The aim of this thesis work is to analyse the dynamic modelling of the electrical system of a hybrid-electric propulsion aircraft. The European HERA project, which envisages the construction of a regional transport aircraft with hybrid-electric propulsion by mid-2030, serves as a reference for this project. For the modelling of the system, the AMESim Simcenter simulation software was used. In the first part of the work, an analysis was conducted of the state-of-the-art demonstrators and technologies currently available for hybrid-electric propulsion aircraft. Subsequently, an in-depth study of the electrical system architecture of the reference aircraft was conducted, a crucial step in the development of the models in Amesim.