Advanced ROCOF protection of distribution systems
When islanding occurs, power supply from the main grid is interrupted which causes a problem when distributed generators continue to provide power into distributed networks. An islanding situation should be detected accurately soon after the island is formed. Because failure to trip the islanded dis...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
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2012
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| Online Access: | https://eprints.nottingham.ac.uk/14344/ |
| _version_ | 1848791936745340928 |
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| author | Liu, Bohan |
| author_facet | Liu, Bohan |
| author_sort | Liu, Bohan |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | When islanding occurs, power supply from the main grid is interrupted which causes a problem when distributed generators continue to provide power into distributed networks. An islanding situation should be detected accurately soon after the island is formed. Because failure to trip the islanded distributed resource can lead to a number of problems for the resource and the connected load. Although ROCOF islanding detection method is the most commonly employed anti-islanding protection technique, it provides fast detection and easily implementation. It is sensitive to the system disturbance. Therefore, the application of the ROCOF relay to detect system islanding has been limited.
This thesis proposes a solution to enhance the performance of the ROCOF relay by cooperation with rate of change of power or v2/p interlock function. During system load variation, the false operation of ROCOF relay can be blocked effectively. It is validated by applied in grid-connected synchronous generator, Doubly-fed Induction generator (both simulation and experiment) and microgrid. The principle of rate of change of power or v2/p interlock function are presented in this thesis. The new interlock function v2/p with ROCOF relays works well for different types of DGs within a short detection time without introducing perturbation into the system, which are the advantages over other active and hybrid islanding detection methods. The performances characteristics of ROCOF relays for DGs islanding detection (i.e. frequency measuring methods, measuring windows, generator inertia constant, relay settings and load power factor) are investigated. In addition, two other islanding detection methods (impedance measurement (active method) and the Total Harmonic Method) are applied to the grid-connected DFIG distributed system, the comparison and effectiveness of these two methods utilized in islanding and load changing conditions are also discussed. |
| first_indexed | 2025-11-14T18:36:26Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-14344 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T18:36:26Z |
| publishDate | 2012 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-143442025-02-28T11:30:13Z https://eprints.nottingham.ac.uk/14344/ Advanced ROCOF protection of distribution systems Liu, Bohan When islanding occurs, power supply from the main grid is interrupted which causes a problem when distributed generators continue to provide power into distributed networks. An islanding situation should be detected accurately soon after the island is formed. Because failure to trip the islanded distributed resource can lead to a number of problems for the resource and the connected load. Although ROCOF islanding detection method is the most commonly employed anti-islanding protection technique, it provides fast detection and easily implementation. It is sensitive to the system disturbance. Therefore, the application of the ROCOF relay to detect system islanding has been limited. This thesis proposes a solution to enhance the performance of the ROCOF relay by cooperation with rate of change of power or v2/p interlock function. During system load variation, the false operation of ROCOF relay can be blocked effectively. It is validated by applied in grid-connected synchronous generator, Doubly-fed Induction generator (both simulation and experiment) and microgrid. The principle of rate of change of power or v2/p interlock function are presented in this thesis. The new interlock function v2/p with ROCOF relays works well for different types of DGs within a short detection time without introducing perturbation into the system, which are the advantages over other active and hybrid islanding detection methods. The performances characteristics of ROCOF relays for DGs islanding detection (i.e. frequency measuring methods, measuring windows, generator inertia constant, relay settings and load power factor) are investigated. In addition, two other islanding detection methods (impedance measurement (active method) and the Total Harmonic Method) are applied to the grid-connected DFIG distributed system, the comparison and effectiveness of these two methods utilized in islanding and load changing conditions are also discussed. 2012-07-13 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/14344/1/582593.pdf Liu, Bohan (2012) Advanced ROCOF protection of distribution systems. PhD thesis, University of Nottingham. Electric power distribution systems Power supply interruption Islanding detection |
| spellingShingle | Electric power distribution systems Power supply interruption Islanding detection Liu, Bohan Advanced ROCOF protection of distribution systems |
| title | Advanced ROCOF protection of distribution systems |
| title_full | Advanced ROCOF protection of distribution systems |
| title_fullStr | Advanced ROCOF protection of distribution systems |
| title_full_unstemmed | Advanced ROCOF protection of distribution systems |
| title_short | Advanced ROCOF protection of distribution systems |
| title_sort | advanced rocof protection of distribution systems |
| topic | Electric power distribution systems Power supply interruption Islanding detection |
| url | https://eprints.nottingham.ac.uk/14344/ |