Analysis of DC-DC Buck Converter with Lossy Filter using Fractional-order Models

Power electronics is the processing of electrical power using electronic devices. Switching converters are the key elements. In a dc-dc converter, the dc input voltage is converted to a dc output voltage having a larger or smaller magnitude, possibly with opposite polarity. The buck converter reduces the dc voltage, using switches, inductors and capacitors. The integer-order model of buck converter used today, does not consider the inherent losses in the inductor and capacitor i.e. core loss in inductor and dielectric loss in capacitor. This paper deals with analysis of buck converter in the presence of lossy filter using fractional-order inductor and fractional-order capacitor. Fractional-order (FO) models of inductor and capacitor take into account the frequency dependent losses. By using the FO model of buck converter, it is possible to obtain more precise control of output voltage where more accuracy is required for the control.