Accessories for HV and EHV Extruded Cables: Volume 2: Land and Submarine AC/DC Applications

Message from the President
Message from the Chairman of the Technical Council of CIGRE
Message from the Secretary General
Preface
Contents
About the Editor
Contributors
1 Accessories in Underground Cable Systems and in Transitions from Overhead to Underground
1.1 Introduction to the Chapter
1.1.1 Background
1.1.2 Content of the Chapter
1.1.3 General Process
1.2 System Requirements and Basic Concepts
1.2.1 Basics on Transmission Network
1.2.1.1 Functions of the Network
1.2.1.2 Types of Substations
1.2.1.3 Main Cable Circuit Configurations
1.2.1.3.1 Meshed Underground Network
1.2.1.3.2 Siphon
1.2.1.3.3 Substation Entrance
1.2.1.3.4 Power Generator Output
1.2.1.3.5 Power or Auxiliary Transformer Supply
1.2.1.4 The Overhead to Underground Transition
1.2.1.5 System Requirements
1.2.2 Parameters Determined by the Network
1.2.2.1 Main Equipment Parameters
1.2.2.2 Fault Clearance Times
1.3 Design and Construction Issues Relating to Underground Section
1.3.1 Introduction
1.3.1.1 Electrical Characteristics
1.3.1.2 Thermal Dimensioning
1.3.1.3 Economical Optimization of Conductor Area
1.3.1.3.1 Short Circuit Characteristics
1.3.1.4 Main Insulation Coordination
1.3.1.5 Choice of Grounding Technique
1.3.1.6 Protection and Reclosure
1.3.1.7 Magnetic Fields
1.3.2 Methodology
1.4 Laying Techniques and Installation Methods
1.4.1 Laying Techniques
1.4.1.1 Trenches (Direct Burial)
1.4.1.2 Ducts
1.4.1.3 Troughs
1.4.1.4 Tunnels
1.4.1.5 Microtunnels
1.4.1.6 Shafts
1.4.1.7 Bridges
1.4.1.8 Mechanical Laying
1.4.1.9 Horizontal Drilling
1.4.1.10 Pipe Jacking
1.4.1.11 Embedding
1.4.1.12 Use of Existing Structures
1.4.2 Installation Techniques
1.5 Accessories Installation
1.5.1 Quality Assurance Approval for Installation
1.5.2 Quality Plan
1.5.3 Training of Personnel
1.5.4 Assembly Instructions
1.5.5 Special Assembly Tools
1.5.6 Preparation of the Assembly Environment
1.5.6.1 Joint Assembly
1.5.6.2 Termination Assembly
1.6 Design and Construction Issues Relating to Overhead to Underground Transition
1.6.1 Options for Transition Overhead/Underground
1.6.2 Transition on Towers/Poles
1.6.3 Transition Compounds
1.7 Transition Compound
1.7.1 Planning
1.7.1.1 Extent of the Transition Compound
1.7.1.2 Connection Scheme
1.7.1.2.1 Operational Flexibility
1.7.1.2.2 Reliability and Availability
1.7.1.2.3 Service Continuity
1.7.1.2.4 Choice of Connection Arrangements
1.7.1.3 Fault Current Levels
1.7.1.4 Neutral Point Earthing
1.7.1.5 Protection in General
1.7.2 Site Selection
1.7.2.1 General
1.7.2.2 Environmental Aspects
1.7.2.2.1 Land
1.7.2.2.2 Water
1.7.2.2.3 Vegetation
1.7.2.2.4 Fauna
1.7.2.2.5 Population and Economy
1.7.2.2.6 Town Planning
1.7.2.2.7 Cultural Heritage
1.7.2.2.8 Infrastructures
1.7.2.2.9 Protected Natural Sites
1.7.2.2.10 Landscape
1.7.2.2.11 Access Route
1.7.2.2.12 Site Preparation
1.7.2.2.13 Other Environmental Considerations
1.7.2.3 Technical Aspects
1.7.2.3.1 Topography
1.7.2.3.2 Geological and Geotechnical Characteristics of Soil
1.7.2.3.3 Access
1.7.2.3.4 Line Corridors
1.7.2.3.5 Pollution
1.7.3 Overvoltage and Insulation Levels
1.7.4 Current Rating and Overcurrents
1.7.5 Electrical Clearances
1.7.6 Direct Lightning Stroke Shielding
1.7.7 Earthing for Personnel Safety
1.7.8 Corona and Radio Interference
1.7.9 Acoustic Noise
1.7.10 Water Contamination
1.7.11 Mechanical Forces
1.7.11.1 Weight
1.7.11.2 Wind Loading
1.7.11.3 Earthquake
1.7.11.4 Short-Circuit
1.7.11.5 Combinations of Forces
1.7.12 Civil Design
1.7.12.1 Supporting Structures
1.7.12.2 Foundations
1.7.12.3 Site Facilities
1.7.12.4 Fencing
1.7.12.5 Buildings
1.7.13 Fire Protection
1.7.14 Transition Compound Security
1.7.15 Energy Efficiency in Transition Compounds
1.8 Commissioning
1.9 Operation
References
2 Safe Work Under Induced Voltages or Currents
2.1 Introduction
2.1.1 Definition of Induced Voltages
2.1.2 Inductive Coupling
2.1.3 Capacitive Coupling
2.1.4 Conductive Coupling (Earth Potential Rise, or EPR)
2.1.5 Trapped Charge and Dielectric Polarization
2.1.6 Limits for Induced Voltages
2.1.6.1 Acceptable Currents Passing Through the Human Body
2.1.6.2 Impedance of the Body
2.1.6.2.1 Source Impedance (ZS)
2.1.6.2.2 Body Impedance (Zb)
2.1.6.2.3 Additional Impedances (Ra and Rb)
2.1.6.2.4 Summary of Impedance Effects
2.1.6.3 Touch Voltage Limits
2.1.6.3.1 Long-Term Influences
2.1.6.3.2 Short-Term Influence
2.1.6.3.3 Very Short-Term Influence
2.2 Principles of Safe Work
2.2.1 Risk Analysis
2.2.2 Earthed Working
2.2.2.1 Earthed Working Without Currents
2.2.2.2 Earthed Working with Currents
2.2.2.3 Earthing Equipment
2.2.3 Insulated Working
2.2.4 Protection Against Re-energization During Work
2.3 Work Procedures
2.3.1 Measuring Earthing Resistances/Earth Electrode Impedances
2.3.2 Cable Pulling
2.3.2.1 Cable Pulling for Cables in Open Trenches, Ducts, and HDD
2.3.2.2 Cable Installation When Ploughing Cables
2.3.3 Cable Jointing
2.3.3.1 Cable Ends Preparation
2.3.3.2 Joint Components Parking (If Applicable)
2.3.3.3 Conductor Connection
2.3.3.4 Joint Completion
2.3.4 Terminations
2.3.4.1 AIS Terminations
2.3.4.2 GIS Terminations
2.3.4.3 Transformer Terminations
2.3.5 Work on Link Boxes
2.3.6 Cable Testing
2.3.7 Removing Cables
2.3.8 Working Procedure in Special Conditions
2.3.8.1 Installation and Repair in Tunnels
2.3.8.1.1 Cable Pulling in Tunnels
2.3.8.1.2 Jointing in Tunnels
2.3.8.2 Installation and Repair Offshore
2.4 Method of Calculation
2.4.1 Inductive Coupling
2.4.2 Capacitive Coupling
2.4.3 Conductive Coupling: Rise of Earth Potential
2.5 Conclusions and Recommendations
2.5 Appendixes
Appendix A: Recommendations: Touch Voltage Limits
A1: Recommendations Toward IEC on Setting Standard Touch Voltage for Cable Systems
