Comparison of frequency control concepts in isolated power systems with diesel generators and fully rated wind energy converters
Isolated power systems are usually small remote electrical power systems facing a range of technical challenges. Without possessing primary conventional energy resources of their own and being often situated long distances away from countries exporting fossil fuels, isolated power systems depend on...
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Format: | Others |
Language: | en |
Published: |
2017
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Online Access: | https://tuprints.ulb.tu-darmstadt.de/6731/1/Dissertation_Georgia.Papaioannou.pdf Papaioannou, Georgia <http://tuprints.ulb.tu-darmstadt.de/view/person/Papaioannou=3AGeorgia=3A=3A.html> (2017): Comparison of frequency control concepts in isolated power systems with diesel generators and fully rated wind energy converters.Darmstadt, Technische Universität, [Ph.D. Thesis] |
Summary: | Isolated power systems are usually small remote electrical power systems facing a range of technical challenges. Without possessing primary conventional energy resources of their own and being often situated long distances away from countries exporting fossil fuels, isolated power systems depend on expensive imports of primary energy for ensuring power generation. Integration of renewable energy sources would therefore seem to be both a practical and financially beneficial solution.
Frequency stability is a crucial aspect for all electrical power systems. However, interconnected power systems have in comparison to isolated power systems the ability of maintaining frequency stable due to large conventional power plants and to power reserves, as well as mechanisms that prevent a system collapse in case of a sudden severe power loss. The isolated power systems mentioned in this thesis dispose usually an autonomous power station (APS) mostly comprised from diesel fired synchronous generators and some kind of renewable energy sources. Since this is the most usual case in this thesis, the challenge of ensuring frequency stability for this kind of IPSs is presented, analysed and further explored by proposing and comparing frequency control concepts improving dynamic system response.
Primary and secondary frequency control in isolated power systems takes place in a different way as in interconnected power systems. Existing frequency control concepts are presented and two of them are selected. Their relation to the two most common used speed governors for diesel fired synchronous generators are implemented and tuned as well. With reference to several dynamic simulation events like load steps and three - phase short circuits, these frequency control concepts are compared before and after tuning, so as to be able to propose a best practice for a network operator of isolated power systems generally.
Moreover, the integration of Renewable Energy Sources and especially of fully rated wind energy converters is further explored. The aim is to determine if the proposed frequency control concept presented and explored before the integration would have a further positive effect after the integration, or if a new frequency control concept should be considered.
At last, a real case study validates the selected frequency control concept. IPS of Lesbos in Hellas has been modelled in detail and according to real data provided from the Hellenic electricity distribution network operator. The generalisation of conclusions enables proposing a frequency control concept for isolated power systems operators improving frequency stability. |
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