Accessories for HV and EHV Extruded Cables: Components

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 Compendium of Accessory Types Used for AC HV Extruded Cables
1.1 Introduction
1.2 Types of Joints
1.2.1 Types of Straight Joints
1.2.1.1 ``Taped´´ Joints
1.2.1.2 ``Prefabricated´´ Joints
1.2.1.3 ``Field Moulded´´ Joints
1.2.1.4 ``Heat Shrink Sleeve´´ Joint
1.2.1.5 ``Back-to-Back´´ Joint
1.2.2 Types of Transition Joints
1.2.2.1 ``Polymeric Extruded Cable to Mass Impregnated Cable´´ Transition Joint
1.2.2.2 ``Polymeric Extruded Cable to Oil or Gas Filled Paper Cable´´ Transition Joint, Three Core Type
1.2.2.3 ``Polymeric Extruded Cable to Oil or Gas Filled Paper Cable´´ Transition Joint, Single Core ``Non-Fed´´ Type
1.2.2.4 ``Polymeric Extruded Cable to Oil or Gas Filled Paper Cable´´ Transition Joint, Single Core ``Fed´´ Type
1.2.3 Types of Y Branch Joints
1.3 Types of Terminations
1.3.1 Types of Metal Enclosed GIS Terminations
1.3.1.1 ``Stress Cone and Insulator´´ Metal Enclosed GIS Termination
1.3.1.2 ``Deflector and Insulator´´ Metal Enclosed GIS Termination
1.3.1.3 Prefabricated Composite ``Dry´´ Metal Enclosed GIS Termination
1.3.1.4 ``Capacitor Cone and Insulator´´ Metal Enclosed GIS Termination
1.3.1.5 ``Directly Immersed´´ Metal Enclosed GIS Termination
1.3.2 Types of ``Oil Immersed Transformer´´ Terminations
1.3.2.1 ``Stress Cone and Insulator´´ Oil Immersed Transformer Termination
1.3.2.2 ``Deflector and Insulator´´ Oil Immersed Transformer Termination
1.3.2.3 Prefabricated Composite ``Dry´´ Oil Immersed Transformer Termination
1.3.2.4 ``Capacitor Cone and Insulator´´ Oil Immersed Transformer Termination
1.3.2.5 ``Directly immersed´´ Oil Immersed Transformer Termination
1.3.3 Types of Outdoor Terminations
1.3.3.1 ``Prefabricated´´ Elastomeric Sheds and Stress Cone Outdoor Termination
1.3.3.2 ``Heat Shrink Sleeve´´ Outdoor Termination
1.3.3.3 ``Elastomeric Sleeve´´ Outdoor Termination
1.3.3.4 ``Stress Cone and Insulator´´ Outdoor Termination
1.3.3.5 ``Deflector and Insulator´´ Outdoor Termination
1.3.3.6 ``Prefabricated Composite and Insulator´´ Outdoor Termination
1.3.3.7 ``Capacitor Cone and Insulator´´ Outdoor Termination
1.3.3.8 ``Prefabricated Composite and Capacitor Cone, and Insulator´´ Outdoor Termination
1.3.4 Types of Indoor Terminations
1.3.4.1 ``Prefabricated´´ Elastomeric Sheds and Stress Cone Indoor Termination
1.3.4.2 ``Heat Shrink Sleeve´´ Indoor Termination
1.3.4.3 ``Elastomeric Sleeve´´ Indoor Termination
1.3.4.4 ``Stress Cone and Insulator´´ Indoor Termination
1.3.4.5 ``Deflector and Insulator´´ Indoor Termination
1.3.4.6 ``Prefabricated Composite and Insulator´´ Indoor Termination
1.3.4.7 ``Capacitor Cone and Insulator´´ Indoor Termination
1.3.4.8 ``Prefabricated Composite and Capacitor Cone, and Insulator´´ Indoor Termination
1.3.5 Types of Temporary Terminations
1.3.5.1 ``Prefabricated Elastomeric Sheds and Stress Cone´´ Temporary Termination
1.3.5.2 ``Heat Shrink Sleeve´´ Temporary Termination
1.3.5.3 ``Elastomeric Sleeve´´ Temporary Termination
1.3.5.4 ``Stress Cone and Insulator´´ Temporary Termination
1.3.5.5 ``Deflector and Insulator´´ Temporary Termination
1.3.5.6 ``Prefabricated Composite and Insulator´´ Temporary Termination
1.3.5.7 ``Capacitor Cone and Insulator´´ Temporary Termination
1.3.5.8 ``Prefabricated Composite and Capacitor Cone and Insulator´´
Appendix: Glossary of Component Names
Glossary of Names for Components Used in Accessories for Extruded Cables
2 A Guide to the Selection of Accessories
2.1 Introduction
2.2 Compatibility of the Accessory with the Cable
2.2.1 Number of Cable Cores
2.2.2 Cable Constructional Details
2.2.3 Conductor Area and Diameter
2.2.4 Operating Temperature of the Cable Conductor and Sheath under Continuous, Short Term Overload and Short Circuit Current ...
