High-Gain Observer in Fuel Cell and Cascaded DC-DC Boost Converter System Soukaina Nady, Hassan El Fadil, Abdellah Lassioui, Yassine El Asri and Anwar Hasni E3S Web Conf., 601 (2025) 00062 Published online: 16 January 2025 DOI: 10.1051/e3sconf/202560100062