Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Dynamic Rating of Power Lines and Transformers for Wind Energy Integration
KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering. (RCAM)ORCID iD: 0000-0002-4065-715X
2018 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Dynamic Rating (DR) is usually associated with unlocking the capacity of power lines and transformers using available information on weather conditions. Our studies show that Dynamic Rating is a broad concept that requires further study and development.

The capacity of the majority of power devices is highly dependent on the heat transfer properties of the materials which the devices are made of. To ensure correct power limits of the equipment, one must take into consideration not only the power load, but also ambient conditions, such as: temperature, wind speed, wind direction, solar irradiation, humidity, pressure, radiation into the atmosphere and magnetic losses.

Dynamic rating is created as an alternative to standard constant rating that is designed with reference to extreme weather and load conditions. Some areas are more likely than others to experience extreme weather conditions, which have a chance of occurring only a few days per year for short periods of time. Such a distribution of weather parameters gives an opportunity to embed existing material properties of the power equipment and achieve a better utilization of the grid.

The following thesis is divided into two simultaneous topics: Dynamic line rating and Dynamic transformer rating. The division is motivated by the importance of analysing the operation of the above-mentioned parts of the power network in greater detail. Power lines and transformers play a significant part in grid planning and have a potential to result in economic benefits when used with DR.

The main focus of the doctoral project "Dynamic rating of power lines and transformers for wind energy integration" is on exploring potential ways to connect power generated from wind to the grid with the help of dynamic rating technologies. Therefore, great focus of the work lies on the analysis of DR connection of variable energy sources such as wind farms.

The thesis presents the comparison of different line rating methods and proposes a new way of their classification. Evaluation of dynamic line rating application has shown the possibility to expand the power grid with additional capacity from wind power generation. Literature analysis and detailed evaluation of the conductor heat balance models have led to experimental evaluation of the convective cooling effect.

The dynamic transformer rating application has shown a possibility to decrease the size of the power transformer without shortcoming in component availability.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2018. , p. 54
Series
TRITA-EECS-AVL ; 2018:37
Keywords [en]
dynamic line rating, dynamic transformer rating, power transformers, heat balance, thermal modeling, wind power, wind energy integration, reliability analysis, risk analysis
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-226564ISBN: 978-91-7729-760-4 (print)OAI: oai:DiVA.org:kth-226564DiVA, id: diva2:1199581
Presentation
2018-05-09, Ivar Herlitz, Teknikringen 33, Stockholm, 10:00 (English)
Opponent
Supervisors
Projects
Dynamic Rating for Wind Power
Funder
StandUp for Wind
Note

QC 20180423

Available from: 2018-04-23 Created: 2018-04-20 Last updated: 2018-04-23Bibliographically approved
List of papers
1. Study of the Monitoring Systems for Dynamic Line Rating
Open this publication in new window or tab >>Study of the Monitoring Systems for Dynamic Line Rating
2017 (English)In: 8th International Conference on Applied Energy, ICAE 2016; Beijing; China; 8 October 2016 through 11 October 2016, Elsevier, 2017, Vol. 105, p. 2557-2562Conference paper, Published paper (Refereed)
Abstract [en]

Power system components usually have standard static ratings that determine the load constraints. Load constraints are designed for extreme conditions and are one of the reasons, why power systems do not use all of their potential transmission capacity. In the 21st century, efficiency and the cost of energy production and distribution have become a very popular topic, because the energy production and its transmission cost has a direct influence on sustainability. Dynamic Rating is a smart grid application, which allows using more of the system capacity by monitoring system conditions. This paper presents a literature review on the topic of Dynamic Rating. We focus on Dynamic Rating of overhead lines. Overhead lines are of great interest for Dynamic Rating applications, because of their high cost and high potential for further improvement. Different tools for analysis of real time data and ways of application of Dynamic Rating to the power system are taken into consideration.

Place, publisher, year, edition, pages
Elsevier, 2017
Series
Energy Procedia, ISSN 1876-6102 ; 105
Keywords
Dynamic rating, overhead line monitoring, ampacity
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Energy Technology; Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-207013 (URN)10.1016/j.egypro.2017.03.735 (DOI)000404967902103 ()2-s2.0-85020723416 (Scopus ID)
Conference
8th International Conference on Applied Energy, ICAE 2016, Beijing, China, 8 October 2016 through 11 October 2016
Projects
Dynamic Rating for Wind Power
Funder
Swedish Energy Agency, 76358
Note

QC 20170629

Available from: 2017-05-12 Created: 2017-05-12 Last updated: 2018-06-18Bibliographically approved
2. Risk analysis of wind farm connection to existing grids using dynamic line rating
Open this publication in new window or tab >>Risk analysis of wind farm connection to existing grids using dynamic line rating
2018 (English)In: 2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018 - Proceedings / [ed] Milorad Papic, IEEE conference proceedings, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Dynamic Line Rating (DLR) is a technology that allows extending capacity of existing power lines for transportation higher electrical power capacity from production site to the customer. Environmental conditions such as air temperature and wind speed have significant impact on the heat balance of the power line, therefore by monitoring the weather parameters one can dynamically vary the capacity of power line. Brief analysis of the wind speed and direction effects on the cooling of overhead lines and principles of wind power generation provide a background for the analysis of wind power connection to the existing power lines by means of Dynamic Line Rating.