2.2.5 Compatibility of the Accessory with the Type of Cable Insulation and Semiconducting Screens
2.2.5.1 Physical Compatibility with the Extruded Cable
2.2.5.2 Chemical Compatibility with the Extruded Cable
2.2.5.3 Compatibility with the Paper Insulated Cable
2.2.6 Cable Electrical Design Stresses to be Withstood by the Accessory
2.2.7 Mechanical Forces and Movements Generated by the Cable on the Accessory
2.2.8 Short Circuit Forces
2.3 Compatibility of the Accessory Performance with that of the Cable System
2.3.1 Circuit Performance Parameters
2.3.2 Circuit Life Required
2.3.3 Metallic Screen Bonding Requirements
2.3.4 Earth Fault Requirements
2.4 Compatibility of the Accessory with the Cable System Design and Operating Conditions
2.4.1 Type of Cable Installation Design
2.4.2 Standard Dimensions for Cable Termination
2.4.3 Type of Accessory Installation Environment
2.4.4 Jointing Limitations in Restricted Installation Locations
2.4.5 Mechanical Forces Applied to the Accessory
2.4.6 Climatic Conditions
2.4.7 Type of Accessory Outer Protection Required
2.4.8 Situations Requiring Special Accessory Protection
2.5 Verification of Accessory Performance
2.5.1 Use of the Specific National or International Type Test Specification for the Accessory
2.5.2 Use of the Cable Test Specification in the Absence of an Accessory Specification
2.5.3 Type Test Report
2.5.4 Type Tested Accessory in Combination with the Particular Cable
2.5.5 Pre-Qualification Tests
2.5.6 Satisfactory Service Record
2.5.7 Test for Accessories in Specially Bonded Cable Circuits
2.5.8 Tests for Water Tightness of Joints
2.5.9 Additional Tests for Cable Terminations
2.5.10 Pressure Vessel Regulations
2.6 Quality Assurance Scheme for Accessory Design and Manufacture
2.6.1 The Routine Test Schedule
2.6.2 Quality Assurance Approval for Manufacture
2.6.3 Routine Tests on Prefabricated Moulded Insulation
2.6.4 Sample Tests on Individual Components
2.7 Quality Assurance Scheme for Accessory Installation
2.7.1 Quality Assurance Approval for Installation
2.7.2 Quality Plan
2.7.3 Training of Personnel
2.7.4 Assembly Instructions
2.7.5 Special Assembly Tools
2.7.6 Preparation of the Assembly Environment
2.7.6.1 Joint Assembly
2.7.6.2 Termination Assembly
2.8 Compatibility of the Accessory with Specified after Laying Tests
2.8.1 Voltage Test on Main Insulation
2.8.2 Partial Discharge Detection
2.8.3 Voltage Withstand Test on the Cable over Sheath and Joint Protection
2.8.4 Current Balance Test on the Cable Sheath and Screening Wires
2.9 Maintenance Requirements of the Accessory
2.9.1 Monitoring of Fluid Insulation
2.9.2 Voltage Withstand Tests on the over Sheath and Joint Protection
2.9.3 Shelf Life of Accessories for Emergency Spares
2.9.4 Availability of Accessory Kits for Emergency Spares
2.10 Economics of Accessory Selection
2.10.1 Cost of the Accessory Complete with all Components
2.10.2 Cost of Guarantee and Insurance
2.10.3 Cost of Assembly Time
2.10.4 Cost of Preparing the Installation Environment for the Accessory
2.10.5 Cost of Safe Working Conditions
2.10.6 Cost of Special Jointing Tools
2.10.7 Cost of Training
2.10.8 Comparative Cost of Cable and Accessories
2.10.9 Cost of Verification of Accessory Performance
References
3 Interfaces in Accessories for Extruded HV and EHV Cables
3.1 Introduction
3.1.1 Terms of Reference of JTF 21/15
3.1.2 Interfaces to be Studied
3.1.3 Materials Involved
3.2 Interface Parameters
3.2.1 Smoothness of the Surfaces
3.2.2 Contact Pressure
3.2.3 Lubricant
3.2.4 Electrical Field Distribution
3.2.5 Temperature and Temperature Changes
3.2.6 Quality of Accessory Installation
3.3 Long Term Performance of Interfaces in Cable Accessories
3.3.1 Migration of the Lubricant
3.3.2 Movements in the Interface
3.3.3 Reduction of the Interface Pressure due to Relaxation of Materials
3.3.4 Electrical Ageing of Interfaces
3.4 Testing
3.5 Recommendations and Conclusions
References
4 Qualification Procedures for HV and EHV AC Extruded Underground Cable Systems
4.1 Introduction
4.1.1 General
4.1.2 Scope and Terms of Reference of WG B1.06