A2: Calculations of Touch Voltage Based on Body Current
Appendix B: Calculation of Series and Mutual Impedances
Appendix C: Cable Testing
C1: Primary Voltage Testing
C2: Oversheath Voltage Testing
C3: Testing and Configuring Special Bonding
C4: Measuring Earth Electrode Impedances
C5: Special Situations
C6: Searching for a Fault
Appendix D: Examples
References
3 Long AC Extruded Submarine Cables: Recommendations for Testing Cables and Accessories
3.1 Introduction
3.1.1 Background
3.1.2 Terms of Reference
3.1.3 Scope
3.1.4 Experience of Extruded AC Submarine Cables Above 170 kV
3.2 Definitions
3.3 Current Technologies for Submarine Cable Designs
3.3.1 General Aspects on Water Tightness
3.3.2 Conductors
3.3.3 Insulation System
3.3.4 Metal Screen/Sheath
3.3.5 Armor
3.3.6 Outer Protection
3.4 Current Technologies for Submarine Joint Designs
3.4.1 Factory Joints
3.4.1.1 General Considerations for Factory Joints
3.4.1.2 Typical Procedure for Factory Jointing
3.4.2 Repair Joints
3.4.2.1 General Considerations for Repair Joints
3.4.2.2 Typical Procedure for Repair Jointing
3.4.2.2.1 Type A1: Fully Flexible Joint
3.4.2.2.2 Type A2: Flexible Joint with Some Mechanical Restrictions
3.4.2.2.3 Type B: Rigid Joint
3.4.3 Sea/Land Transition Joint
3.5 General Aspects on Submarine Cable Testing
3.5.1 Summary of Tests
3.5.2 Test Conditions
3.5.2.1 Ambient Temperature
3.5.2.2 Frequency and Wave Form of AC Test Voltages
3.5.2.3 Wave Form of Impulse Test Voltage
3.5.2.4 Relationship of Test Voltages and Rated Voltages
3.5.3 Characteristics of Cables
3.5.4 Development Tests
3.6 Routine Test
3.6.1 General
3.6.2 Available High Voltage Test Methods
3.6.3 Tests on Manufactured Lengths
3.6.3.1 Partial Discharge Test
3.6.3.2 High Voltage Test
3.6.4 Tests on Factory Joints
3.6.5 Tests on Complete Delivery Length
3.6.5.1 High Voltage Test
3.6.5.2 Partial Discharge Test
3.6.6 Tests on Repair Joint
3.6.7 Tests on Terminations
3.7 Sample Test
3.7.1 Sample Tests on Cables
3.7.1.1 General
3.7.1.2 Frequency of Tests
3.7.1.3 Repetition of Tests
3.7.1.4 Conductor Examination
3.7.1.5 Measurement of Electrical Resistance of Conductor and, on Completed Core, of Metal Screen/Sheath
3.7.1.6 Measurement of Thickness of Insulation and Cable Oversheath
3.7.1.7 Measurement of Thickness of Metal Sheath
3.7.1.8 Measurement of Thickness of Inner Nonmetallic Sheath
3.7.1.9 Measurement of Diameters of Conductor, Core, and Metal Sheath
3.7.1.10 Hot Set Test for Extruded Insulation
3.7.1.11 Measurement of Capacitance
3.7.1.12 Measurement of Density of HDPE Insulation
3.7.1.13 Partial Discharge Test
3.7.1.14 Lightning Impulse Voltage Test
3.7.1.15 Volume Resistivity of Conductor Screen, Insulation Screen, and Semiconductive Polymeric Sheath
3.7.1.16 Examination of Completed Cable
3.7.2 Sample Tests on Factory Joints
3.7.2.1 General
3.7.2.2 PD Measurement and AC Voltage Test
3.7.2.3 Lightning Impulse Voltage Test
3.7.2.4 Hot Set Test for Extruded Insulation
3.7.2.5 Tensile Test
3.7.2.6 Pass Criteria
3.7.3 Sample Tests on Repair Joints and Terminations
3.8 Type Test on Cable System
3.8.1 General
3.8.2 Range of Type Approval
3.8.3 Summary of Tests
3.8.4 Preparation of Tests
3.8.5 Check on Insulation Thickness of Cable for Electrical Type Tests
3.8.6 Mechanical Tests on Complete Cable System
3.8.6.1 Cables and Factory Joints
3.8.6.2 Repair Joints
3.8.7 Longitudinal/Radial Water Penetration (LWP, RWP) Test
3.8.7.1 Background to the LWP, RWP Test
3.8.7.2 Conductor Water Penetration Test
3.8.7.3 Metal Sheath Water Penetration Test
3.8.7.4 Radial Water Penetration Test for Joints
3.8.8 Electrical Tests on Complete Cable System
3.8.9 Non-Electrical Tests on Cable Components and Complete Cable
3.8.9.1 Check of Cable Construction
3.8.9.2 Tests for Determining the Mechanical Properties of Insulation Before and After Aging
3.8.9.3 Tests for Determining the Mechanical Properties of Oversheaths Before and After Aging
3.8.9.4 Ageing Tests on Pieces of Complete Cable to Check Compatibility of Materials
3.8.9.5 Loss of Mass Test on PVC Oversheaths of Type ST2
3.8.9.6 Pressure Test at High Temperature on Oversheaths
3.8.9.7 Test on PVC Oversheaths (ST1 and ST2) at Low Temperature
3.8.9.8 Heat Shock Test for PVC Oversheaths (ST1 and ST2)
3.8.9.9 Ozone Resistance Test for EPR Insulation
3.8.9.10 Hot Set Test for EPR, HEPR, and XLPE Insulations
3.8.9.11 Measurement of Density of HDPE Insulation
3.8.9.12 Measurement of Carbon Black Content of Black PE Oversheaths
3.8.9.13 Test Under Fire Conditions
3.8.9.14 Determination of Hardness of HEPR Insulation
3.8.9.15 Determination of the Elastic Modulus of HEPR Insulation
3.9 Prequalification Test
3.9.1 Introduction
3.9.2 Range of Prequalification Test Approval
3.9.3 Prequalification Test on Complete Cable System
3.9.3.1 Check on Insulation Thickness and Test Voltage Values for Electrical Prequalification Test
3.9.3.2 Test Arrangement
3.9.3.3 Heating Cycle Voltage Test
3.9.3.4 Lightning Impulse Voltage Test on Cable Samples
3.9.3.5 Examination
3.10 Extension of Qualification Test
3.11 Electrical Tests After Installation
3.11.1 High Voltage Test
3.11.2 Time Domain Reflectometry (TDR)
3.11 Appendices
Appendix A: Routine Test
Appendix B: Sample Test
Appendix C: Type Test
Appendix D: Prequalification Test
Appendix E: Extension of Qualification Test
Appendix F: After Installation Test
Appendix G: Abbreviations
References
4 Basics on Construction and Installation Methods
4.1 Introduction
4.2 Description of the Cable System
4.2.1 Main Cable Systems Configurations
4.2.2 Cable
4.2.3 Accessories
4.2.3.1 General
4.2.3.2 Accessory Types
4.2.3.2.1 Types of Joints
4.2.3.2.2 Types of Terminations
