factors for the Thermal Design 79
3.1.3.1 Transient Conditions 79
3.1.3.2 Temporary Overload 81
3.1.3.3 Cyclic or Variable Loads 84
3.1.3.4 Thermal Resistivity of the Seafloor 84
3.1.3.5 Ambient Temperature 86
3.1.3.6 Conditions Changing with Time 88
3.1.4 The 2 K Criterion 88
3.1.5 Economic Aspects of the Thermal Design 90
3.2 Design of Mechanical Properties 93
3.2.1 Tensional Forces During Laying 94
3.2.2 The Cigré Test Recommendation 96
3.2.3 Distribution of Mechanical Stress Between Conductor and Armoring 98
3.2.4 Other Forces and Impacts 100
3.2.5 Vortex Induced Vibrations 103
3.3 Electric Design 105
3.3.1 The Concept of Electric Strength 105
3.3.2 The Weibull Distribution 106
3.3.3 Dielectric Design of a.c. Cables 109
3.3.3.1 Overvoltages 110
3.3.3.2 Design Rules 111
3.3.4 Dielectric Design of d.c. Cables 112
3.3.5 Dielectric Design of Mass-Impregnated Cables 115
3.3.6 Impulse Stress 116
3.3.7 Availability and Reliability 117
References 118
4 Accessories 120
4.1 Submarine Cable Joints 120
4.1.1 Factory Joints 121
4.1.2 Offshore Installation Joints 123
4.1.2.1 Flexible Installation Joints 124
4.1.2.2 Rigid Joints 125
4.1.3 Miscellaneous Joint Designs 128
4.1.4 Beach Joints 129
4.2 Cable Terminations 130
4.2.1 On-Shore a.c. Cable Terminations 131
4.2.2 On-Shore d.c. Cable Terminations 131
4.2.3 Offshore Cable Terminations 133
4.3 Other Accessories 133
4.3.1 J-Tubes 133
4.3.2 Hang-Off 134
4.3.3 Bending Protection 135
4.3.4 Holding Devices 135
References 135
5 Manufacturing and Testing 137
5.1 Manufacturing 137
5.1.1 The Conductor 138
5.1.2 XLPE Cables 139
5.1.3 Paper-Insulated Cables 140
5.1.4 Sheathing 143
5.1.5 Lay-up 144
5.1.6 Armoring 145
5.1.7 Storage of Submarine Cables 148
5.2 Testing 150
5.2.1 Development Tests 150
5.2.2 Type Tests 151
5.2.2.1 Mechanical Tests 152
5.2.2.2 Load Cycle Test 155
5.2.2.3 Impulse Tests 157
5.2.3 Routine Tests 158
5.2.3.1 High-Voltage Routine Tests 158
5.2.4 Factory Acceptance Tests (FAT) 159
5.2.5 After-Installation Test 160
5.2.6 Non-electrical Tests 162
References 162
6 Marine Survey 164
6.1 Scope of the Marine Survey 165
6.2 Bathymetry 166
6.3 Sub-bottom Profiling 169
6.4 Visual Inspection 169
6.5 Soil Sampling 170
6.6 Soil and Water Temperatures 171
References 172
7 Installation and Protection of Submarine Power Cables 173
7.1 Installation 173
7.1.1 Cable Laying Vessels 174
7.1.2 Other Vessels 183
7.1.3 Loading and Logistics 185
7.1.4 Laying of Submarine Power Cables 186
7.1.4.1 Laying of Cable Around a Curve 189
7.1.5 Landing of Submarine Cables 189
7.1.6 Jointing of Submarine Power Cables 193
7.1.6.1 In-Line Joints 194
7.1.6.2 After-Installation Joints 195
7.1.7 Weather 198
7.1.7.1 Winds 198
7.1.7.2 Wave Properties 198
7.1.7.3 Vessel Movement 201
7.1.7.4 Other Impacts of Wind and Waves 204
7.1.8 Organisation 205
7.2 Protection of Submarine Power Cables 206
7.2.1 Selection of a Suitable Cable Route 207
7.2.2 Design of a Suitable Cable Armoring 208
7.2.3 External Protection 210
7.2.3.1 Trenching 211
7.2.3.2 Jetting Methods 212
7.2.3.3 Simultaneous or Post-Lay Burial? 213
7.2.3.4 Trenching Depth 214
7.2.3.5 Other Protection Methods 215
7.2.4 After-Installation Protection 217