4.1.3 Experience
4.1.3.1 Ageing of Extruded Polymeric Insulation
4.1.3.2 Experience with HV Extruded Cable Systems up to and Including 150 kV
4.1.3.3 Experience with EHV Extruded Cable Systems at Voltages above 150 kV
4.1.3.3.1 Prequalification Test Experience
4.1.3.3.2 Service Experience
4.2 Long Duration Test on EHV Cable Systems (170 < Um < 550 kV)
4.2.1 General
4.2.2 Revision of the Present Prequalification Test Procedure
4.2.2.1 Duration of the Heating Cycle Voltage Test
4.2.2.2 Procedure in Case of a System Component (Cable and/or Accessory) Failure during the Test
4.2.2.3 Final Control Test
4.2.3 Changes in a Prequalified Cable System
4.2.3.1 Evaluation of Changes in a Prequalified System
4.2.3.1.1 Exchange of Cable and/or Accessory in a Prequalified Cable System
4.2.3.1.2 Modification to the Cable in a Prequalified Cable System
4.2.3.1.3 Modification to an Accessory within the Same Family in a Prequalified Cable System
4.2.3.2 Basic Principles of the Extension of Prequalification (EQ) Test
4.2.3.3 Procedure of the Extension of Prequalification Test
4.2.4 Recommendations to IEC 62067
4.3 Long Duration Test on HV Cable Systems (36 < Um 170 kV)
4.3.1 General
4.3.2 Prequalification Test for HV Systems
4.3.2.1 Range of Prequalification Test
4.3.2.2 Prequalification Test Procedure
4.3.3 Exchanges and Modifications in a Prequalified HV Cable System
4.3.3.1 Evaluation of Changes and Modifications in a Prequalified System
4.3.3.2 Procedure of the Extension of Prequalification (EQ) Test for HV Cable Systems
4.3.4 Recommendations to IEC 60840
4.4 Conclusions
4.5 Annexes
4.5.1 Terms of Reference
4.5.1.1 Title
4.5.1.2 Scope
4.5.1.3 Terms of reference
4.5.2 Sensitivity of Partial Discharges in XLPE Cable Insulation to Change of Electrical Stress
4.5.2.1 Introduction
4.5.2.2 Cable Standards and Insulation Stress
4.5.2.3 Sensitivity of Insulation Stress to Change of Cable Dimensions
4.5.2.3.1 Sensitivity to Change of Inner Radius
4.5.2.3.2 Sensitivity to Change of Insulation Width
4.5.2.3.3 Sensitivity Per Unit
4.5.2.3.4 Numerical Example
4.5.2.4 Determination of Risk of Discharge Caused by Change of Dimensions
4.5.2.4.1 Size of Discharge-free Defects
4.5.2.4.2 Size Sensitivity of Discharge Free Defects to Change of Field Strength
4.5.2.5 Effect of Change of Cable Dimensions on Discharge Free Operation
4.5.2.5.1 Cable Systems with ``Slim´´ Design
4.5.2.5.2 Cable Systems with Increased Conductor Size
4.5.2.6 Conclusions
4.5.2.6.1 ``Slim´´ Design
4.5.2.6.2 Increased Conductor Size
4.5.2.6.3 Conclusion
4.5.3 Functional Analysis
4.5.3.1 Introduction
4.5.3.2 Functional Analysis Method
4.5.3.3 Functional Analysis Tables
4.5.3.3.1 Remark
4.5.4 Tests From Functional Analysis not in IEC
4.6 References
5 Cable Accessory Workmanship on Extruded High Voltage Cables
5.1 Summary
5.2 Introduction
5.3 Scope
5.3.1 Inclusions
5.3.2 Exclusions
5.4 Related Literature and Terminology
5.4.1 Related Literature
5.4.2 Additional Terminology
5.5 General Risks and Skills
5.6 Technical Risks and Required Specific Skills
5.6.1 Conductors
5.6.1.1 Conductor Preparation
5.6.1.2 Compression
5.6.1.3 MIG/TIG Welding
5.6.1.4 Thermit Weld
5.6.1.5 Mechanical Connection
5.6.2 Insulation Preparation
5.6.2.1 Straightening
5.6.2.1.1 Cold Straightening
5.6.2.1.2 Hot Straightening
5.6.2.2 Stripping of Insulation Screen
5.6.2.2.1 Peeling
5.6.2.2.2 Scraping
5.6.2.2.3 Hot Stripping
5.6.2.3 Preparing the End of the Insulation Screen
5.6.2.4 Smoothening the Insulation Surface
5.6.2.4.1 Polishing
5.6.2.4.2 Melting
5.6.2.5 Cleaning of Insulation
5.6.2.6 Shrinkage
5.6.2.7 Lubrication
5.6.3 Metallic Sheath
5.6.3.1 Welded Aluminium Sheath (WAS)
5.6.3.1.1 Preparation of Cable Sheath
5.6.3.1.2 Metallic Sheath Continuity
Connection on Outside of the Aluminium Sheath
Connection under the Aluminium Sheat
Additional Copper Wire Insulation Screen
Reinforcement
5.6.3.2 Corrugated Sheaths: Aluminium (CAS); Copper (CCS); Stainless Steel (CSS)
5.6.3.2.1 Preparation of Cable Sheath
5.6.3.2.2 Metallic Screen Continuity
Plumbing
Soldering
5.6.3.2.3 Additional Copper Wire Insulation Screen
