An optimization approach to determining the power of active filters Lidiia I. Kovernikova, Ngoc H. Bui, Oleg N. Voitov and Ludmila V. Semenova E3S Web of Conf., 216 (2020) 01069 Published online: 14 December 2020 DOI: 10.1051/e3sconf/202021601069