Abstract: Under severe icing conditions，the iced sub-conductor may be connected by the ice bridge to form a connected ellipse iced conductor，resulting in the increase of windward area and aerodynamic shape deterioration of conductors． In order to study the aerodynamic force characteristics of the connected ellipse iced conductor ( with the ice bridge) and the separated ellipse iced conductor ( without the ice bridge) ，the high frequency force balance wind tunnel tests were conducted． Based on the test results，the effects of aerodynamic force characteristics of two ice accretion types on galloping stability and wind-induced swing response were analyzed． The results show that: ( 1) compared with the separated ellipse iced conductor condition，the lift force curve of the connected ellipse iced two-bundled conductor has a slower drop around peak，and the mean lift force coefficient is much larger in high wind attack angle cases; ( 2) near the wind attack angle of 170°，the mean torque coefficient of the separated ellipse iced conductor is larger than that of the connected ellipse iced two-bundled conductor; ( 3) the drag forces of conductors with the two iced types both satisfied the quasi-steady assumption; ( 4) for the vertical galloping，the separated ellipse iced conductor has worse stability，and for the torsional galloping，the connected ellipse iced conductor is more disadvantageous; ( 5 ) under the same wind velocity and transmission line condition，the wind-induced response of the connected ellipse iced conductor is larger than that of the separated ellipse iced conductor，leading to greater wind-induced swing accident risk．

Key words: transmission line, iced conductor, aerodynamic characteristic, galloping stability, wind-induced swing response