Progress in Signals and Telecommunication Engineering Aleksandar Vuchev, Nikolay Bankov, Angel Lichev 10 2 2021 https://www.dline.info/pste/fulltext/v10n2/pstev10n2_2.pdf DC converters are working with resonant frequency and we use the bidirectional series DC converter in this work. We have suggested a control method by providing control characteristics improvement and decrease of the losses of the circuit elements. Using the set of existing analysis, we have introduced the improvements of the converters.