5.6.3.2.4 Reinforcement
5.6.3.3 Lead Sheath
5.6.3.3.1 Preparation of Cable Sheath
5.6.3.3.2 Metallic Screen Continuity
5.6.3.3.3 Additional Copper Wire Insulation Screen
5.6.3.3.4 Reinforcement
5.6.3.4 Laminated Sheaths: Aluminium Polyethylene Laminate (APL); Copper Polyethylene Laminate (CPL)
5.6.3.4.1 Preparation of Cable Sheath
5.6.3.4.2 Metallic Screen Continuity
5.6.3.4.3 Additional Copper Wire Insulation Screen
5.6.4 Oversheath
5.6.4.1 Case of Graphite Coating
5.6.4.2 Case of Extruded and Bonded Semi-Conducting Layer
5.6.4.3 Low Smoke, Zero Halogen, Enhanced Flame Performance Sheaths
5.6.5 Installation of Joint Electric Field Control Components
5.6.5.1 Slip on Prefabricated Joint
5.6.5.2 Expansion Joints
5.6.5.3 Field Taped Joints
5.6.5.4 Field Moulded Joints (Extruded or Taped)
5.6.5.5 Heatshrink Sleeve Joint
5.6.5.6 Prefabricated Composite Type Joint
5.6.5.7 Plug-in Joint
5.6.5.8 Pre-moulded Three Piece Joint
5.6.6 Installation of Termination Electric Field Control Components
5.6.6.1 Slip-on Prefabricated Field Control Components
5.6.6.2 Plug-in Terminations
5.6.6.3 Taped Terminations
5.6.6.4 Heatshrink Sleeve Insulated Terminations
5.6.6.5 Prefabricated Composite Dry Terminations
5.6.7 Outer Protection of Joints
5.6.7.1 Polymeric Outer Protection by Taping and/or Heatshrink Tubes
5.6.7.2 Outer Protection Assembly
5.6.7.3 Filling Compounds for Joint Protections (Joint Boxes)
5.6.8 Filling of Terminations
5.6.9 Handling of Accessories
5.6.9.1 Supporting of Accessory
5.6.9.2 Lifting of Accessories
5.6.9.3 Special Bonding Configurations and Link Box Installation
5.6.9.4 Sensor Connections
5.6.9.5 Fibre Optics
5.7 Skills Assessment
5.7.1 Aspects to be Tested
5.7.2 Methods of Qualification
5.7.2.1 Theoretical
5.7.2.2 Training on the Job and Observation
5.7.2.3 Testing: Electrical & Mechanical
5.7.3 Certification
5.7.4 Duration of Certification
5.7.5 Upskilling
5.7.6 New Accessory Type
5.8 Set Up
5.8.1 Organisation of Jointing Location
5.8.2 Positioning of Joint
5.8.3 Environmental Conditions
5.8.4 Cable End Inspection
5.8.5 Verification of Each Step
5.8.6 Measuring of Diameters, Ovality, Concentricity, Position
5.8.7 Safety and Health
5.8.8 Environmental Aspects
5.8.9 Quality Insurance
Appendix A: Model Certificate
Appendix B: QA Document
References
6 Guidelines for Maintaining the Integrity of Extruded Cable Accessories
6.1 Review of Recent Experience with Failures of Outdoor and Filled Terminations and Non-buried Joints
6.1.1 Review of Literature
6.1.1.1 Cigré, Jicable and Other Technical Literature
6.1.1.2 Statistics
6.1.1.3 Workmanship
6.1.2 Review the Consequences of Termination Failures for Cables within Substations and Outside
6.1.2.1 Cigré, Jicable and other Technical Literature
6.1.2.2 Statistics
6.1.2.3 Workmanship
6.1.3 Survey by B1-29
6.1.3.1 Survey on Terminations
6.1.3.2 Survey on Non-buried Joints
6.2 The Role of Improved Materials, Design, Assembly and Quality Control in Mitigating the Effects of Termination and Non-buri...
6.2.1 Survey Results
6.2.1.1 Terminations
6.2.1.1.1 Design
6.2.1.1.2 Manufacture
6.2.1.1.3 Workmanship
6.2.1.1.4 Overvoltage
6.2.1.1.5 Weather Effects
6.2.1.1.6 Bonding Problems
6.2.1.1.7 Fluid/Gas Problems
6.2.1.1.8 Others
6.2.1.2 Non-buried Joints
6.2.1.2.1 Design
6.2.1.2.2 Manufacture
6.2.1.2.3 Workmanship
6.2.1.2.4 Overvoltage
6.2.1.2.5 Weather Effects
6.2.2 Design and Materials
6.2.2.1 Air Insulated Terminations
6.2.2.1.1 Porcelain Insulators
6.2.2.1.2 Composite or Polymeric Insulators
6.2.2.1.3 Latest Developments
6.2.2.2 GIS and Oil Immersed Terminations
6.2.2.3 Insulation Medium
6.2.2.4 Connectors
6.2.2.4.1 Compression Connector
6.2.2.4.2 Cad Welding
6.2.2.4.3 Soldered or Brazed Connector
6.2.2.4.4 MIG or TIG Welded Connection
6.2.2.4.5 Plug-in Connector
6.2.2.4.6 Mechanical Bolted Connector (Shear Bolts)
6.2.2.4.7 Mechanical Bolted Connector
6.2.2.5 Non-buried Joints
6.2.3 Assembly
6.2.4 Quality Control
6.3 The Role of Testing and Condition Monitoring in Minimising the Incidence or Severity of Termination and Non-buried Joint F...
