Calculation of transients on transmission lines with sequential switching

Abstract

A computationally efficient method is described by which sequential pole closure may be taken into account when integral transforms are used for the calculation of switching phenomena. The method is used to illustrate the effects of switching-in resistors and trapped charges on the overvoltages resulting in a particular case of long-line energisation. IntroductionSome recent papers 1 >2>3 on the calculation of switching transients have employed integral-transform techniques as the basic tool to permit the representation of the frequency dependence of the line parameters. The object of the present note is to extend their scope by describing a computationally efficient method which is applicable when the. individual poles of the breakers close sequentially. The method is general, in that it can be used for any linear system with multiple inputs or for a system containing nonlinear elements capable of a piecewise linear approximation.The method is illustrated for the energisation of a long, open-circuited transmission line through a breaker complete with switching-in resistors, as shown in Fig. 1. The effect of initial charges trapped on the lines is also considered. 2Outline of the method Consider the closure of a switch S ]k at time r lk {\ < k < 3) in the network of Fig. 1, with E k the corresponding R11 line E 2