THE LONGITUDINAL EMF IN A COMMUNICATIONS CABLE TAKING ITS PARAMETERS INTO ACCOUNT

The expressions derived in [1-5] are widely used to calculate the coef ficients of mutual and self-induction between the conductors of commun ications cables with ground return. When calculating the longitudinal emf in them it is assumed that the wires are insulated from ground ove r the whole length of the line. The coefficient of mutual induction an d the longitudinal emf are determined solely by the parameters of the surrounding medium. However, the results of measurements show, in the majority of cases, that there is a considerable difference between the results of calculations of the longitude emf in insulated and grounde d conductors, particularly in the latter. It is not only the surroundi ng medium but also the parameters of the circuits - the affecting and affected influences, which take part. In this paper we prove the neces sity to take into account the effect of the parameters of a grounded c onductor and the resultant longitudinal emf induced in this conductor and, consequently, the need to determine the coefficient of mutual ind uction taking the parameters of the grounded circuits into account.