Calculation of forces exerted on to the preformed helical fittings of transmission lines

Abstract The preformed fittings, as a crucial component of overhead lines, directly impact the safe and stable operation of the entire transmission line. In recent years, preformed fittings in ultra-high voltage transmission lines have frequently encountered issues such as strand separation, misalignment, and breakage, posing potential threats to the stability of the power grid. To comprehensively assess the performance of preformed fittings and enhance the accuracy of analysis, this paper first employs an explicit solution method for quasi-static analysis to thoroughly investigate the impact of different analysis time steps on system energy and solution outcomes. During this process, a monitoring mechanism for the ratio of kinetic energy to internal energy is specifically established to ensure the accuracy and reliability of the analysis results. Based on the aforementioned research, this paper further focuses on the contact pressure, deformation, and slippage between the preformed fittings and the conductors, conducting a detailed analysis. Through this study, it is expected to gain a deeper understanding of the mechanical behavior of preformed fittings during actual operation and provide a solid theoretical foundation for their optimized design.