Advancing smart grid infrastructure by mitigating thermo-mechanical effects in optical fiber composite low voltage cable

Optical fiber composite low-voltage cable (OPLC) is increasingly used as a power cable in smart grid applications because they integrate electrical power transmission and optical communication in a single cable. However, the reliability of the communication signal is deeply affected by thermo-mechanical effects, which lead to signal attenuation and degraded performance. This study focuses on this issue by assessing the thermo-mechanical performance of OPLC by using finite element modeling and experimental validation. Using the finite element method, we simulated temperature and strain distributions under operational load and experimentally verified the results using Brillouin optical time-domain analysis (BOTDA) and optical attenuation measurements. Our findings demonstrate that thermoplastic elastomer (TPE) outperforms conventional polyethylene (PE) and cross-linked polyethylene (XLPE) as a heat-resistant layer for optical unit, limiting fiber temperature to 70.50 °C and reducing mechanical strain by 4.8% under rated current. The experimental data indicate that attenuation in optical fiber is mainly caused by strain, which accounts for 80.56% of the total signal loss, while the contribution from temperature is 16.03%. A critical strain level of 1200 με is identified, at which the attenuation reaches 0.15 dB/km for single-mode fiber. The study clarifies the relative roles of temperature and strain in attenuation, provides practical limits for material selection and structural design in smart grid cables to guide next-generation cable designs.