7.3 Appendix: The Catenary Line 218
References 220
8 Damages and Repair 222
8.1 Damages 222
8.1.1 Causes of Damages 223
8.1.2 Statistic Distribution of Damages 224
8.1.3 Damage by Fishing Equipment 224
8.1.4 Damage by Anchors 226
8.1.5 Damage During the Installation 229
8.1.6 Other Damage 230
8.1.7 Spontaneous Damage 231
8.1.8 Failures of Joints 232
8.2 Repair 232
8.2.1 Spare Cable 233
8.2.2 Repair Vessel 234
8.2.3 Repair Crew 234
8.2.4 Repair Operation 235
8.3 Fault Location 236
8.3.1 TDR 236
8.3.2 Bridge Measurements 239
8.3.3 Fine Localisation 240
8.3.4 Optical Time Domain Reflectrometry 241
8.3.5 Other Methods 242
8.4 Repair Example 242
References 246
9 Operation and Maintenance: Reliability 248
9.1 Operation of Submarine Cables 248
9.1.1 Common Measures for All Kind of Submarine Power Cables 248
9.1.2 Instrumentation 249
9.1.2.1 DTS 250
9.1.2.2 CDVC 250
9.1.2.3 Partial Discharge Monitoring 250
9.1.3 Mass-Impregnated Cables and XLPE Cables 251
9.1.4 LPOF, SCOF and SCFF Cables 251
9.1.5 Cable Terminations 252
9.2 Reliability of Submarine Cables 252
9.2.1 The Cigré Studies 252
9.2.2 Failure Statistics for Large HVDC Cable Projects 253
9.2.3 Definition of Reliability Terms 255
9.2.4 Reliability of Some Specific Submarine Power Cables 255
9.2.4.1 Skagerrak HVDC Scheme 255
9.2.4.2 Windfarm Export Cable 256
9.2.4.3 Fox Islands 256
9.2.4.4 Long Island 256
9.2.4.5 Baltic Cable 257
References 258
10 Environmental Issues 259
10.1 Environmental Assessment 259
10.2 The Influence of Cable Losses 261
10.3 Environmental Aspects Related to Cable Design 262
10.3.1 Conductor Materials 262
10.3.2 Choice of Other Cable Materials 262
10.4 Environmental Aspects of Cable Installation 264
10.5 Environmental Impacts from the Operation of Submarine Power Cables 268
10.5.1 Thermal Impact 268
10.5.2 The 2 k Criterion 268
10.5.3 Electromagnetic Impact 271
10.5.4 Chemical Impact 276
10.6 Recycling of Submarine Power Cables 276
References 277
11 Anecdotes 279
11.1 The Floating Hospital S/S Castalia 280
11.2 HVDC Cable Between Lydd, UK and Boulogne, F 280
11.3 The Pilot 280
11.4 S-Lay and Coiling Direction 281
11.5 Edible Insulation 283
11.6 Flipper 283
11.7 Stamps 283
11.8 Unusual Cable Ships 284
11.9 Master Teredo 285
11.10 Krauts at War Searching for a Cable Break 286
11.11 Even More Damages 286
11.12 Loops 287
11.13 Cable Ship Reefs 287
11.14 Poetry 288
11.14.1 The Journey of Mrs. Florence Kimball Russel 289
References 290
12 Useful Tables 291
12.1 Dielectric Properties of Cable Insulation Material 291
12.2 Lead Alloys 291
12.3 Non-metric Conductor Size: kcmil 293
12.4 Non-metric Wire Diameter 293
12.5 The Galvanic Series of Metals and Alloys in Seawater 295
12.6 Classification of Submarine Soil in Different Countries 296
12.7 Non-metric Units 297
12.8 Tidal Terms 298
Reference 298
Index 299

Produkt-Details

• Erscheint lt. Verlag: 11.8.2009
• Reihe/Serie: Power Systems
• Zusatzinfo: XVII, 296 p. 178 illus.
• Verlagsort: Berlin
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Schlagworte: Interconnect • Manufacturing • Offshore • Offshore Engineering • Power Systems • Wind
• ISBN-10: 3-642-01270-1 / 3642012701
• ISBN-13: 978-3-642-01270-9 / 9783642012709