Input-Output Properties of the Power Grid’s Swing Dynamics: Dependence on Network Parameters

The design of wide-area controllers for the bulk power grid requires characterization of input-output channels in swing-dynamics models. However, the large variability in operating conditions in the modern grid makes the evaluation of channel transfer properties challenging. In this study, we examine how transfer functions in the classical swing dynamics model depend on network model parameters (the topology of line susceptances, generator inertias, dampings) and the channel location, focusing particularly on determining conditions under which the transfer function is guaranteed to be minimum phase or conversely nonminimum phase. In particular, graph-theoretic conditions as well as numerical bounds on network model parameters are obtained, that either preserve minimum-phase dynamics or yield nonminimumphase behaviors.