The essential limiting factor of the power transmission line transfer capabilities is the maximal allowed temperature of the conductor that should not be exceeded to avoid excessive sags. A commonly used conservative approach is to limit transfer capability to the worst case scenarios, i.e. hot, sunny, windless days. Of course, system operators strive to raise the limit with more sophisticated models that take into account actual weather conditions or even weather forecasts. As a consequence, there has been substantial research done on Dynamic Thermal Rating (DTR) models in the last few decades. Based on accumulated knowledge the leading standards in the field published guidelines for thermal rating for operative use. However, the proposed models rely only on empirical relations for determination of the temperature gradient on the surface of the conductor that dictates the heat flux due to the advection. This heat flux is the most intense cooling mechanism in play, and also the most complex to model. In this project, we extend the discussion about advective cooling with a direct simulation of temperature and velocity fields near the conductor with the focus on the natural convection regime. The introduced model considers Joule heat generation and heat transport within the power line and its vicinity, fluid flow driven by buoyancy force, solar heating, and radiation. The solution procedure uses RBF-FD numerical method combined with Poisson disk sampling nodal positioning algorithm, both implemented in our in-house library Medusa.
Project plan: available here.
The project is funded by:
- ELES: transmitting energy, maintaining balance.
and has a total amount of 85 000 Euro.
- Jozef Stefan Institute is the leading Slovenian scientific research institute, covering a broad spectrum of basic and applied research. Hereinafter referred to as “JSI”.
- Elektroinštitut Milan Vidmar is the leading Slovenian engineering and scientific research organisation acting in the area of electric power engineering. Hereinafter referred to as “EIMV”.
- Andrej Souvent
- Miloš Maksić
- Vladimir Djurica
The following papers or conference papers were produced with financing from this project
- MAKSIĆ, Miloš, DJURICA, Vladimir, SLAK, Jure, SOUVENT, Andrej, DEPOLLI, Matjaž, KOSEC, Gregor, Cooling of overhead power lines due to the natural convection. International journal of electrical power & energy systems, in review, 2018.
- KOSEC, Gregor, SLAK, Jure. RBR-FD based dynamic thermal rating of overhead power lines. AFM 18, Twelfth International Conference on Advances in Fluid Mechanics, Southampton: WIT Press. 2018, vol. 120, pp. 255-262.
- KOSEC, Gregor, SLAK, Jure. Numerical simulation of overhead power line cooling in natural convection regime. V: ECT2018, The Tenth International Conference on Engineering Computational Technology 2018, 4-6 September 2018, Barcelona
- KOSEC, Gregor, SLAK, Jure. Numerical simulation of natural convection from a heated cylinder. V: LIU, Gui-Rong (ur.), TROVALUSCI, Patrizia (ur.). Proceedings of the International Conference on Computational Methods, ICCM2018, 6th - 10th August 2018, Rome, Italy