Gas Insulated Transmission Lines (GIL)

Gas-insulated transmission lines (GIL) is an established high voltage technology used when environmental or structural considerations restrict the use of overhead transmission lines. With an overview on the technical, economical and environmental impact and power system implications of GIL, this guide provides a complete understanding of its physical design, features and advantages. The author illustrates how to evaluate when GIL would be the best solution during the planning sequence and how to apply GIL in the electricity power network. Other key features include: operation and maintenance requirements with information on repair processes, duration, and different monitoring systems enabling the achievement of reliable and safe operation; a wide variety of realized applications from across the world over the past 35 years, illustrating typical fields of application through descriptions of real projects that the author has worked on; and future application possibilities in a smart transmission network, used for solving power transmission problems. This is an essential reference for engineers involved in planning and executing bulk power transmission projects overground, in tunnels or buried. It offers a concise summary of all areas of the subject and is the perfect aid for utility power engineers, consulting engineers and manufacturers worldwide.

Gas-insulated transmission lines (GIL) is an established highvoltage technology used when environmental or structuralconsiderations restrict the use of overhead transmission lines.With an overview on the technical, economical and environmentalimpact and power system implications of GIL, this guide provides acomplete understanding of its physical design, features andadvantages. The author illustrates how to evaluate when GIL wouldbe the best solution during the planning sequence and how to applyGIL in the electricity power network.Other key features include:* operation and maintenance requirements with information onrepair processes, duration, and different monitoring systemsenabling the achievement of reliable and safe operation;* a wide variety of realized applications from across the worldover the past 35 years, illustrating typical fields of applicationthrough descriptions of real projects that the author has workedon; and* future application possibilities in a smart transmissionnetwork, used for solving power transmission problems.This is an essential reference for engineers involved inplanning and executing bulk power transmission projects overgroundin tunnels or buried. It offers a concise summary of all areas ofthe subject and is the perfect aid for utility power engineersconsulting engineers and manufacturers worldwide.

Foreword xiiiAcknowledgements xv1 Introduction 11.1 Changing Electric Power Supply 11.2 Advantages of GIL 42 History 72.1 Transmission Network Development 72.2 Historical Development of GIL 203 Technology 393.1 Gas Insulation 413.1.1 Free Gas Space 423.1.2 Insulators 423.1.3 Gas-Tight Enclosure 443.1.4 Insulating Gases 463.2 Basic Design 653.2.1 Overview 653.2.2 Dielectric Dimensioning 683.2.3 Thermal Dimensioning 683.2.4 Insulation Coordination 683.2.5 Electrical Optimization 693.2.6 Transmission Network Studies 693.2.7 Gas Pressure Dimensions 703.2.8 High-Voltage Design Tests 703.2.9 Current Rating Design 723.2.10 Short-Circuit Rating Design 733.2.11 Internal Arc Design 743.2.12 Electromagnetic Current Forces Design 763.2.13 Mechanical Design 763.2.14 Integrated Overvoltage Protection 773.2.15 Particles 783.2.16 Thermal Design 793.2.17 Seismic Design 863.3 Product Design 933.3.1 Technical Data 933.3.2 Conductor Pipe 953.3.3 Enclosure Pipe 953.3.4 Size of Gas Compartment 973.3.5 Insulators 983.3.6 Sliding Contacts 1003.3.7 Modular Design 1003.3.8 Overhead Line Connection 1033.3.9 Bending Radius 1033.3.10 Joint Technology for Conductor and Enclosure 1043.3.10.1 Flanged Joints 1053.3.11 Corrosion Protection 1123.3.12 On-Site Assembly Work 1163.3.13 Monitoring 1173.4 Quality Control and Diagnostic Tools 1233.4.1 Quality of Parts 1243.4.2 Quality of Processes 1243.4.3 Partial Discharge Detection 1253.4.4 High-Voltage Testing On-Site 1263.4.5 Conclusion of Quality Control 1303.5 Planning Issues 1313.5.1 Network Impact 1313.5.2 Reliability 1393.5.3 Grounding/Earthing 1413.5.4 Safety 1413.5.5 Environmental Limitations 1433.5.6 Electric Phase Angle Compensation 1453.5.7 Loadability and Capability Overload 1453.6 Specification Checklist 1493.7 Laying Options 1533.7.1 General 1533.7.2 Above-Ground Installation 1543.7.3 Trench-Laid 1593.7.4 Tunnel-Laid 1603.7.5 Directly Buried 1663.7.6 Directional Boring 1823.8 Long-Duration Testing 1833.8.1 General 1833.8.2 Tunnel Version 1843.8.3 Directly Buried Version 1973.8.4 Long-Duration Test Results 2153.9 Gas Handling 2173.9.1 General 2173.9.2 Gas Mixture Handling 2173.9.3 Conclusion 2193.10 Commissioning and On-Site Testing 2214 System and Network 2254.1 General 2254.2 Line Constants of GIL 2254.3 Transmission Losses 2284.4 Operational Aspects 2314.5 Ageing 2344.6 Internal Arc Fault 2354.7 Maintenance 2364.8 Repair 2374.9 Personnel Safety 2374.10 Insulation Coordination 2384.11 System Control 2475 Environmental Impact 2535.1 General 2535.2 Visual Impact 2535.3 Electromagnetic Fields 2545.4 Gas Handling 2675.5 Thermal Aspects 2675.6 Recycling 2685.7 Lifecycle Assessment 2695.8 CO2 Footprint 2696 Economic Aspects 2736.1 General 2736.2 Material Cost 2736.3 Assembly Cost 2756.4 Transmission Losses 2766.5 Cost Drivers 2777 Applications 2797.1 General 2797.2 Examples 2807.3 Future Application 3127.4 Case Studies 3148 Comparison of Transmission Systems 3238.1 General 3238.2 GIL Features 3238.3 Technical Comparison 3248.4 Site Comparison 3308.5 Soft Parameters 3328.6 Economics 3339 Power Transmission Pipeline 3359.1 Feasibility Study 3369.2 Offshore Wind Energy in Europe 3399.3 Under Sea Tunnel System 3399.4 Offshore and Onshore PTPTM Constructions 3449.5 Next-Generation Technology 3469.6 Offshore Environment 34610 Conclusion 349References 351Index 361