Planering av regionnätsdrift - Begränsning av subtransitering genom radialläggning av maskade ledningar
(2018) In CODEN:LUTEDX/TEIE EIEM01 20172Industrial Electrical Engineering and Automation
- Abstract
- In Sweden today we have an electric power system which is changing. In context of the set energy- and climate goals the use of the transmission grid has started to adjust with consequences for the underlying sub-transmission grid. The situation is special since these two grids are firmly interconnected to each other, but are run by different companies. E.ON who is the operator of the sub-transmission grid in southern Sweden, notice that their grid in many ways is affected in a negative way by this ongoing development. Among other things they have noticed that there is power transmitted in the sub-transmission grid instead of the transmission grid, so called sub-transits, which leads to unnecessary losses in their grid. The aim of this... (More)
- In Sweden today we have an electric power system which is changing. In context of the set energy- and climate goals the use of the transmission grid has started to adjust with consequences for the underlying sub-transmission grid. The situation is special since these two grids are firmly interconnected to each other, but are run by different companies. E.ON who is the operator of the sub-transmission grid in southern Sweden, notice that their grid in many ways is affected in a negative way by this ongoing development. Among other things they have noticed that there is power transmitted in the sub-transmission grid instead of the transmission grid, so called sub-transits, which leads to unnecessary losses in their grid. The aim of this project is to investigate verticalization of the sub-transmission grid as a method to limit the problems with the sub-transits, and has been performed together with the grid operator E.ON Energidistribution in Malmö.
The study has been limited to a study area of E.ONs grid in south eastern Sweden. The performed analysis consists of five analyses which treat how the following: load flow and losses, fault clearing, contingency, reliability and subscription to the transmission grid are affected by a verticalization. Historical data has also been mapped where it is possible to see a connection between external forces and sub-transits in the sub-transmission grid.
The results show that there is a significant potential for loss reduction with a positive economic effect for E.ON. Loss reduction up till 2 MSEK/year for one specific disconnection is considered within reach. The disconnection of power lines which have potential to reduce the most losses in the sub-transmission grid, are increasing the losses in the transmission grid. The overloads in the sub-transmission grid are affected to a very small extent. To supply the consumers in the south it is primarily the power lines in the west that increase their degree of load when the eastern paths are disconnected. This situation becomes apparent in an event of contingency. The fault clearing is fully operational when the grid is verticalized with existing relay settings. The reliability is unavoidably poorer when the redundancy falls away, if not new technology is introduced. It has been seen though that disturbance is very unusual. The influence on the subscriptions can both be positive or negative, for a better or worse economic situation as a result.
Finally this is a complex problem where it is difficult to raise any clear conclusions. There are dimensions of topographies that change over time and analyses which points on both advantages and disadvantages. The objective of this project is to visualize these advantages and disadvantages and to create a foundation for discussion between the distribution system operator and the transmission system operator. (Less) - Abstract (Swedish)
- I Sverige idag har vi ett elkraftsystem som befinner sig i förändring. Med utgångspunkt i de uppsatta energi- och klimatmålen har nyttjandet av stamnätet börjat förändras med följder för underliggande regionnät. Situationen är speciell då dessa två nät är hårt parallellkopplade till varandra, men drivs av olika företag. E.ON som regionnätsägare i södra Sverige märker av att i många avseenden drabbas deras nät negativt av denna pågående utveckling. Bland annat uppstår det situationer med effektöverföring i regionnätet istället för i stamnätet, så kallade subtransiteringar, vilka leder till onödiga förluster i deras nät. Detta arbete har som syfte att undersöka radialläggning av regionnätet som metod att begränsa problemen med... (More)
- I Sverige idag har vi ett elkraftsystem som befinner sig i förändring. Med utgångspunkt i de uppsatta energi- och klimatmålen har nyttjandet av stamnätet börjat förändras med följder för underliggande regionnät. Situationen är speciell då dessa två nät är hårt parallellkopplade till varandra, men drivs av olika företag. E.ON som regionnätsägare i södra Sverige märker av att i många avseenden drabbas deras nät negativt av denna pågående utveckling. Bland annat uppstår det situationer med effektöverföring i regionnätet istället för i stamnätet, så kallade subtransiteringar, vilka leder till onödiga förluster i deras nät. Detta arbete har som syfte att undersöka radialläggning av regionnätet som metod att begränsa problemen med subtransiteringar, och har utformats tillsammans med E.ON Energidistribution i Malmö.
Studien har begränsats till ett delområde av E.ONs regionnät i sydöstra Sverige.
