In modern power systems, the demand for increased transmission capacity, reduced losses, and improved reliability is becoming increasingly prominent. One of the key factors affecting the operational characteristics of overhead lines is the conductor temperature. Higher temperatures lead to increased electrical losses, mechanical deformations (greater sag), and can potentially reduce the safety margins of the grid.
This master's thesis presents a passive approach for reducing conductor temperature using an optical coating that combines high solar reflectivity and high infrared emissivity. The theoretical part describes the fundamental principles of thermal radiation, blackbody properties, and spectrally selective coatings, supported by relevant mathematical models.
The experimental section includes laboratory measurements of the optical properties of the coating as well as a field test (polygon test) conducted under real operating conditions. The measurement results demonstrated a conductor temperature reduction of up to 15 °C during summer conditions, leading to reduced sag and potentially increased transmission capacity. Based on the field test data, a thermal model of the line was developed, which also enabled a simulation of potential annual performance and an economic analysis. This analysis indicates that the application of the coating would be most justified on heavily loaded lines or in combination with dynamic line rating (DLR) technology.
It can be concluded that the presented optical coating represents a promising solution for improving the efficiency and reliability of overhead power lines, despite currently high implementation costs. Further research and optimization of the formulation could enable broader and economically justified use in the future.
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