Transient analysis of nonuniform lossy transmission lines with frequency dependent parameters

An s-domain method for transient analysis of lossy, frequency dependent non uniform transmission lines having parameters arbitrary varying with space i s presented. Nonuniform line is divided into adequate number of sections wh ich are then assumed uniform. The terminal equation for the nonuniform line is calculated by using the terminal equations of the uniform line sections . By using the boundary conditions, total response in s-domain is obtained. Fast inverse Laplace transform is used for frequency to time domain conver sion. In one of the examples, the step response of an open ended nonuniform line is obtained and the results are compared with those obtained by latti ce-diagram technique. The effect of number of sections is investigated and it is concluded that for sufficiently large number of sections, the results approach to the analytical solutions which can be obtained only for very s pecial nonuniform lines. In the second example, the method is applied for t he calculation of transmission tower lightning surge response. (C) 1999 Els evier Science S.A. All rights reserved.