6.3.1 Testing
6.3.1.1 General
6.3.1.2 Development Testing
6.3.1.2.1 Insulators
6.3.1.2.2 Connectors
6.3.1.2.3 Filling Fluids
6.3.1.3 Prequalification Test
6.3.1.4 Type Test
6.3.1.5 Short Circuit Tests
6.3.1.6 Sample Tests
6.3.1.7 Routine Tests
6.3.1.8 Tests on Filling Materials
6.3.1.9 Commissioning Tests
6.3.2 Condition Monitoring
6.4 Recommendations
6.4.1 Existing Circuits
6.4.2 New Circuits
6.5 Conclusions
Appendix 1: Terms of Reference
Appendix 2: Bibliography/References
IEC Standards
CIGRE
Jicable
Appendix 3: Reminder Chapter 5/TB 476
Appendix 4: Short Circuit Tests
Low Energy External Fault (Through-fault i.e. Breakdown Outside the Accessory)
Simulation of the Fault
Position of the Fault
External Fault Withstand Test
Requirements
High Energy Internal Fault (Internal Fault i.e. Breakdown Inside the Accessory)
Simulation of the Fault
Position of the Fault
Internal Fault Withstand Test
Requirements
Appendix 5: Condition Monitoring Techniques for Terminations and Non-buried Joints
7 Feasibility of a Common, Dry Type Plug-in Interface for GIS and Power Cables above 52 kV
7.1 Introduction and Scope
7.1.1 Scope
7.2 Definitions
7.2.1 General Layout
7.2.2 Definitions and Terms (According to IEC 62271-209)
7.2.2.1 Cable-Termination (IEC 62271-209)
7.2.2.1.1 Fluid-Filled Cable-Termination (IEC 62271-209)
7.2.2.1.2 Dry-Type Cable-Termination (IEC 62271-209)
7.2.2.2 Plug-in Cable Termination
7.2.2.2.1 Locked Plug-in Type Cable Termination
7.2.2.2.2 Plug-in, Plug-out Type Cable Termination
7.2.2.2.3 Locking Plug-in, Plug-out Type Cable Termination
7.2.2.3 Insulator Assembly
7.2.2.4 Insulator
7.2.2.5 Plug-in Connector of Insulator
7.2.2.6 Plug-in Connector of Cable
7.2.2.7 Main-Circuit End Terminal (IEC 62271-209 and Compliant with IEEE 1300)
7.2.2.8 Cable Connection Enclosure (IEC 62271-209 and Compliant with IEEE 1300)
7.2.2.9 Cable Connection Assembly (IEC 62271-209 and Compliant with IEEE 1300)
7.2.2.10 Cable System (IEC 62271-209)
7.2.3 Units
7.2.3.1 Pressure
7.2.3.2 Rated Voltages (IEC 60840 and 62271)
7.3 Experience
7.3.1 GIS Cable Terminations Installation Examples
7.3.1.1 Um 362 ~ 550 kV
7.3.1.1.1 Vertical Installations
7.3.1.1.2 Horizontal Installations
7.3.1.1.3 Inclined Installations
7.3.1.2 Um 245 ~ 300 kV
7.3.1.2.1 Vertical Installation
7.3.1.3 Um 123 ~ 170 kV
7.3.1.3.1 Vertical Installation
7.3.1.3.2 Horizontal Installation
7.3.1.4 Um 72.5 ~ 100 kV
7.3.1.4.1 Vertical Installation
7.3.2 Experience of Dry Type Insulator
7.3.2.1 History of Dry Plug-in Termination
7.3.2.2 German Experience of Plug-in Plug-out Interchangeable GIS Termination
7.3.2.3 USA Experience
7.4 Design of Dry Type GIS Terminations
7.4.1 Differences in Design of Barrier Insulator, Inner Cone Type
7.4.2 Differences in Design of Barrier Insulator, Outer Cone Type
7.4.3 Requirements for Standardization of a Common Interface
7.4.3.1 Insulator
7.4.3.1.1 Dimensions and Tolerances
7.4.3.1.2 Dielectric Parameters
7.4.3.1.3 Mechanical Parameters
7.4.3.1.4 Routine Test
7.4.3.1.5 Type Test and Prequalification Test
7.4.3.2 Stress Cone
7.4.3.2.1 Design Considerations
7.4.3.2.2 Routine Test
7.4.3.2.3 Type Test and Prequalification Test
7.4.3.3 Plug in Connector and Other Parts of the Termination
7.4.3.3.1 Type Test
7.5 Where the Plug-in Concept Could Be Applicable
7.5.1 Geometrical Installation Constraints
7.5.1.1 GIS Termination Installation Procedures
7.5.1.2 Civil Work Constraints
7.5.1.2.1 Height Between the Bottom of Metal Enclosure/Epoxy Insulator and Lower Floor
7.5.1.2.2 Free Space for Cable Snaking Necessary for Plug-in Operation
7.5.1.2.3 Free Space for Cable Snaking Necessary in Case of an Intermediate Floor
7.5.1.2.4 Floor Hole Size when Cable Is Crossing an Intermediate Floor
7.5.1.3 Conclusions Regarding Geometrical Installation Constraints
7.5.2 Safety Practices and Constraints during Installation
7.5.2.1 Voltage
7.5.2.2 Gas Pressure during Installation
7.5.3 Testing Constraints
7.5.3.1 Tests on Insulator Before Supply
7.5.3.2 Tests of the Stress Cone on a Cable Termination Assembly with a Host Insulator
7.5.3.3 Tests After Installation
7.5.4 Conclusion Regarding Testing Constraints
7.6 Qualification
7.6.1 State of the Art
7.6.1.1 Medium Voltage Standards
7.6.1.2 Medium Voltage Qualification Experience