Analyserna som utförts utgår från fem delanalyser som i turordning behandlar hur effektflöden och förluster, felbortkoppling, fellfallsituationer, tillförlitlighet och abonnemang påverkas genom att bryta upp maskor i nätet. Historisk driftdata har även kartlagts där det går att se samband mellan yttre påverkan och subtransiteringar i regionnätet.
Resultaten visar att det finns betydande potential till förlustreducering med positiv ekonomisk följd för E.ON. Förlustbesparingar på upp till 2 MSEK/år för frånkoppling av en specifik ledning ligger inom vad som är möjligt. De fall som verkar kunna bespara mest förluster i regionnätet, ökar dock förlusterna i stamnätet vid en radialläggning. Överbelastningarna i regionnätet påverkas i liten utsträckning. Belastningsgraden ökar främst i de västra delarna av nätet, som behöver ta på sig extra överföring för att tillgodose konsumenterna vidare söderut när de östra ledningarna frånkopplas. Denna situation blir särskilt tydlig vid felfall. Felbortkopplingen fungerar tillfredsställande även i ett uppmaskat läge med befintliga reläskyddsinställningar. Tillförlitligheten försämras oundvikligen när redundansen försvinner om inte ny teknik införs. Det har dock setts att driftstörningar är ytterst ovanliga. Påverkan på abonnemangen kan både vara negativ eller positiv med förbättrad eller försämrad ekonomi som följd.
Slutligen är detta ett komplext problem där det är svårt att ge entydiga slutsatser. Det finns dimensioner av en nättopologi som ändras över tid och analyser som pekar på både fördelar och nackdelar. Målet med arbetet är att åskådliggöra dessa fördelar och nackdelar samt skapa ett underlag för diskussion mellan region- och stamnätsägare. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8938806
- author
- Erkander, Mattias LU
- supervisor
- organization
- alternative title
- Subtransmission planning - Limitation of sub-transits through verticalization of meshed grids
- course
- EIEM01 20172
- year
- 2018
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- Subtransitering, Nätplanering, Förlustreducering, Ärvda nätverk, TSO/DSO
- publication/series
- CODEN:LUTEDX/TEIE
- report number
- 5401
- language
- Swedish
- id
- 8938806
- date added to LUP
- 2018-05-29 09:22:35
- date last changed
- 2018-05-29 09:22:35
@misc{8938806,
abstract = {{In Sweden today we have an electric power system which is changing. In context of the set energy- and climate goals the use of the transmission grid has started to adjust with consequences for the underlying sub-transmission grid. The situation is special since these two grids are firmly interconnected to each other, but are run by different companies. E.ON who is the operator of the sub-transmission grid in southern Sweden, notice that their grid in many ways is affected in a negative way by this ongoing development. Among other things they have noticed that there is power transmitted in the sub-transmission grid instead of the transmission grid, so called sub-transits, which leads to unnecessary losses in their grid. The aim of this project is to investigate verticalization of the sub-transmission grid as a method to limit the problems with the sub-transits, and has been performed together with the grid operator E.ON Energidistribution in Malmö.
The study has been limited to a study area of E.ONs grid in south eastern Sweden. The performed analysis consists of five analyses which treat how the following: load flow and losses, fault clearing, contingency, reliability and subscription to the transmission grid are affected by a verticalization. Historical data has also been mapped where it is possible to see a connection between external forces and sub-transits in the sub-transmission grid.
The results show that there is a significant potential for loss reduction with a positive economic effect for E.ON. Loss reduction up till 2 MSEK/year for one specific disconnection is considered within reach. The disconnection of power lines which have potential to reduce the most losses in the sub-transmission grid, are increasing the losses in the transmission grid. The overloads in the sub-transmission grid are affected to a very small extent. To supply the consumers in the south it is primarily the power lines in the west that increase their degree of load when the eastern paths are disconnected. This situation becomes apparent in an event of contingency. The fault clearing is fully operational when the grid is verticalized with existing relay settings. The reliability is unavoidably poorer when the redundancy falls away, if not new technology is introduced. It has been seen though that disturbance is very unusual. The influence on the subscriptions can both be positive or negative, for a better or worse economic situation as a result.
Finally this is a complex problem where it is difficult to raise any clear conclusions. There are dimensions of topographies that change over time and analyses which points on both advantages and disadvantages. The objective of this project is to visualize these advantages and disadvantages and to create a foundation for discussion between the distribution system operator and the transmission system operator.}},
author = {{Erkander, Mattias}},
language = {{swe}},
note = {{Student Paper}},
series = {{CODEN:LUTEDX/TEIE}},
title = {{Planering av regionnätsdrift - Begränsning av subtransitering genom radialläggning av maskade ledningar}},
year = {{2018}},
}