Summary
Conversion of existing AC lines to DC operation is generally considered the most effective way of increasing the power capability of the lines, especially for stability-constrained AC lines. Conversion to DC includes several aspects such as DC insulator dimensioning, and DC corona and field effects. The brochure gives information on these aspects and provides methods for their calculation.
Table of content
Chapter 1. Introduction
1.1. AC uprating alternatives
1.2. DC conversion - possibilities and constraints
1.3. Potential advantages of DC in an AC system
1.4. Methodology for DC conversion
1.5. References
Chapter 2. AC to DC Conversion Opportunities
2.1. Point-to-point DC schemes
2.2. DC ties embedded into an AC system
2.3. HVDC grids
2.4. Segmentation of synchronous systems
2.5. Long HVAC lines with intermediate substations
2.6. References
Chapter 3. Conversion Configuration Options
3.1. Monopolar options
3.2. Bipole options
3.3. Tripole option
3.4. Double-circuit options
3.5. Asymmetrical voltage assignment
3.6. References
Chapter 4. Corona and Field Effects of Converted Lines
4.1. Introduction
4.2. A systematic approach to the assessment of the role of corona
4.3. Corona effects
4.4. Field effects
4.5. Summary of AC and DC corona and field effects
4.6. Hybrid AC/DC line configurations
4.7. Environmental design criteria for converted lines
4.8. Corona and field effects calculation and verification
4.9. References
Chapter 5. Insulation Coordination Aspects
5.1. DC service voltage withstand
5.2. Overvoltages
5.3. Insulation coordination for the neutral conductor
5.4. References
Chapter 6. Issues and Costs of Line Conversion
6.1. Line conversion issues
6.2. Identification of costs
6.3. Influence on external structures
6.4. References
Chapter 7. Case Studies
7.1. Prospective conversion of parallel 287 kV circuits to DC
7.2. Conversion of a single circuit 275 kV AC line to 270 / 500 kV DC
7.3. Effect of pole conductor surface gradient on power transfer capacity
7.4. Conversion of a double-circuit line to a hybrid line
7.5. References
Annex A. Mechanisms of Corona Generation
A.1. Basic processes
A.2. Corona inception and Peek’s law
A.3. References
Annex B. Calculation of Conductor Surface Voltage Gradients
B.1. Isolated DC line
B.2. Hybrid configurations
B.3. References
Annex C. Calculation of RI Levels
C.1. Isolated DC lines
C.2. Hybrid configurations
C.3. References
Annex D. Calculation of AN Levels
D.1. Isolated DC lines
D.2. Hybrid configurations
D.3. References
Annex E. Calculation of Corona Loss
E.1. Isolated DC lines
E.2. Hybrid configurations
E.3. References
Annex F. Electric Fields at Ground
F.1. Isolated DC lines
F.2. Hybrid configurations
F.3. References
Annex G. Monopolar Operation and Enhanced Shield Wire Corona
G.1. References
Additional informations
| Publication type | Technical Brochures |
|---|---|
| Reference | 583 |
| Publication year | |
| Publisher | CIGRE |
| ISBN | 978-2-85873-279-1 |
| Study committees | |
| Working groups | WG B2.41 |
| File size | 2 MB |
| Pages number | 103 |
| Price for non member | 200 € |
| Price for member | Free |
Authors
J. Lundquist, Convener (SE)
L.O. Barthold (US), A. Beutel (ZA), A.C. Britten (ZA), D.A. Douglass (US),J. Iglesias (ES), V. Jankov (CA), J.A. Jardini (BR), D. Muftic (ZA), S. Steevens (GE)
Contributors:
R. Adapa (US), E. Brocard (FR), R. Iravani (CA), R. Lake (NZ), D.I. Lee (KR), J.F. Nolasco (BR), T. Papazoglou (GR), G. Ruiz (ES), A. Singh (ZA), P. Stevenin (FR), A. Useros (ES)
Keywords
AC to DC conversion, HVDC transmission, power transfer capability, corona effects, insulation coordination, hybrid AC/DC lines, converter stations, monopole configurations, bipole configurations, conductor reconfiguration
