INVESTIGATION OF A DC-DC CONVERTER BASED ON THE SEPIC TOPOLOGY USING THE AVERAGING METHOD

<jats:p>Using the averaging method, the processes in a DC-DC converter based on the SEPIС topology were investigated taking into account its operating modes. Mathematical models were developed, and analytical expressions were derived for calculating the converter parameters under steady-state continuous and discontinuous conduction modes. In the continuous conduction mode, two sub-modes determined by the ratio of total inductor current to the converter load current were considered, namely, the complete and incomplete inductor supply sub-modes. Analytical expressions were obtained for calculating the average values and ripple amplitudes of currents and voltages in all reactive elements of the converter. The boundary values of the converter parameters corresponding to the transitions between all sub-modes over the switching range were calculated and determined. It was established that the boundaries between the conduction sub-modes of the SEPIC converter depend solely on the parameter associated with the inductances of the inductors and are independent of the parameters associated with the capacitances of converter capacitors. The analytical expressions obtained with account taken of these sub-modes make it possible to improve the accuracy of calculating the parameters of converter based on the SEPIC topology at the design stage for the development of efficient power supplies and other power supply systems for electrotechnological and electrotechnical equipment. The results of simulation of the converter processes confirmed the validity of the developed analytical relationships. References 17, Figures 5, Table 1.</jats:p>