The aim of this thesis is to investigate the asymmetrical operation of a 5-level resonant Buck converter in discontinuous conduction mode (DCM) under steady state conditions. The thesis contains a thorough description about the operation of the converter; a Simulink model with ideal elements that can be used to examine the operation and measure the results; and a detailed analysis, concluded by control diagrams. The converter has four outputs, which can provide equal or different voltage levels. It has several advantages, such as high efficiency and a wide range of possible output values.
The positive and negative channels are assumed to be symmetrical both in terms of passive elements and control. The following cases are examined: symmetrical loads and asymmetrical voltages, symmetrical loads and asymmetrical powers, symmetrical voltages and asymmetrical loads. The control strategies are characterized by these control parameters: capacitor voltage V_c and current of the inductor in the positive and negative channels: i_Lp and i_Ln. From these control paramters the switching angles α_p, α_cpp and α_epp (α_n, α_cnn and α_enn) are calculated. The results of the analysis are verified by simulation.
The results can be used for more advanced and complex DC-DC conversion, in order to fully exploit the possibilities in the rising popularity and affordability of renewable resources and DC mircogrids.