Visual verification of line parameter data

Nearly all of the human effort in computing the parameters of overhead power transmission lines lies in the collection and entry of data. One must assemble data for conductors, tower designs and rights of way and then place the conductors on the towers and the towers in rights of way in a way that will result in the correct computation of self- and mutual-series impedances and shunt admittances. One can reasonably expect to find libraries of conductor data, or at least they are available in published references, but all the other data are specific to a given utility and must be developed and entered by the user. This article describes one solution that has been developed to address this problem of data expression with emphasis on some graphical aids that provide visual verification of the reasonableness of the data as entered.