Summary
The method of neutral earthing selected for a galvanic separated network is decisive for the supply reliability and safety of operation. It has a large impact on details in substation design. The report gives classification of methods and required equipment for fault protection, localisation as well as detailed equipment design and selection. Furthermore, the worldwide practise is reflected in the results of a worldwide survey.
Table of content
1. Definition
1.1. Introduction
1.2. Neutral Earthing Methods
1.3. Operational Priorities
1.4. Voltages
1.5. Sorting of Methods Referred to Operation
2. Reasons for Neutral Treatment
3. Fundamentals of Neutral Treatment Methods
3.1. Isolated Neutral
3.2. High Resistance Neutral Earthing
3.3. Resonant Earthing
3.4. Low Impedance Neutral Earthing
4. Augmented Neutral Treatment Methods
4.1. Isolated Neutral
4.2. Resonant Earthing
5. Protection
5.1. Earth Faults – General
5.2. Earth Fault Detection Options
5.3. Earth Fault Localization
5.4. System-Wide Protection
6. Equipment Details
6.1. Neutral Point Access
6.2. Arc Suppression Coil
6.3. Surge Arrestor
7. Safety Aspects
7.1. Conductor Sizing
7.2. Managing the Potential Rise
7.3. Interference with Metallic Structures
7.4. Operational Aspects
7.5. Vegetation Ignition Risk
8. Measuring Equipment
8.1. Measuring Schemes for Protection Functions
8.2. Measurement Accuracy
9. Staged Earth Fault Tests
9.1. Types of Fault Impedances
9.2. Examples of Tests in Resonant Earth Networks
9.3. Example of Test in a Network with Low Impedance Neutral Earthing
10. Planning and Operation
10.1. Basic Considerations for Planning
10.2. Basic Considerations for Operation
11. Advantages and Disadvantages of Various Neutral Earthing Methods
11.1. Isolated Neutral
11.2. High Resistance Neutral Earthing
11.3. Resonant Earthing
11.4. Low Impedance Neutral Earthing
11.5. Summary
12. Survey
12.1. Details of Questionnaire
12.2. Summary of Results
Additional informations
| Publication type | Technical Brochures |
|---|---|
| Reference | 997 |
| Publication year | |
| Publisher | CIGRE |
| ISBN | 978-2-85873-702-4 |
| Study committees | |
| Working groups | WG B3.52 |
| File size | 10 MB |
| Pages number | 89 |
| Price for non member | 170 € |
| Price for member | Free |
Authors
Theodor CONNOR, Convenor (DE), Tony YIP, Secretary (UK)
Hugh BORLAND (IE), Gert MADONSELA (ZA), Bill CARMAN (AU), Espen MASVIK (NO), Bruno CERESOLI (IT), Fazel MOHAMMADI (CA), Gernot DRUML (AT), Mark OSBORNE (UK), Christian EHLERT (DE), Bingyin XU (CN), Lothar FICKERT (AT), Kristine VALENTINSEN (NO)
Keywords
Neutral Earthing Methods, Physical Differences, Safety Aspects, Earthing Requirements, Equipment Selection, Protection Requirements, Staged Earth Fault Tests, Analysis of Questionnaire, Operational Challenges, Future Development
