A reference model for modal approximations of linear transmission line dynamics

Abstract Transmission line dynamics is an important subject for the simulation of fluid power systems. In the case of moderate amplitudes, linear models are widely applied. While the frequency domain offers a very compact and straightforward description of the input- output behaviour, the implementation of transmission line models in standard simulation software using a linear, time-invariant, finite-dimensional state space system description poses an approximation problem that has been treated by a large number of authors in the fluid power literature. This paper presents the solution of the approximation problem in an optimal way and gives a set of reference data.