4.2.3.3 Compatibility of the Accessory with the Cable
4.2.3.3.1 Number of Cable Cores
4.2.3.3.2 Cable Constructional Details
4.2.3.3.3 Conductor Area and Diameter
4.2.3.3.4 Operating Temperature of the Cable Conductor and Sheath
4.2.3.3.5 Chemical Compatibility with the Extruded Cable
4.2.3.3.6 Cable Electrical Design Stresses to be Withstood by the Accessory
4.2.3.3.7 Mechanical Forces and Movements Generated by the Cable on the Accessory
4.2.3.3.8 Short Circuit Forces
4.2.3.4 Compatibility of the Accessory Performance with that of the Cable System
4.2.3.4.1 Circuit Performance Parameters
4.2.3.4.2 Circuit Life Required
4.2.3.4.3 Metallic Screen Bonding Requirements
4.2.3.4.4 Earth Fault Requirements
4.2.3.5 Compatibility of the Accessory with the Cable System Design and Operating Conditions
4.2.3.5.1 Type of Cable Installation Design
4.2.3.5.2 Standard Dimensions for Cable Termination
4.2.3.5.2.1 Outdoor and Indoor Termination
4.2.3.5.2.2 GIS and Transformer Termination
4.2.3.5.3 Types of Accessory Installations
4.2.3.5.4 Jointing Limitations in Restricted Installation Locations
4.2.3.5.5 Mechanical Forces Applied to the Accessory
4.2.3.5.6 Climatic Conditions
4.2.3.5.7 Type of Accessory Outer Protection Required
4.2.3.5.8 Situations Requiring Special Accessory Protection
4.2.3.5.9 Quality Assurance Scheme for Accessory Installation
4.2.3.5.9.1 Quality Assurance Approval for Installation
4.2.3.5.9.2 Quality Plan
4.2.3.5.10 Training of Personnel
4.2.3.5.11 Assembly Instructions
4.2.3.5.12 Special Assembly Tools
4.2.3.5.13 Preparation of the Assembly Environment
4.2.3.6 Compatibility of the Accessory with Specified After Laying Tests
4.2.3.7 Maintenance Requirements of the Accessory
4.2.3.7.1 Monitoring of Fluid Insulation
4.2.3.7.2 Voltage Withstand Tests on the Over Sheath and Joint Protection
4.2.3.7.3 Shelf Life of Accessories for Emergency Spares
4.2.3.7.4 Availability of Accessory Kits for Emergency Spares
4.2.3.8 Economics of Accessory Selection
4.2.3.8.1 Cost of the Accessory Complete with All Components
4.2.3.8.2 Cost of Guarantee and Insurance
4.2.3.8.3 Cost of Assembly Time
4.2.3.8.4 Cost of Preparing the Installation Environment for the Accessory
4.2.3.8.5 Cost of Safe Working Conditions
4.2.3.8.6 Cost of Special Jointing Tools
4.2.3.8.7 Cost of Training
4.2.3.8.8 Comparative Cost of Cable and Accessories
4.2.3.8.9 Cost of Verification of Accessory Performance
4.3 Construction Techniques
4.3.1 Definition of the Main Technical Terms
4.3.2 Description of Traditional Techniques
4.3.2.1 Ducts
4.3.2.1.1 Description of the Technique
4.3.2.1.2 Limits of the Technique
4.3.2.1.2.1 Civil Work
4.3.2.1.2.2 Drying of the Soil
4.3.2.1.2.3 Water Drainage
4.3.2.1.2.4 Temperature of the Soil/Environment
4.3.2.1.2.5 Hardness of the Soil
4.3.2.1.2.6 Stability of the Soil
4.3.2.1.2.7 Thermal Resistivity of the Soil
4.3.2.1.2.8 Seismicity
4.3.2.1.2.9 Frost
4.3.2.1.2.10 Archaeology
4.3.2.1.2.11 Presence of Termites
4.3.2.1.2.12 Laying in National Park
4.3.2.1.2.13 Duration of the Work
4.3.2.1.2.14 Maintenance and Repairing Process
4.3.2.1.2.15 Cable Removal After Operation
4.3.2.1.2.16 Adaptation of the Technique to the Cable System Design
4.3.2.2 Direct Burial
4.3.2.2.1 Description of the Technique
4.3.2.2.2 Limits of the Technique
4.3.2.2.2.1 Civil Work
4.3.2.2.2.2 Drying of the Soil
4.3.2.2.2.3 Water Drainage
4.3.2.2.2.4 Temperature of the Soil/Environment
4.3.2.2.2.5 Hardness of the Soil
4.3.2.2.2.6 Stability of the Soil
4.3.2.2.2.7 Thermal Resistivity of the Soil
4.3.2.2.2.8 Seismicity
4.3.2.2.2.9 Frost
4.3.2.2.2.10 Archaeology
4.3.2.2.2.11 Presence of Termites
4.3.2.2.2.12 Laying in National Park
4.3.2.2.2.13 Duration of the Work
4.3.2.2.2.14 Maintenance and Repairing Process
4.3.2.2.2.15 Cable Removal After Operation
4.3.2.2.2.16 Adaptation of the Technique to the Cable System Design
4.3.2.3 Tunnels
4.3.2.3.1 Description of the Technique
4.3.2.3.2 Limits of the Technique
4.3.2.3.2.1 Civil Work
4.3.2.3.2.2 Drying of the Soil
4.3.2.3.2.3 Water Drainage
4.3.2.3.2.4 Temperature of the Soil / Environment
4.3.2.3.2.5 Hardness of the Soil
4.3.2.3.2.6 Stability of the Soil
4.3.2.3.2.7 Thermal Resistivity of the Soil
4.3.2.3.2.8 Seismicity
4.3.2.3.2.9 Frost
4.3.2.3.2.10 Archaeology (Prehistoric Sites)
4.3.2.3.2.11 Presence of Termites
4.3.2.3.2.12 Laying in National Park
4.3.2.3.2.13 Duration of the Work
4.3.2.3.2.14 Maintenance and Repairing Process
4.3.2.3.2.15 Cable Removal After Operation
4.3.2.3.3 Adaptation of the Technique to the Cable System Design
4.3.2.3.3.1 Planning
4.3.2.3.3.2 Basic Design
4.3.2.3.3.3 Snaking Design
4.3.2.4 Troughs
4.3.2.4.1 Description of the Technique
4.3.2.4.2 Existing Installation Techniques
4.3.2.4.3 Installation Methods
4.3.2.4.4 Limits of the Technique for Buried Troughs
4.3.2.4.4.1 Civil Work
4.3.2.4.4.2 Drying of the Soil
4.3.2.4.4.3 Hardness of the Soil
4.3.2.4.4.4 Stability of the Soil
4.3.2.4.4.5 Thermal Resistivity of the Soil
4.3.2.4.5 Limits of the Technique for Surface Troughs
4.3.3 Description of Innovative Techniques
4.3.3.1 Bridges
4.3.3.1.1 Description of the Technique
4.3.3.1.2 Limits of the Technique
4.3.3.1.2.1 Civil Work
4.3.3.1.2.2 Temperature of the Soil/Environment
4.3.3.1.2.3 Seismicity
4.3.3.1.2.4 Frost
4.3.3.1.2.5 Presence of Termites
4.3.3.1.2.6 Maintenance and Repairing Process
4.3.3.1.2.7 Cable Removal After Operation
4.3.3.2 Shafts
4.3.3.2.1 Description of the Technique
4.3.3.2.2 Limits of the Technique
4.3.3.2.2.1 Civil Work
4.3.3.2.2.2 Water Drainage
4.3.3.2.2.3 Temperature of the Soil/Environment
4.3.3.2.2.4 Thermal Resistivity of the Soil
4.3.3.2.2.5 Seismicity
4.3.3.2.2.6 Duration of the Work
4.3.3.2.2.7 Maintenance and Repairing Process
