Wind tunnel test of the influence of an interphase spacer on the galloping control of iced eight-bundled conductors

To study the anti-galloping effect of interphase spacers with different kinds of arrangements on an iced transmission line, wind tunnel experiments using a full aeroelastic model are carried out in this work. Using similarity theory, the similarity criteria between the aeroelastic model and the prototype have been deduced. A triangular arrangement of three phases is considered, and the arrangements of iced eight-bundled conductors with and without the spacers are divided into six cases. In the experiments, laser sensors at different positions along the span of each phase are used to measure the variation of dynamic displacements with wind speed. Furthermore, galloping characteristics, such as the responses, frequencies, vibration modes, amplitudes and distance between two phases, are obtained for different wind speeds and arrangements. The obtained results show that interphase spacers have a certain inhibitory effect on the first symmetric mode and the first anti-symmetric mode galloping, but not all of the arrangements have a positive effect. The regularity of the variation with wind speed of the anti-galloping effect with interphase spacers is summarized. The galloping amplitude curves indicate that the amplitude is likely to be larger when a modal transformation occurs, in contrast to the results obtained without interphase spacers. The motion of the phase C located close to the diffusion section is different from those of the other two phases. Moreover, due to interphase spacers, the distance between the two phases is increased. The obtained conclusions can be used to predict the positions of interphase spacers and provide a fundamental tool for anti-galloping of eight-bundled conductors.