Dynamic Response of Iced Overhead Electric Transmission Lines Following Cable Rupture Shock and Induced Ice Shedding

摘要

Improved ice detachment failure criteria were implemented into the finite-element dynamic analysis of iced power transmission lines subjected to cable rupture shocks, which allows the study of the ice shedding effects that have been induced by the initial shocks. The modeling method is validated first experimentally by full-scale physical tests and then numerically by comparing with previous numerical methods. The case study shows that after considering the ice detachment failure subsequent to the initial rupture shock, the dynamic response of the iced line is significantly different from that obtained with previous iced line models that ignore the induced ice shedding effects. It shows that the previous equivalent density method tends to overestimate and the previous strain method tends to underestimate the maximum values and dynamic impact factors of cable tensions and insulator forces for the iced line following conductor breakage. It also shows that the cable-ground contact effect plays quite a different role in the bare cable model and iced line models. The proposed method can help improve the structure design of transmission lines and can also be used to study the dynamic response of lines subjected to other modes of line components failure, such as clamp slippage, insulator rupture, and tower deformation.