4.3.3.2.2.8 Cable Removal After Operation
4.3.3.3 Horizontal Drilling
4.3.3.3.1 Description of the Technique
4.3.3.3.1.1 Introduction
4.3.3.3.1.2 Principle
4.3.3.3.2 Process
4.3.3.3.2.1 Pilot Drilling
4.3.3.3.2.2 Back Reaming
4.3.3.3.3 Cable Rating and Bonding
4.3.3.3.3.1 Depth of the Installation
4.3.3.3.3.2 Separation between phases
4.3.3.3.3.3 Bonding
4.3.3.3.3.4 Pipe material and losses
4.3.3.3.3.5 Conduit material and losses
4.3.3.3.3.6 Pipe/conduit filling.
4.3.3.3.3.7 Horizontal - Water - Closed at both ends
4.3.3.3.3.8 Distributed Temperature Systems
4.3.3.3.3.9 Drying of the soil.
4.3.3.3.3.10 Temperature of the soil/Environment
4.3.3.3.4 Mechanical and Cable Installation
4.3.3.3.5 Maintenance and Removal/Repair
4.3.3.3.6 Advantages and Limits of the HDD Technique
4.3.3.3.6.1 Advantages
4.3.3.3.6.2 Limits
4.3.3.4 Pipe Jacking/Microtunnelling
4.3.3.4.1 Description of the Technique
4.3.3.4.1.1 Construction Process
4.3.3.4.1.2 Jacking Lengths
4.3.3.4.1.3 Intermediate Jacking Stations
4.3.3.4.1.4 Lubrication
4.3.3.4.1.5 Jacking Loads
4.3.3.4.1.6 Jacking Tolerances
4.3.3.4.1.7 Spoil Removal
4.3.3.4.2 Cable Rating and Bonding
4.3.3.4.3 Mechanical and Cable Installation
4.3.3.4.3.1 Use of Cementitious Grouts to Fill Space Between Cable and Pipe/Conduit
4.3.3.4.3.2 Shafts Effects
4.3.3.4.4 Maintenance and Removal/Repair of Asset
4.3.3.4.4.1 Maintenance and Repairing Process
4.3.3.4.4.2 Repair of Cables Installed Without Conduits
4.3.3.4.4.3 Repair of Cables Installed with Conduits
4.3.3.4.4.4 Cable Removal After Operation
4.3.3.4.5 Advantages and Limits of Pipe Jacking/Microtunnelling
4.3.3.4.5.1 Advantages
4.3.3.4.5.2 Limits of the Technique
4.3.3.5 Mechanical Laying (Fig. 4.31)
4.3.3.5.1 Description of the Technique
4.3.3.5.1.1 Laying Principle (HV Cable Systems)
4.3.3.5.2 Limits of the Technique
4.3.3.5.2.1 Civil Work
4.3.3.5.2.2 Temperature of the Soil/Environment
4.3.3.5.2.3 Hardness of the Soil
4.3.3.5.2.4 Seismicity
4.3.3.5.2.5 Archaeology
4.3.3.5.2.6 Presence of Termites
4.3.3.5.2.7 Laying in National Park
4.3.3.5.2.8 Duration of the Work
4.3.3.6 Embedding
4.3.3.6.1 Description of the Technique
4.3.3.6.2 Limits of the Technique
4.3.3.6.2.1 Civil Work
4.3.3.6.2.2 Method of Operation
4.3.3.6.2.3 Method of Excavation
4.3.3.6.2.4 Propulsion
4.3.3.6.2.5 Operators
4.3.3.6.2.6 Hardness of the Soil
4.3.3.6.2.7 Maintenance and Repairing Process
4.3.3.6.2.8 Environment
4.3.3.7 Use of Existing Structures
4.3.3.7.1 Description of the Technique
4.3.3.7.2 Limits of the Technique
4.3.3.7.2.1 Civil Work
4.3.3.7.2.2 Drying of the Soil
4.3.3.7.2.3 Duration of the Work
4.3.3.7.2.4 Cable Removal After Operation
4.3.3.7.3 Adaptation of the Technique to the Cable System Design
4.4 Cable Installation Design and Laying Techniques
4.4.1 Cable Installation Design
4.4.1.1 Installation Design in Air
4.4.1.1.1 Rigid Systems
4.4.1.1.1.1 Calculation of Cable Thrust
4.4.1.1.1.2 Spacing and Cleating
4.4.1.1.2 Flexible Systems (Western Approach)
4.4.1.1.2.1 Cables Cleated with Movement in a Vertical Plane
4.4.1.1.2.2 Flexible System with Cable Movement in a Horizontal Plan
4.4.1.1.2.3 Short Circuit Forces in Flexible Type Cable Installation
4.4.1.1.3 Flexible Systems (Japanese Approach)
4.4.1.1.3.1 Horizontal Snaking Installation (Fig. 4.41)
4.4.1.1.3.2 Vertical Snaking Installation (Fig. 4.42)
4.4.1.1.3.3 Vertical Installation Design
4.4.1.1.4 Cable in Ducts
4.4.1.2 Installation Design for Buried Cables
4.4.1.2.1 Backfill
4.4.1.2.1.1 Sand
4.4.1.2.1.2 Special Backfill
4.4.1.2.2 Cooling Systems
4.4.1.3 Transition Between Different Installation Types
4.4.1.3.1 Transition Between Ducts and Manholes (Open Air)
4.4.1.3.2 Transition Between Flexible and Rigid Systems (Open Air)
4.4.1.3.3 Transition Between Flexible and Rigid Systems (Buried)
4.4.2 Cable Laying and Installation Techniques
4.4.2.1 Cable Pulling Calculations
4.4.2.1.1 Clearance in Ducts
4.4.2.1.2 Pulling Tension
4.4.2.1.3 Side Wall Pressure
4.4.2.2 Installation Methods
4.4.2.2.1 Introduction
4.4.2.2.2 Nose Pulling
4.4.2.2.3 Synchronized Power Drive Rollers
4.4.2.2.4 Caterpillar or Hauling Machine
4.4.2.2.5 Bond Pulling
4.4.2.2.6 Mechanical Laying
4.4.2.2.7 Other Installation Methods in Tunnel
4.4.2.3 Installation Process
4.4.2.3.1 Transportation of Cable to Site
4.4.2.3.2 Cable Bending Radius
4.4.2.3.3 Cable Temperature
4.4.2.3.4 Pulling Length
4.4.2.3.5 Route Profile
4.4.2.3.6 Obstacles
4.4.2.3.7 Setting Up
4.4.2.3.8 Installation of Cable
4.4.2.3.9 Final Installation Stages
4.4.2.3.10 Site Quality Assurance
4.4.2.3.11 After Laying Tests
4.4.2.4 Adaptation of the Cable System Design to the Technique/Environment
4.4.2.4.1 Adaptation of the Cable System Design to the Technique
4.4.2.4.1.1 Ducts
4.4.2.4.1.2 Direct Burial
4.4.2.4.1.3 Tunnels
4.4.2.4.1.4 Troughs
4.4.2.4.1.5 Bridges
4.4.2.4.1.6 Shafts
4.4.2.4.1.7 Horizontal Drilling
4.4.2.4.1.8 Pipe Jacking
4.4.2.4.1.9 Microtunnels
4.4.2.4.1.10 Mechanical Laying
4.4.2.4.1.11 Embedding
4.4.2.4.1.12 Use of Existing Structures
4.4.2.4.2 Adaptation of the Cable System Design to the Environment
4.4.2.4.2.1 Drying of Soil
4.4.2.4.2.2 Water Drainage
4.4.2.4.2.3 Temperature of the Soil/Environment
4.4.2.4.2.4 Hardness of the Soil
4.4.2.4.2.5 Stability of the Soil
4.4.2.4.2.6 Thermal Resistivity of the Soil
4.4.2.4.2.7 Seismicity
4.4.2.4.2.8 Frost
4.4.2.4.2.9 Archaeology
4.4.2.4.2.10 Presence of Termites
4.4.2.4.2.11 Laying in National Park
4.4.2.4.2.12 Duration of the Work
4.4.2.4.2.13 Maintenance and Repairing Process
4.4.2.4.2.14 Cable Removal After Operation
4.5 External Aspects
4.5.1 Location (Urban vs. Rural)
4.5.2 Right of Way
4.5.3 Magnetic Fields
4.5.3.1 Flat Arrangement
