The Attenuation and Distortion of Travelling Waves on Overhead Power Transmission Systems at Voltages Below the Corona Limit

A solution due to Jacottet, of the problem of the distortion of a vertical-fronted voltage wave of infinite length as it travels along a simple line, is used as a basis for the development of formulae and curves for the attenuation and distortion of chopped waves, and of waves with vertical or finite fronts and exponential tails. These results are employed to show how to obtain limiting values for the original shape and amplitude, and distance travelled of a wave recorded at any point on a simple line, and also to calculate its behaviour at any other point. Using Bekku´s method of subdivision of waves, formulae and curves are developed to calculate the attenuation and distortion of waves on single- and three-phase power transmission systems for disturbances in any or all lines, and it is shown how phenomena observed in practice may be accounted for. The effect of earth wires is also considered. The results obtained are compared with oscillograms of artificially produced surges in three-phase power transmission lines, and excellent agreement is obtained.