Temperature rise characteristics of preformed helical fitting based on finite element method

Abstract Preformed helical fittings play an indispensable role in ensuring the safe and stable operation. Due to factors such as the material of the strands, environmental temperature, number of strands, and pitch, preformed helical fittings inevitably experience uneven heating during operation, which can cause localized softening of strands, leading to warping or even fracture. Therefore, studying the temperature rise characteristics of preformed helical fittings is crucial for ensuring the safety of power transmission lines. This paper derives the general parametric equations for preformed helical fittings used in three-dimensional modeling, and simplifies the contact conditions, establishing a three-dimensional multi-electrode simulation model to effectively simulate and quantify the contact between the strands and the conductor. Studying the temperature distribution of preformed helical fittings under various strand materials, environmental temperatures, number of strands, and pitches, it was found that the electrical conductivity is the primary factor influencing temperature rise characteristics and preformed helical fittings made of high-conductivity materials can effectively suppress temperature rise at contact points, while strand fracture may lead to increased temperatures at the rupture site, further exacerbating faults. This research provides valuable insights into the normal operation and maintenance of preformed helical fittings in power transmission lines.