Structure-preserving tangential interpolation for model reduction of port-Hamiltonian systems

Port-Hamiltonian systems result from port-based network modeling of physical systems and are an important example of passive state-space systems. In this paper, we develop a framework for model reduction of large-scale multi-input/multi-output port-Hamiltonian systems via tangential rational interpolation. The resulting reduced model is a rational (tangential) interpolant that retains the port-Hamiltonian structure; hence it remains passive. We introduce an H 2 -inspired algorithm for effective choice of interpolation points and tangent directions and present several numerical examples illustrating its effectiveness.