Modified multilevel buck–boost converter with equal voltage acrosseach capacitor: analysis and experimental investigations

Recently, the circuitry of Multilevel Buck‐Boost Converter (here, calledMBBC 1 ) is suggested in the literature to attain high invertingvoltage by increasing the output levels of the classical buck‐boost converter.However, the only circuitry is suggested and detail investigations are notprovided. The major drawbacks of MBBC 1 are the voltages across theload capacitors side are unequal and the input current is not continuous.Therefore, the MBBC 1 is not well suited to feed multilevel inverterwhere a stack of capacitors is required with equal voltage across eachcapacitor. A new modified MBBC called MBBC 2 is proposed to achievecontinuous input current and equal voltage across each capacitor. The circuitryof MBBC 1 and MBBC 2 configurations are analysed withnon‐idealities to investigate its effects on the voltage conversion ratio. TheContinuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM)boundary conditions and modes of operation for MBBC 1 andMBBC 2 configurations are presented. The procedure for basicsdesign and components selection is elaborated. Additionally, comparison ofMBBC 1 , MBBC 2 and recently proposed a non‐isolatedDC‐DC configuration is provided. The performances of MBBC 1 andMBBC 2 configurations are tested with simulation and experimentalwork, and obtained results consistently show a good agreement with thetheoretical approach..