This paper presents the case study of wind farm connection to the existing power line by application of DLR. Statistical weather data and information about system properties give an input parameters for the risk analysis of the dynamic rating application and highlight benefits of using DLR. The results show a potential to expand the transportation capacity of the line by injecting more wind power. Probabilistic analysis of the historical weather data and reliability analysis of the system show that line capacity can be expanded with more wind power without affecting availability of the connection.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-226539 (URN)10.1109/PMAPS.2018.8440517 (DOI)2-s2.0-85053155916 (Scopus ID)
Conference
2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018; Boise; United States; 24 June 2018 through 28 June 2018
Projects
Dynamic Rating for Wind Power
Note

QC 20180424

Available from: 2018-04-19 Created: 2018-04-19 Last updated: 2019-04-15Bibliographically approved
3. Reliability Considerations and Economic Benefits of Dynamic Transformer Rating for Wind Energy Integration
Open this publication in new window or tab >>Reliability Considerations and Economic Benefits of Dynamic Transformer Rating for Wind Energy Integration
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

An increasing share of renewable energy on the electricity market creates the need for economic and efficient production, operation and integration technologies, associated with the specific behavior of renewable energy sources (RES). Dynamic rating (DR) provides a possibility to apply improvements to the system both during planning and operation stages. The DR benefits are well described in various literature sources. However, DR is often focused on more efficient exploitation of power lines, not power transformers. Power transformers are costly equipment and their efficient usage and planning can have drastic effect on total costs.

Our analysis focuses on the dynamic transformer rating (DTR) for wind energy applications. The main objective is to study reliability effects of DTR from the component perspective. We utilize existing knowledge about transformer heat balance models from IEC and IEEE standards to obtain information on the loss of life (LOL) of the transformer under investigation and propose possible improvements for the system in question. The method can be employed for identifying the appropriate transformer size by taking into account ambient temperature and load variations and then overloading the transformer beyond nameplate ratings. The reliability of the proposed application is ensured by calculating the risk of overloading the transformer for each day of the year. A risk of overloading is quantified as LOL of the transformer. The risk is presented as a function of ambient temperature and duration of an overload. The final step consists of an economic analysis, which demonstrates economic benefits of DTR application.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-226563 (URN)
Projects
Dynamic Rating for Wind Power
Note

QC 20180424

Available from: 2018-04-20 Created: 2018-04-20 Last updated: 2018-05-23Bibliographically approved
4. Risk and economic analysis of utilizing dynamic thermal rated transformer for wind farm connection
Open this publication in new window or tab >>Risk and economic analysis of utilizing dynamic thermal rated transformer for wind farm connection
Show others...
2018 (English)In: 2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018 - Proceedings / [ed] Milorad Papic, IEEE conference proceedings, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Dynamic transformer rating (DTR) can be used to load power transformers above nameplate rating, while respecting contingency loading limits and ensuring an acceptable risk level. Purchase of power transformers is a major contributor for high costs of building new substations. Application of DTR allows to postpone the investment in new power transformers in old substations, thus DTR has a potential to become an economically beneficial technology. A quantitative risk and economic evaluation of DTR application is performed for a wind farm connected transformer and thus for a highly variable load scenario. The risks analyzed in this project are increased loss of insulation life and the risk of dielectric failure, based on the Arrhenius-Weibull model. A comparative net present value calculation has been performed to investigate the profitability of replacing a 19.4 MVA transformer with a 16 MVA dynamically rated transformer. The feasibility of DTR application is analyzed and a methodology is developed to support both transformer manufacturer and potential customers, such as distribution system operators, in the decision-making process of purchasing of dynamically rated transformer for wind energy applications.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-226544 (URN)10.1109/PMAPS.2018.8440479 (DOI)2-s2.0-85053145354 (Scopus ID)
Conference
2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018; Boise
Projects
Dynamic Rating for Wind Power
Note

QC 20180424

Available from: 2018-04-19 Created: 2018-04-19 Last updated: 2019-04-15Bibliographically approved

Open Access in DiVA

Dynamic Rating of Power Lines and Transformers for Wind Energy Integration(4887 kB)193 downloads
File information
File name FULLTEXT01.pdfFile size 4887 kBChecksum SHA-512
02224f438942ffb5b2f6ae43714d6f1bc9d78f4fd0ec37fcb3e207bcf08f367577ea4a02fa75b540860b6fe4491e2f5c514ff1983c9f7884c38480f1ab879333
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Morozovska, Kateryna
By organisation
Electromagnetic Engineering
Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 193 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 2997 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf