System dynamic behaviour challenges: operating experience and future trends

System dynamic response and related phenomena drastically changed in last ten years; this is a consequence of different factors: the very fast development of inverter based generation, the increase of distributed resources, the gradual decarbonization of generation mix and, at last, the change of load behaviour both in amplitude and distribution. The paper explores the more pragmatic effects over the grid due to this fast evolution and the actions and challenges in charge of the System Operators with a detailed focus on Italian initiatives.