A highly efficient method for calculating transmission line transients

A highly efficient method for digital calculation of transients on transmission lines with frequency-dependent effects is presented. The most time consuming part of calculating the transmission line transients in time-domain techniques such as traveling-wave methods is numerical evaluation of real-time convolution for including the frequency-dependent effects of the transmission lines. In the new method developed in the paper, a time response of a frequency-dependent parameter is simulated with linear curves. Then, the convolution in time-domain is evaluated by a sum of very few multiplications of the time response and a traveling-wave variable in which the effect of the frequency dependent parameter is to be included. Computation time required for the convolution is reduced to much less than one tenth, and the total computation time of a transient calculation is easily reduced by half compared with conventional methods for calculating transmission line transients.