| 1. |
- Vieira Turnell, Alice, et al.
(författare)
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Risk and economic analysis of utilizing dynamic thermal rated transformer for wind farm connection
- 2018
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Ingår i: 2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018 - Proceedings. - : IEEE conference proceedings.
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 2. |
- Zarei, Tahereh, et al.
(författare)
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Reliability Considerations and Economic Benefits of Dynamic Transformer Rating for Wind Energy Integration
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 3. |
- Zarei, Tahereh, et al.
(författare)
-
Reliability considerations and economic benefits of dynamic transformer rating for wind energy integration
- 2019
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Ingår i: International Journal of Electrical Power & Energy Systems. - : Elsevier BV. - 0142-0615 .- 1879-3517. ; 106, s. 598-606
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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