4.5.3.2 Trefoil Arrangement
4.5.3.3 Vertical Arrangement
4.5.3.4 Comparison Between Overhead Lines and Buried Links
4.5.3.5 Conclusion
4.5.4 Existing Services
4.5.5 Legal Aspects
4.5.6 Safety Aspects
4.5.6.1 Protection of the Link from External Damage
4.5.6.2 Protection of the Environment from a System Fault
4.5.6.3 Protection of the Workers
4.5.6.4 Protection of the Public
4.5.6.5 Safety of the Different Laying Techniques
4.5.7 Environment
4.6 Design of A Link
4.6.1 Methodology
4.6.2 Study cases
4.7 Glossary
5 Recommendations for Mechanical Testing of Submarine Cables (and Their Accessories)
5.1 Introduction
5.1.1 Background
5.1.2 Terms of Reference
5.1.3 Scope
5.2 Definitions
5.3 Mechanical Handling of Submarine Cables
5.3.1 Risk of Mechanical Damage During a Cable´s Life Cycle
5.3.2 Submarine Cable Loading and Transportation
5.3.3 Submarine Cable Laying
5.3.3.1 Typical Installation Sequence with Shore Landing
5.3.3.2 Installation at Offshore Platforms
5.3.3.2.1 Pull-In Head
5.3.3.2.2 Hang-off
5.3.3.3 Vessel and Machines Positioning
5.3.3.4 Remotely Operated Vehicle (ROV)
5.3.3.5 Laying of Bundled Cables
5.3.3.6 Fatigue During Installation and Jointing
5.3.4 Submarine Cable Protection Techniques
5.3.4.1 Route Survey
5.3.4.2 Choosing of Cable Route and Protection Techniques
5.3.4.3 Ploughing
5.3.4.4 Water Jetting
5.3.4.5 Vertical Injector (Jetting Assisted Plough)
5.3.4.6 Trenching
5.3.4.7 Pipes at Landings
5.3.4.8 Excavation
5.3.4.9 Pre-Sweeping
5.3.4.10 Rock Placement
5.3.4.11 Mattress Coverings
5.3.4.12 Split-Pipe Articulated Cable Protectors
5.3.4.13 Other Complementary Protection Techniques
5.3.4.14 Protection of Cables at Crossings
5.3.5 Submarine Cable Operation and Maintenance
5.3.5.1 Possible Hazards for Cables in Operation
5.3.5.2 Vortex-Induced Vibrations, Strumming
5.3.5.3 Thermal Fatigue
5.3.5.4 Repeated Protection
5.3.5.5 Abrasion
5.3.6 Submarine Cable Repair
5.3.7 Dynamic Submarine Cables
5.3.7.1 Extreme Load Effect and Fatigue Analysis
5.3.7.2 Accessories
5.3.7.2.1 Bend Stiffener
5.3.7.2.2 Buoyancy Modules
5.4 General aspect of mechanical testing
5.4.1 Summary of Type Tests
5.4.1.1 Static Cables
5.4.1.2 Dynamic Cables
5.4.2 Test Conditions
5.4.3 Characteristics of Cable Design/Installation Methods
5.4.4 Test Tension
5.4.4.1 Water Depth 0-500 m
5.4.4.2 Water Depth >500 m or When Dynamic Vessel Characteristics Are Known
5.4.4.2.1 Calculation of Maximum Installation Tensile Force
5.4.4.2.2 Safety Factors to Establish the Test Tension
5.5 Type Tests
5.5.1 Coiling Test
5.5.1.1 Purpose/Applicability
5.5.1.2 Preparations/Conditions
5.5.1.3 Test
5.5.1.4 Requirements/Discussion
5.5.2 Tensile Bending Test
5.5.2.1 Purpose/Applicability
5.5.2.2 Preparations/Conditions
5.5.2.3 Test
5.5.2.4 Discussion/Requirements
5.5.3 Pressure and Water Penetration Tests on Paper Lapped Cable Types
5.5.3.1 External Water Pressure Tests: Mass-Impregnated Cables
5.5.3.1.1 Purpose/Applicability
5.5.3.1.2 Preparations/Conditions
5.5.3.1.3 Test
5.5.3.1.4 Discussion/Requirements
5.5.3.2 External Water Pressure Tests: Oil-Filled Cables
5.5.3.2.1 Purpose/Applicability
5.5.3.2.2 Preparations/Conditions
5.5.3.2.3 Test
5.5.3.2.4 Discussion/Requirements
5.5.3.3 Internal Pressure Withstand Test: Oil-filled Cables
5.5.3.3.1 Purpose/Applicability
5.5.3.3.2 Preparations/Conditions
5.5.3.3.3 Test
5.5.3.3.4 Discussion/Requirements
5.5.4 Pressure and Water Penetration Tests on Extruded Cable Types
5.5.4.1 Radial Water Penetration Test: Rigid Joint
5.5.4.1.1 Purpose/Applicability
5.5.4.1.2 Preparations/Conditions
5.5.4.1.3 Test
5.5.4.1.4 Discussion/Requirements
5.5.4.2 Radial Water Penetration Test: Factory Joint and Cable
5.5.4.2.1 Purpose/Applicability
5.5.4.2.2 Preparations/Conditions
5.5.4.2.3 Test
5.5.4.2.4 Discussion/Requirements
5.5.4.3 Conductor Water Penetration Test
5.5.4.3.1 Purpose/Applicability
5.5.4.3.2 Preparations/Conditions
5.5.4.3.3 Test
5.5.4.3.4 Discussion/Requirements
5.5.4.4 Metal Sheath Water Penetration Test
5.5.4.4.1 Purpose/Applicability
5.5.4.4.2 Preparations/Conditions
5.5.4.4.3 Test
5.5.4.4.4 Discussion/Requirements
5.5.5 Tensile Test
5.5.5.1 Purpose/Applicability
5.5.5.2 Preparations/Conditions
5.5.5.3 Test
5.5.5.4 Discussion/Requirements
5.5.6 Full Scale Fatigue Test: Dynamic Cables
5.5.6.1 Purpose/Applicability
5.5.6.2 Preparations/Conditions
5.5.6.3 Test
5.5.6.4 Discussion/Requirements
5.6 Project Specific Tests and Special Tests
5.6.1 Introduction
5.6.2 Bending Test Without Tension
5.6.2.1 Purpose/Applicability
5.6.2.2 Preparations/Conditions
5.6.2.3 Test
5.6.2.4 Discussion/Requirements
5.6.3 Crush Test
5.6.3.1 Purpose/Applicability
5.6.3.2 Preparations/Conditions
5.6.3.3 Test
5.6.3.4 Discussion/Requirements
5.6.4 Crush Test for Long-Term Stacking
5.6.4.1 Purpose/Applicability
5.6.4.2 Preparations/Conditions
5.6.4.3 Test
5.6.4.4 Discussion/Requirements
5.6.5 Sidewall Force Test
5.6.5.1 Purpose/Applicability
5.6.5.2 Preparations/Conditions
5.6.5.3 Test
5.6.5.4 Discussion/Requirements
5.6.6 Impact Test
5.6.6.1 Purpose/Applicability
5.6.6.2 Preparations/Conditions
5.6.6.3 Test
5.6.6.4 Discussion/Requirements
5.6.7 Pulling Stocking Test
5.6.7.1 Purpose/Applicability
5.6.7.2 Preparations/Conditions
5.6.7.3 Test
5.6.7.4 Discussion/Requirements
5.6.8 Handling Test for Rigid Joint
5.6.8.1 Purpose/Applicability
5.6.8.2 Preparations/Conditions
5.6.8.3 Test
5.6.8.4 Discussion/Requirements
5.6.9 Sea Trial
5.6.9.1 Purpose/Applicability
5.6.9.2 Preparations/Conditions
5.6.9.3 Test
5.6.9.4 Discussion/Requirements
5.6.10 Tensile Characterization Test
5.6.10.1 Purpose/Applicability
5.6.10.2 Preparations/Conditions
5.6.10.3 Test
5.6.10.4 Discussion/Requirements
5.6.11 Friction Coefficient Test
5.6.11.1 Purpose/Applicability
5.6.11.2 Preparations/Conditions
5.6.11.3 Test
5.6.11.4 Discussion/Requirements
Bibliography/References
6 Recommendations for Testing DC Extruded Cable Systems for Power Transmission at a Rated Voltage up to 500 kV
6.1 Introduction
6.1.1 Background
6.1.2 Scope
6.1.3 Revisions
6.1.4 Summary of Tests
6.1.5 Definitions
6.1.5.1 General
6.1.5.2 Test Objects
6.1.5.3 Test Voltages
6.1.5.4 Thermal Cable Design Parameters
6.1.5.5 Thermal Conditions for Tests
6.1.5.6 Conditions for Tests
6.1.5.6.1 Polarity Reversal Test (PR)
6.1.5.6.2 Superimposed Impulse Voltage Test
6.1.5.6.3 Check on Insulation Thickness of Cable
6.2 Development Tests
6.3 Prequalification Tests
6.3.1 Range of Approval
6.3.2 Summary of Prequalification Tests
6.3.3 Test Arrangement
6.3.4 Long Duration Voltage Test
6.3.5 Superimposed Switching Impulse Voltage Test
6.3.6 Examination
6.3.7 Success Criteria, Re-Testing and Interruptions
6.4 Type Tests
6.4.1 Range of Approval
6.4.2 Test Objects
6.4.3 Non-Electrical Type Tests
6.4.4 Electrical Type Test
6.4.4.1 Mechanical Preconditioning Before Electrical Type Test
6.4.4.2 Load Cycle Test
6.4.4.2.1 General
6.4.4.2.2 Load Cycle Test for Cable System to Be Qualified for LCC
6.4.4.2.3 Load Cycle Test for Cable System to Be Qualified for VSC
6.4.4.3 Superimposed Impulse Voltage Test
6.4.4.3.1 General
6.4.4.3.2 Switching Impulse Withstand Test for Cable System to Be Qualified for LCC
6.4.4.3.3 Switching Impulse Withstand Test for Cable System to Be Qualified for VSC
6.4.4.3.4 Lightning Impulse Withstand Test
6.4.4.3.5 Subsequent DC Test
6.4.4.4 Test of Outer Protection for Joints
6.4.4.5 Examination
6.4.4.5.1 Cable and Accessories
6.4.4.5.2 Cables with a Longitudinally Applied Metal Tape or Foil, Bonded to the Oversheath
6.4.4.6 Success Criteria, Re-Testing, and Interruptions
6.4.5 Return Cable Type Test
6.4.5.1 General
6.4.5.2 Mechanical Preconditioning
6.4.5.3 Thermo-Mechanical Preconditioning
6.4.5.4 AC Voltage Test
6.4.5.5 Lightning Impulse Withstand Test
6.4.5.6 Cable Design with Integrated Return Conductor
6.5 Routine Tests
6.5.1 Routine Tests on Transmission Cables
6.5.2 Routine Tests on Cable Accessories
6.5.2.1 Tests on Prefabricated Joints and Terminations
6.5.2.2 Tests on Factory Joints of Submarine Cables
6.5.2.3 Tests on Repair Joint for Submarine Cables
6.5.3 Return Cables or Conductors
6.6 Sample Tests
6.6.1 Sample Tests on Transmission Cables
6.6.1.1 Frequency of Tests
6.6.1.2 Conductor Examination
6.6.1.3 Measurement of Electrical Resistance of Conductor
6.6.1.4 Measurement of Capacitance
6.6.1.5 Measurement of Thickness of Insulation and Non-metallic Sheath
6.6.1.6 Measurement of Thickness of Metallic Sheath
6.6.1.7 Measurement of Diameters, if Required
6.6.1.8 Measurement of Density of HDPE Insulation, if Applicable
6.6.1.9 Impulse Voltage Test
6.6.1.10 Water Penetration Test, if Applicable
6.6.1.11 Tests on Components of Cables with Longitudinally Applied Metal Tape or Foil, Bonded to the Oversheath, if Applicable
6.6.2 Sample Tests on Factory Joints for Submarine Cables
6.6.2.1 Tensile Test
6.6.2.2 PD Measurement and AC Voltage Test
6.6.2.3 Impulse Voltage Test
6.6.2.4 Hot Set Test for Insulation Where Applicable
6.6.2.5 Pass Criteria
6.6.3 Sample Tests on Repair Joints and Terminations
6.6.4 Sample Tests on Field Molded Joints
6.7 After Installations Tests
6.7.1 High Voltage Test
6.7.2 Test on Polymeric Sheaths
6.7.3 TDR Measurement
6.7 Appendices
Appendix A: Derivation of Test Parameters
DC Voltage Factors
Impulse
Polarity Reversal
Duration of Tests: Prequalification & Type Tests
Appendix B: Technical Basis for the Detailed Prequalification Test Schemes
Appendix C: Schematic Representation of the Sequence of Tests for Land and Submarine Cables
Appendix D: Comparison with Guidelines and Recommendations for Transmission Cable Tests
References
7 Recommendations for Testing DC Transition Joints for Power Transmission at a Rated Voltage up to 500 kV
7.1 Introduction
7.1.1 Background
7.1.2 Scope
7.1.3 Condition Assessment
7.2 Definitions
7.2.1 Definitions of Tests
7.2.2 Test Cables and Transition Joint Characteristics
7.2.3 Definitions of Test Voltages
7.2.4 Thermal Cable Design Parameters
7.2.5 Thermal Conditions for Tests
7.2.6 Conditions for Test
7.3 Development Tests
7.3.1 Electrical Development Tests
7.3.2 Non-Electrical Development Tests
7.4 Routine Test
7.4.1 Extruded Cable Side of the Transition Joint
7.4.2 Paper Cable Side of the Transition Joint
7.4.3 Test on External Housing
7.5 Sample Test
7.6 Type Test
7.6.1 General
7.6.2 Range of Type Test Approval
7.6.3 Type Test Arrangement
7.6.4 Type Test Procedure
7.7 Prequalification Test
7.7.1 General and Range of Prequalification Test Approval
7.7.2 Summary of Prequalification Tests
7.7.3 Test Arrangement
7.7.4 Long Duration Voltage Test
7.7.5 Superimposed Impulse Voltage Test (Optional)
7.7.6 Examination
7.7.7 Success Criteria, Re-testing, and Interruptions
7.8 Electrical Test After Installation
7.8 Appendixes
Appendix A: Back-to-Back Transition Joint with Two Insulators
Appendix B: Temperature Distribution in Transition Joints with Dissimilar Cable Insulation
Appendix C: Terms of Reference of WG B1.42
References
8 Sheath Bonding Equipment for AC Transmission Cable Systems
8.1 Basic Information
8.1.1 Overview of Bonding Systems and Sheath Voltage Limiters
8.1.1.1 Cable Metal Screen Design and Screen Bonding
8.1.1.2 Sheath Insulation
8.1.1.3 Sectionalized Joints
8.1.1.4 Sheath Voltage Limiters
8.1.1.5 Link Boxes
8.1.1.6 Bonding and Grounding Leads
8.1.1.7 Safety Considerations
8.1.2 Review of Related Literature
8.1.2.1 Existing CIGRE Publications
