Simplified Transmission Line Models for Use with Computer-Aided Circuit/System Analysis Programs
Author | : Jerry I. Lubell |
Publisher | : |
Total Pages | : 174 |
Release | : 1973 |
ISBN-10 | : OCLC:227683994 |
ISBN-13 | : |
Rating | : 4/5 (94 Downloads) |
Book excerpt: Two distinct but complimentary techniques for modeling multiconductor transmission lines for use with the SCEPTRE computer program are presented. The transmission line models developed can be modified for compatibility with other circuit/system transient analysis programs and are amenable to modification to include nuclear weapon effects. The general modeling approach has been to develop computationally efficient and accurate terminal models which can be arbitrarily loaded at the source and load ends and which can be used in conjunction with nonlinear electronic circuit models using either simplified or discrete modeling techniques. The two modeling techniques developed are the state space method and the orthonormal function method. For both cases, all required parameters can be determined from terminal measurements. The state space method is a new approach to modeling transmission lines using a lumped approximation. For the multiconductor case, the orthogonal characteristics of wave propagation are used to decouple the modes of propagation except at the source and load boundary conditions circuits. The concept of the orthonormal function method is to derive a set of transfer functions in the Laplace domain relating forward and backward traveling waves on the line to voltages and currents at the source and load ends of the line, approximate the transfer functions with Laguerre polynomials, and representing the resulting rational polynomials in the time domain with state variable differential equations. For the multiconductor case, the orthogonal characteristics of wave propagation are used to separate the modes, and the transfer functions for each mode are determined.