7.6.1.3 High Voltage Standards
7.6.2 Where the Plug-in Common Interface Could be Applicable
7.6.3 Qualification of new Insulator or Stress Cone
7.7 Feasibility
7.7.1 Definition Feasibility (Cost Involved)
7.7.2 Qualification Feasibility
7.8 Market Acceptance
7.8.1 Current Status
7.8.2 Future Status
7.8.3 Where the Plug-in Common Interface Could be Recommended
7.9 Conclusion and Recommendations
References
8 Test Procedures for HV Transition Joints for Rated Voltages 30 kV up to 500 kV
8.1 Introduction
8.1.1 General
8.1.2 Background
8.1.3 Scope
8.1.4 Condition Assessment
8.2 Normative References
8.3 Definition of Tests
8.3.1 Development Tests
8.3.2 Routine Test
8.3.3 Sample Test
8.3.4 Type Test
8.3.5 Prequalification Test
8.3.6 Electrical Test after Installation
8.4 Test Cables and Transition Joint Characteristics
8.5 Development Tests
8.5.1 Electrical Development Tests
8.5.2 Non-Electrical Development Tests
8.6 Routine Test
8.6.1 Extruded Cable Side of the Transition Joint
8.6.2 Paper Cable Side of the Transition Joint
8.7 Sample Test
8.8 Type Test
8.8.1 General
8.8.2 Range of Type Test Approval
8.8.3 Type Test Arrangement
8.8.4 Type Test Procedure
8.8.4.1 Test Voltage Values
8.8.4.2 Tests and Sequence of Tests
8.8.4.3 Partial Discharge Measurements
8.8.4.4 Heating Cycle Voltage Test
8.8.4.5 Impulse Voltage Tests
8.8.4.5.1 Switching Impulse Voltage Test
8.8.4.5.2 Lightning Impulse Voltage Test Followed by a Power Frequency Voltage Test
8.8.4.6 Tests of Outer Protection for Buried Joints
8.8.4.7 Pressure Leak Test
8.8.4.7.1 Leak Test
8.8.4.7.2 Pressure Test
8.8.4.8 Examination
8.9 Prequalification Test
8.9.1 General and Range of Prequalification Test Approval
8.9.2 Prequalification Test Arrangement
8.9.3 Prequalification Test Procedure
8.9.3.1 Test Voltage Values
8.9.3.2 Tests and Sequence of Tests
8.9.3.3 Heating Cycle Voltage Test
8.9.3.4 Lightning Impulse Voltage Test
8.9.3.5 Examination
8.10 Electrical Test after Installation
8.10.1 DC Voltage Test of the Oversheath
8.10.1.1 New Cable Section with Extruded Insulation
8.10.1.2 Existing Cable Section (Paper-Insulated)
8.10.2 AC Voltage Test of the Insulation
Appendix A Considerations for Transition Joints for Other Types of Paper Cable
A.1 Cables to IEC 60141-2: - Internal Gas-Pressure Cables and their Accessories for Alternating Voltages up to 275 kV
A.2 IEC 60141-3: - External Gas- Pressure (Gas Compression) Cables and their Accessories for Alternating Voltages up to 275 kV
A.3 IEC 60141-4: - Oil-Impregnated Paper-Insulated High Pressure Oil- Filled Pipe-Type Cables and their Accessories for Altern...
Appendix B Design Features, Performance and Necessity for Performing Type Tests for Transition Joints
B.1 Back-to-Back Transition Joint with Two Insulators
B.2 Back-to-Back Transition Joint with One Insulator
B.3 Composite Type Transition Joint (Three-Core, Single Core)
B.4 Single-Core or Three-Core Type with Bushing
B.5 Methodology for Assessing Test Requirements
Appendix C List of Type and Prequalification Tests of Cable Systems
Appendix D Transition Joint Experience Data
Appendix E Terms of Reference for WG B1-24
References
9 Thermal Ratings of HV Cable Accessories
9.1 Summary
9.2 Introduction
9.3 Thermal Ratings of Accessories
9.3.1 Basic Considerations
9.3.2 Conclusions
9.4 Thermo-mechanical Ratings of Accessories
9.4.1 Basic Considerations
9.4.2 Conclusions
9.5 Systems Design Aspects
9.5.1 Thermal Ratings of Accessories
9.5.2 Thermo-mechanical Ratings of Accessories
9.6 Conclusions
Annexes
Annex 1. Thermal Calculations in HV and EHV Cables and Joints
Example 1: Dynamic Temperature Calculations in a 132 kV Cable and Joint
Conclusion
Example 2: Thermal Behavior of a 400 kV Joint during IEC Loading Cycles in Air
Introduction
Loading Cycle Temperature Profile Calculation
Conclusions
Annex 2. Overview of International Standards on Thermal Aspects of Accessories (as a Result of a Questionnaire under the Membe...
Annex 3. Guide to Aid Development Engineers for Testing the Thermal Properties of Joints
Introduction
Test Installation
Thermal Test
Test Results
Annex 4. Guide to Aid Design Engineers in the Correct Design of Systems: Thermal and Thermo-mechanical Aspects of Accessory Pe...