8.1.2.1.1 Electra 28 and Electra 47
8.1.2.1.2 Electra 128
8.1.2.1.3 TB 283 Special Bonding of High Voltage Cables
8.1.2.1.4 TB 347 Earth Potential Rises in Specially Bonded Screen Systems
8.1.2.2 Technical Standards and Guides
8.1.2.2.1 IEEE 575
8.1.2.2.2 Engineering Recommendation C55/5
8.1.2.3 Relevant National Standards
8.1.2.4 IEC Standards
8.1.2.5 Cross References - Existing Standards
8.1.2.6 Published Papers
8.1.2.6.1 Sheath Voltage Calculations
8.1.2.6.2 Sheath Voltage Limiters
8.1.2.6.3 Field Measurements
8.1.2.6.4 State of the Art: Modern Bonding Methods
8.1.2.6.5 Safe Touch and Step Potential Design Requirements for Cable System Bonding and Earthing Designs
8.1.3 Review of Service Experience
8.1.3.1 Bonding Schematics
8.1.3.2 Withstand Voltage Level of Bonding Components
8.1.3.3 SVLs
8.1.3.4 Bonding Lead Cables
8.1.3.5 Link Boxes
8.1.3.6 Calculation Criteria
8.1.3.7 Tests During Installation
8.1.3.8 Maintenance Test
8.2 Bonding System Design and Protection
8.2.1 Bonding Designs
8.2.1.1 Solid or Multi-point Bonding
8.2.1.2 Single Point Bonding
8.2.1.3 Mid-point Bonding
8.2.1.4 Cross-Bonding
8.2.1.4.1 Continuous Cross-Bonding
8.2.1.4.2 Sectionalized Cross-Bonding
8.2.1.4.3 Cross-Bonding and Transposition
8.2.1.4.4 Direct Cross-Bonding
8.2.1.4.5 Cross-Bonding of Short Lines
8.2.1.5 Cross-Bonding in Tunnel Installations
8.2.1.6 Impedance Bonding
8.2.1.7 Siphon Lines
8.2.1.8 Bonding of Special Cable System Designs
8.2.1.8.1 Parallel Cable Systems
8.2.1.8.2 Multiple Cables per Phase
8.2.1.8.3 Cable Systems with a Fourth Conductor
8.2.1.9 Example of Induced Voltage Calculations of a Single Point Bonded System
8.2.1.10 Example of Circulating Current Calculations for a Solid Bonded System
8.2.1.11 Example of Circulating Current Calculations for a Cross-Bonded System with Two Minor Sections
8.2.2 Sheath Voltage Limiter Selection and Application
8.2.2.1 Sheath Voltage Limiters
8.2.2.2 Selection of Sheath Voltage Limiters
8.2.2.3 SVL Connection Configurations
8.2.2.4 SVL Installations
8.2.3 Cable System Models for Overvoltage Calculations
8.2.3.1 Cable Impedances and Admittances
8.2.3.2 Power Frequency Studies
8.2.3.2.1 CIM Method
8.2.3.2.2 NV Method
8.2.3.2.3 Symmetrical Component Analysis
8.2.3.3 Transient Studies
8.2.3.4 Modelling of Other Components
8.2.3.4.1 SVLs
8.2.3.4.2 Bonding Leads
8.2.3.4.3 Grounding
8.2.3.4.4 Overhead Lines
8.2.4 Insulation Coordination of Bonding Systems
8.2.4.1 Sheath Bonding System Insulation
8.2.4.2 Sheath Bonding System and Component Requirements
8.2.5 Special Protection on GIS Cable Terminations Against High Frequency Transient Overvoltage
8.3 Testing of Bonding Systems
8.3.1 Introduction and Section Scope
8.3.2 Testing of System Components
8.3.2.1 Cable Sheath Insulating Jacket
8.3.2.2 Sheath Interruption Insulators and Joint Casings
8.3.2.3 Bonding Leads
8.3.2.4 Sheath Voltage Limiters
8.3.2.5 Link Box or Enclosures
8.3.2.6 Mounting Insulators (Standoff Insulators) and GIS Insulation Flange for Terminations
8.3.3 System/Commissioning Tests
8.3.3.1 Induced Voltage and Bonding Test
8.3.3.2 Sheath Jacket Integrity Test
8.3.3.3 Contact Resistance Test
8.3.3.4 Others
8.4 Maintenance of Bonding Systems
8.4.1 Maintenance of Bonding Systems
8.4.2 Common Failure Modes
8.4.2.1 Jacket Damage
8.4.2.2 SVL Damage
8.4.2.3 Loose Connections (Bonding Leads, SVLs)
8.4.2.4 Damaged Bonding Leads
8.4.2.5 Link Box Failure
8.4.2.6 Stand-Off Insulator (Termination Support) Failure
8.4.2.7 Other Failure Modes
8.4.3 Corrective Maintenance of Bonding Systems
8.4.4 Preventative Maintenance of Bonding Systems
8.4.4.1 Online Maintenance
8.4.4.1.1 Patrolling
8.4.4.1.2 Sheath Current
8.4.4.1.3 SVL Integrity
8.4.4.1.4 Distributed Temperature Sensing (DTS)
8.4.4.1.5 Visual or Thermal Images
8.4.4.2 Offline Maintenance
8.4.4.2.1 Visual Inspection
8.4.4.2.2 Measurement of Resistance and Contact Resistance
8.4.4.2.3 SVL Integrity
8.4.4.2.4 Sheath Voltage Test
8.4.5 Maintenance Schedule of Bonding Systems
8.4.5.1 Safety Considerations During Maintenance
8.4.5.2 Parameters to Consider for Maintenance Planning
8.4.5.3 Recommendations for Maintenance Schedule for Cable Bonding Systems
8.5 Conclusions
8.5 Appendix A: Abreviations, Definitions, and Symbols
A1: Abbreviations
A2: Specific Terms
A3: Symbols
8.5 Appendix B
8.5 Appendix C
Appendix D: Bibliography/References
9 Maintenance and Remaining Life
9.1 Introduction
9.1.1 Background
9.1.2 Scope
9.1.3 Terms of Reference
9.1.3.1 To Review
9.1.3.2 To Analyze
9.1.3.3 To Propose
9.1.4 How to Read the Chapter
9.2 Existing Maintenance Practices
9.2.1 Introduction
9.2.2 Major Conclusions
9.2.2.1 Land Cable Systems AC and DC
9.2.2.2 Submarine Cable Systems AC and DC
9.2.2.3 Fluid Filled Cable Systems
9.2.2.4 Monitoring and Diagnostics
9.2.2.5 Future Developments
9.3 Maintenance Strategies
9.3.1 Introduction
9.3.2 Maintenance Strategies
9.3.3 Previous CIGRE Questionnaire
9.3.4 Summary
9.4 Maintenance on Land-Based Cable Systems (AC and DC)
9.4.1 Common Maintenance on Land-Based Cable Systems
9.4.1.1 Maintenance Activities to Prevent Third-Party Damages
9.4.1.2 Maintenance Activities on Cables
9.4.1.2.1 Inspections of Land Cable Systems
9.4.1.2.2 Maintenance Diagnostic Measurements
9.4.1.2.3 On-line Monitoring Activities
9.4.1.3 Maintenance Activities on Accessories
9.4.1.3.1 Maintenance Activities on Terminations
9.4.1.3.1.1 All Types of Terminations
9.4.1.3.1.2 Outdoor Installed Terminations
9.4.1.3.1.3 Fluid-Filled/Gas-Filled Terminations
9.4.1.3.2 Maintenance Activities on Joints
9.4.1.3.2.1 Hot Spot Temperature Measurement of Joints (Tunnel, Manholes)
9.4.1.3.2.2 Visual Inspections of Joints (e.g., in Tunnels, Shafts/Pits, Manholes)
