Smart energy transition has significantly changed electric energy systems in many countries. Shares of wind power and solar electricity are already commonly prominent and still growing quickly. From power grid point of view, the change has culminated in replacing traditional synchronous generator-based production with power converter interfaced technology. Consequently, the general sensitivity of power grids to different disturbances has increased. The decrease of inertia is significant from frequency control point of view, but in addition, other issues related to abnormal voltage behaviour have also appeared. In order to support power grids in such situations, new technical solutions are required. Synthetic inertia is a topic covering different actions that aim to support power grids against such new disturbances by means of converter interfaced sources, usually battery energy storages. To understand the root causes of disturbances and requirements of synthetic inertia, dynamic modelling of electric energy system needs to be used. In this paper we build a dynamic model to reveal different disturbances in power grids and also the necessary engineering substance to understand these phenomena. From engineering education viewpoint this means that more emphasis should be put on understanding the physical and mathematical fundamentals. In this paper we show, what kind of knowledge becomes emphasized in understanding the fundamentals of supporting the power grid with synthetic inertia. We suggest that from engineering education point of view, the topic requires special attention.