Ripple of a DC/DC converter based on SEPIC topology

Mathematical models serve as the basis for unified methods for the calculation and designing of radio-electronic devices. The developed limiting continuous mathematical model of a DC/DC converter, built using SEPIC topology, allows to determine the range of changes in currents flowing through the inductor windings and voltages on the capacitor plates, as well as to determine their maximum and minimum values for various converter parameters, such as switching frequency of the power switch, fill factor, element ratings, etc. The research results have shown that the phase coordinates of the mathematical model tend to the real values of currents and voltages of the converter when the switching frequency of the power switch is more than 200 kHz. Correspondence is established between the calculated values of the pulsation ranges and the results obtained during modelling (with changes in the filling factor and switching frequency of the power switch).