Improved calculation model for swing angle of suspension insulator string

In modern power systems, increasing faults of overhead transmission lines are caused by wind swing discharge especially in weather‐sensitive regions such as coastal hurricane‐prone areas. Since the vast majority of wind swing discharge accidents occur at the working voltage and existing models established for the suspension insulator wind swing discharge are not adequate to analyse all cases, an improved model under wind with arbitrary directions is proposed in this paper. Comprehensive factors are taken into consideration including exposure factor of wind pressure under different landforms and different elevations, wind pressure asymmetric factor, iced conductors, the coupling effect of conductors to insulators, the shielding wake flow effect of bundled conductor, the fluctuating wind amplification effect, mechanical oscillating of insulators, etc. IEEE model and design manual model are chosen as comparisons with the simulation results of ANSYS. Test results show that the improved model proposed in this paper coincides with ANSYS results better than the other two models almost in all the working conditions considering different spans and altitude differences. The results demonstrate that the improved model can make contribution to the economical and reasonable design of towers as well as early warning of wind swing discharge of suspension insulators.