Introduction
References
Cable Systems: Way of Laying
Rigid Systems
Flexible Systems: Cable Horizontally Snaked or Vertically Waved
Semi-flexible Systems: Cable Constrained
10 Test Regimes for HV and EHV Cable Connectors
10.1 Background
10.1.1 Terms of Reference
10.1.2 Scope
10.1.3 Terminology
10.1.3.1 Connector (of Cables)
10.1.3.2 Through Connector
10.1.3.3 Terminal Lug
10.1.3.4 Barrel (of Terminal Lug, of Connector, etc.)
10.1.3.5 Reference Conductor
10.1.3.6 Compression Jointing
10.1.3.7 Mechanical Jointing
10.1.3.8 Median Connector
10.2 Cable Conductors
10.2.1 Basic Cable Conductor Types and Sizes
10.2.2 Materials for Cable Conductors
10.2.3 Fillers (Compounds, Yarns, Cloth, Powder, )
10.2.4 Construction of Cable Conductors
10.2.4.1 Insulated Strands and Sectors
10.2.4.2 Influence of Cable Construction on Design and Dimensions of Connector
10.3 Connectors for HV/EHV Cables
10.3.1 Basic Theory of Current Carrying Cable-Connections
10.3.1.1 Aging of Electrical Connections
10.3.1.2 Comparison of Material Properties
10.3.2 Connector Construction and Types for HV and EHV Extruded Cables
10.3.2.1 Compression Type Connectors
10.3.2.1.1 Compression Connector Design
10.3.2.1.2 Crimping Tools
10.3.2.2 Mechanical Connectors (Shear-Bolt)
10.3.2.3 MIG and TIG Weld Connectors
10.3.2.3.1 MIG Welded Connector for HV Joints
10.3.2.3.2 MIG Welded Connectors for HV Terminations
10.3.2.4 Exothermic Welded Connections
10.3.2.5 Copper Brazing
10.3.2.6 Clamp Connectors
10.3.2.7 Creuset Connector
10.3.2.8 Grounding Cable Connectors
10.3.3 Diagnostics for Cable Connector Condition Assessment
10.4 Cable Connectors in Accessories
10.4.1 General
10.4.2 Mechanical Loads
10.4.3 Environment
10.4.4 Cable Connectors in Joints
10.4.4.1 General
10.4.4.2 Thermal Rating of the Joint
10.4.5 Cable Connectors in Outdoor Terminations
10.4.6 Cable Connectors in Equipment Type Terminations
10.4.7 Connections to the Cable Connectors
10.4.7.1 General
10.4.7.2 Outdoor Terminations
10.4.7.3 Equipment Type Terminations (GIS and Oil Immersed)
10.5 Installation of Connectors
10.5.1 Installation Instruction Manual
10.5.2 Cable Conductor Preparation
10.5.3 Mechanical Connectors
10.5.4 Crimp Connector
10.5.5 Exothermic Welding Connector
10.5.6 MIG or TIG Welding Connector
10.6 Experience
10.6.1 Utility Presentations at WG Meetings
10.6.1.1 USA
10.6.1.2 Germany
10.6.1.3 France
10.6.2 Worldwide Survey
10.7 Existing Test Methods, Requirements, and Assessment in Cable Connector Testing
10.7.1 Medium Voltage Connectors
10.7.1.1 IEC 61238-1-3 Requirements
10.7.2 Additional Tests on MV Connectors/Accessories
10.7.2.1 Additional Studies
10.7.2.1.1 Mechanical Tests on Connectors
10.7.2.1.2 Water Ingress in Joint
10.7.3 Existing Practice in Testing HV/EHV Connectors
10.7.3.1 Development Tests on HV/EHV Connectors
10.7.3.2 Type and Prequalification Tests for HV/EHV Cable Systems and Accessories
10.7.3.3 Work of CIGRE WG B1.06 Concerning Connectors
10.8 Test Regimes for Cable Connector/Conductor Combinations in HV AND EHV Applications
10.8.1 General
10.8.2 WG Recommendations for Testing Connectors for HV and EHV Cables
10.8.2.1 Development Tests for Conductor Sizes up to and Including 1200 mm2
10.8.2.2 Development Tests for Conductor Sizes Above 1200 mm2
10.8.3 Range of Applicability of Development Tests
10.8.3.1 Covered Range of Nominal Cross-Sectional Areas of Conductor
10.8.3.2 Covered Range Based on Cable Insulation Material: Extruded vs. Impregnated Paper
10.8.3.3 Covered Range of Conductor Designs: Round Stranded and Compacted
10.8.3.4 Covered Range of Conductor Designs: Conductors with Insulated Segments or Strands or with Water-Blocking Material and...
