  Due to the energy transition, today's electrical networks include synchronous
machines and inverter-based resources interfacing renewable energies such as
wind turbines, solar panels, and Battery Energy Storage Systems to the grid. In
such systems, interactions known as coupling modes or dynamic interactions,
between synchronous machines and inverter-based resources may arise. This paper
conducts a clear and exhaustive study on a proposed benchmark, in order to
analyze, quantify and classify these new types of modes. Detailed models
representing electromagnetic transient phenomena are developed and linearized,
then used for conducting modal analysis to fully characterize the small-signal
stability of the system. Also, a sensitivity analysis is presented to evaluate
the impact of key parameters on the detected modes of oscillation. Besides the
exhaustive classification of the possible coupling modes, the proposed
benchmark and methodology can be used to study any given power system in a
minimal order modeling. The case of a fully detailed power grid based on the
IEEE 39 bus system was studied as an illustrative example.