9.4.1.3.2.3 Joint Sectioning Test (Only in Joints with Screen Separation)
9.4.1.3.2.4 PD Detection (One-Off Measurements)
9.4.2 Maintenance Activities on Specially Bonded Systems
9.4.3 Additional Maintenance for HVDC Cable Systems
9.4.3.1 Additional Maintenance Activities on Cables
9.4.3.2 Additional Maintenance Activities on Accessories
9.4.3.2.1 Terminations
9.4.3.2.2 Joints
9.4.3.3 Fault Finding on Long HVDC Systems
9.4.4 Corrective Maintenance
9.4.5 Tunnels
9.4.5.1 Cable Design and Impact on Maintenance
9.4.5.2 Tunnel Design and Impact on Maintenance
9.4.5.3 Maintenance Activities and Procedures in Tunnels
9.5 Maintenance on Submarine Cable Systems (AC and DC)
9.5.1 Preventive Maintenance on Submarine Cable Systems
9.5.1.1 Maintenance Activities to Prevent Third-Party Damages
9.5.1.2 Maintenance Activities to Control Cable Protection and Health
9.5.1.2.1 Offshore Surveys
9.5.1.2.2 Landfall Inspection
9.5.1.2.3 Cable System Inspection on Platforms
9.5.1.2.4 Measurements and Monitoring with Fiber Optics
9.5.1.3 Maintenance Activities on Submarine Mechanical Protections
9.5.2 Corrective Maintenance on Submarine Cable Systems
9.5.2.1 Immediate Actions After Fault Occurrence
9.5.2.2 Preparation of Repair Works
9.5.2.3 Mobilization of Resources for Repair Works
9.5.2.4 Repair Works
9.6 Fluid Filled Cable Systems
9.7 Monitoring and Diagnostics
9.7.1 Introduction
9.7.1.1 Effective Maintenance Actions to Ensure Availability of a Cable System
9.7.1.2 Effective Measurements to Determine Condition of a Cable System
9.7.2 Overview of Different Techniques
9.7.3 Description of the Methods
9.7.3.1 AC or DC Voltage Test
9.7.3.2 PD Measurement
9.7.3.3 DC Insulation Resistance Measurement
9.7.3.4 Dissipation Factor Measurement (Tan Delta) and Dielectric Spectroscopy (DS)
9.7.3.5 DC Voltage Test on Oversheath
9.7.3.6 Bonding Performance Test and Monitoring of Screen Voltage and Current
9.7.3.7 Sheath Voltage Limiters (SVLs) Test*
9.7.3.8 Earthing Resistance Measurement
9.7.3.9 Loop and Contact Resistance Measurement
9.7.3.10 DC Conductor Resistance Measurement
9.7.3.11 Capacitance Measurement
9.7.3.12 Sequence Impedance Measurement
9.7.3.13 Inspection of Manometers and Plumbing
9.7.3.14 Oil Leak Detection and Localization
9.7.3.15 Oil Analysis: Dissipation Factor Measurement
9.7.3.16 Infrared Temperature Measurement
9.7.3.17 Localized Temperature Measurement
9.7.3.18 Distributed Temperature Sensing/Measurement (DTS)
9.7.3.19 Time Domain Reflectometry (TDR)
9.7.3.20 Frequency Domain Reflectometry (FDR)
9.7.3.21 Cathodic Protection Performance
9.7.3.22 Oil/Gas Pressure
9.7.3.23 Distributed Acoustic Sensing (DAS)
9.7.3.24 Cable Bathymetric Survey
9.7.3.25 Impregnation Coefficient
9.7.3.26 Insulation Sample Testing
9.8 Spare Parts Management, Emergency Preparedness, and Training
9.8.1 Spare Parts Management
9.8.1.1 Context
9.8.1.2 Identification of the Critical Parts to Be Kept Available
9.8.1.3 Provision of Spare Parts
9.8.1.4 Spare Parts Sizing
9.8.1.5 Inter-compatibility of Spares
9.8.1.6 Spare Parts Storage and Quality Assurance
9.8.2 Emergency/Repair Preparedness Plan
9.8.2.1 Introduction
9.8.2.2 Questions That the Cable Owner/Operator May Face upon a Cable Failure
9.8.2.3 Emergency Preparedness Plan (EPP) or Repair Preparedness Plan (RPP)
9.8.2.4 Important Issues to Address in the Cable Supply Contract
9.8.2.5 Contracting Strategies
9.8.2.5.1 Rely on Turn-Key Solutions
9.8.2.5.2 Rely on In-House Resources and Multiple Contract Management
9.8.2.6 Service Level Agreement
9.8.3 Skilled Personnel and Training
9.9 Cost of Maintenance
9.9.1 Introduction
9.9.2 Labor Cost: Preventive Maintenance
9.9.2.1 Reduce Preventive Maintenance Activities
9.9.2.2 Transfer from Time-Based Maintenance Towards Condition-Based Maintenance
9.9.2.3 Use of Monitoring Techniques Which Replaces Preventive Maintenance Activities
9.9.3 Monitoring and Diagnostic Costs
9.9.4 Offshore Surveys
9.9.5 Repair Cost
9.9.5.1 Mobilization Cost
9.9.5.2 Material Cost
9.9.5.3 Civil Works Cost
9.9.5.4 Labor Cost
9.9.5.5 Indirect Costs
9.9.6 Service Level Agreement Costs
9.9.7 Costs of Storage and Maintaining Spare Parts in Operational Conditions
9.9.8 Conclusions
9.10 Maintenance and Remaining Life
9.10.1 Background
9.10.2 Remaining Life Estimation
9.10.3 Criteria for End of Life
9.10.4 Failure Rate Calculation
9.10.4.1 Global Failure Rate
9.10.4.2 Failure Rate per Age
9.10.5 Health Index
9.10.5.1 Introduction
9.10.5.2 Condition Assessment Approaches
9.10.6 Examples: Retirement Strategies
9.10.6.1 Retirement Options for Fluid Filled Cables
9.10.6.2 Retirement Options for Pipe-Type Cables
9.11 Future Developments
9.11.1 From Time-Based Maintenance Toward Condition-Based Maintenance
9.11.2 New Methods for Condition-Based Maintenance
9.11.3 Data Collection
9.11.4 Satisfaction with Diagnostic Methods and Data Collection
9.12 Recommendations and Conclusions
9.12.1 General Recommendations
9.12.1.1 Carry Out Cable Maintenance with a Clear Strategy
9.12.1.2 Maintenance Strategy Based upon Statistical Analyses
9.12.1.3 Diagnostic Measurements and Monitoring Techniques
9.12.1.4 Keep Maintenance Strategy Under Review
9.12.2 Recommendations for Specific Cable Types
9.12.2.1 Land Cable Systems
9.12.2.2 Submarine Cable Systems
9.12.3 Summary
9.12 Appendix A. Definitions and Abbreviations
General Terms
Specific Terms
9.12 Appendix B. Links and References
Standards
CIGRE Technical Brochures
Papers and Contributions
9.12 Appendix C. Case Studies for Lack of Space, This Appendix is not Reproduced in This Chapter of the Book
9.12 Appendix D. Case Studies for Lack of Space, This Appendix is not Reproduced in This Chapter of the Book