10.8.3.5 Covered Range of Conductor Designs: Segmented and Milliken Conductors
10.8.3.6 Covered Connection Applications: Through Connectors for the Joints for the Same and Different Size Cable Conductors
10.8.3.7 Covered Connection Applications: Through Connectors and Terminal Lug
10.8.3.8 Covered Modifications of Mechanical Connectors in HV and EHV Applications
10.8.3.9 Covered Short Circuit Current Withstand Capability
10.8.4 Test Loop for Heat Cycling and Temperature Stability Tests for Development Tests with Conductor Sizes Above 1200 mm2
10.8.5 Recommended Development Test Sequence with Conductor Sizes Above 1200 mm2
10.8.5.1 Prestress
10.8.5.2 Constant High-Current Temperature Stability Test
10.8.5.3 Heat Cycle Temperature Stability Test
10.8.5.4 Tensile Strength Test on (3) New Connectors
10.8.6 Test Methods
10.8.6.1 Tensile Load (Prestress) Test Method
10.8.6.2 Short Circuit Current Test Method
10.8.6.3 Constant High-Current Temperature Stability Test Method
10.8.6.4 Heat Cycle Temperature Stability Test Method
10.8.6.5 Tensile Strength Test Method
10.9 Conclusions
10.10 References
Terms of Reference
Comparison of IEC and IEEE Type Test Requirements for Extruded Cables and Accessories for Voltages up to 245 kV
Comparison of IEC and IEEE Type Test Requirements for Extruded Cables and Accessories for Voltages 245 kV and above
Background Behind Range of APPLICABility and Proposed Development Tests
11 Standard Design of a Common, Dry Type Plug-in Interface for GIS and Power Cables up to 145 kV
11.1 Background
11.2 Terms of Reference
11.3 Definitions and Units
11.3.1 Definitions
11.3.1.1 Cable-Termination (IEC 62271-209)
11.3.1.1.1 Fluid-Filled Cable-Termination (IEC 62271-209)
11.3.1.1.2 Dry-Type Cable-Termination (IEC 62271-209)
11.3.1.2 Plug-in Cable Termination (IEC 62271-209)
11.3.1.2.1 Locked Plug-in Type Cable Termination (TB 605/Chap. 7)
11.3.1.2.2 Plug-in, Plug-out Type Cable Termination (TB 605/Chap. 7)
11.3.1.2.3 Locking Plug-in, Plug-out Type Cable Termination (TB 605/Chap. 7)
11.3.1.3 Insulator Assembly (TB 605/Chap. 7)
11.3.1.4 Insulator (TB 605/Chap. 7)
11.3.1.5 Plug-in Connector of Insulator (TB 605/Chap. 7)
11.3.1.6 Plug-in Connector of Cable (TB 605/Chap. 7)
11.3.1.7 Main-Circuit End Terminal (IEC 62271-209 and Compliant with IEEE 1300)
11.3.1.8 Cable Connection Enclosure (IEC 62271-209 and Compliant with IEEE 1300)
11.3.1.9 Cable Connection Assembly (IEC 62271-209 and Compliant with IEEE 1300)
11.3.1.10 Cable System (IEC 62271-209)
11.3.1.11 Sectionalizing Insulation (IEC 60840-2019)
11.3.2 Units
11.3.2.1 Pressure
11.3.2.2 Rated Voltages (IEC 60840)
11.4 Criteria for Interface Selection
11.4.1 Number of Interfaces
11.4.2 Technical Considerations
11.4.3 Impact of Short Circuit Time Going to 40 kA 3 s
11.4.4 Interface Designs
11.5 Cable Library Dimensions State of the Art
11.5.1 Voltage Class 72.5 kV
11.5.2 Voltage Class 123 kV and 145 kV
11.6 Inner and Outer Cone Evaluation
11.6.1 General Evaluation of Inner and Outer Cone Technologies
11.6.2 Evaluation of Inner and Outer Cone Technologies per Voltage Class
11.6.2.1 Recommendation for the 72.5 kV Voltage Level
11.6.2.2 Recommendation for the 123 kV and 145 kV Voltage Levels
11.6.3 Evaluation of Conductor Locking Connector
11.6.4 Conclusion on Interface Technology
11.7 72.5 kV Insulator Design and Specification
11.7.1 Design
11.7.1.1 Geometrical Parameters Taken from EN 50673
11.7.1.2 Additional Geometrical Requirements
11.7.1.3 Dielectric Parameters
11.7.1.4 Mechanical Parameters
11.7.2 Type Tests and Routine Tests
11.7.2.1 Type Tests
11.7.2.2 Routine Tests
11.7.3 Examples of Implementation
11.8 123 kV and 145 kV Insulator Design and Specification
11.8.1 Design
11.8.1.1 Geometrical Parameters
11.8.1.1.1 Recommendations for the Outer Shape of the Insulator
11.8.1.2 Dielectric Parameters
11.8.1.3 Mechanical Parameters
11.8.2 Type Tests and Routine Tests
11.8.2.1 Type Tests
11.8.2.2 Routine Tests
11.8.3 Example of Implementation
11.9 Pressure Management
11.10 Risk Assessment
11.11 Common Insulator Design Credibility
11.11.1 72.5 kV Insulator
11.11.1.1 Service Experience with ``Outer Cone´´ Connections, All Types
11.11.1.2 Service Experience with F Type Cone (as Defined in EN 50673)
11.11.1.3 Type Testing According to IEC 60840 of Cable Systems with F-Cone Type Connectors
11.11.1.4 Examples of Installation
11.11.1.5 Electric Stress
11.11.1.6 Conclusion
11.11.2 145 kV Insulator
11.11.2.1 Dielectric Parameters
11.11.2.2 Connection
11.11.2.3 Conclusion
11.12 Qualification Process
11.13 Conclusion
General Evaluation of Inner and Outer Cone Technologies
Reference of Available Tests for Common Interface Evaluation
Routine Tests
Type Tests
Sample Tests
Prequalification Tests
Development Tests
Tests After Installation
Information on the Selection of 145 kV Interface Selection
Principles of Use of the Current Connection Areas of the Common Interface
Principle of use of the Current Transmission Above the Lock-in System Area
Principle of use of the Current Transmission Below the Lock-in System Area
Qualification Process Experts Views
References