The emergence of Gallium Nitrure (GaN) large gap components from the power component family (Silicium, SiC) suggests previously unreachable application prospects. However, the introduction of such components in conversion systems implies a new approach to system design, thus making it possible to fully exploit the potential of these components. Thus, the TOPGAN project approach adopts an application-driven design approach, exploring different options to address key technical and scientific challenges. Ultimately, the aim is to explore and demonstrate the added value of EXAGAN components in systems that address applications of today and tomorrow. Thus, four applications will be dealt with in the project: a PFC converter for industrial and automotive applications, a high-power switching cell by matching components, a high-frequency LLC converter and a data center power supply, each of which will result in demonstrators or prototypes incorporating EXAGAN components. The project is the initial phase of the implementation of a structuring power electronics application cluster in Toulouse/Labège. The Region’s support through the GRAINE system will allow us to initiate this ambitious dynamic on this theme, which will bring the Toulouse and Grenobloi ecosystems closer together.