New Excitation System for Indoor Testing of Overhead Conductors

In the study of wind‐induced motion of conductors of overhead power transmission lines, an indoor test span measuring 30 m or more is normally used. The span is generally excited into motion by an electrodynamic‐type exciter connected at a span end. This connection increases the stiffness of the span at the point of connection, which will affect the dynamic characteristics of the test span. A more exact simulation of the indoor test‐conductor motion is essential. Simulation of test‐conductor motion using the principle of electrodynamic forces between parallel, long conductors is proposed. Indoor test‐span motion by this method is equivalent to steady crosswinds excitation in the field as distinguished from galloping conductors resulting from a combination of wind direction, velocity, moisture, and temperature. Consequently, the results of vibration experiments also will be more exact. The principle employed in the new excitation system, the methods of excitation in indoor spans using the principle, and the advantages of the new excitation system as compared to the presently employed system are discussed in this paper.