Universal DC-DC converter using SEPIC

This paper presents the application of fixed frequency (or indirect) Sliding Mode Control (SMC) to the DC-DC Single-Ended Primary Inductor Converter (SEPIC) which can operate in both step-up and step-down modes. Simulation and experimental studies are conducted. Two laboratory prototypes have been made: one with a switching frequency of 20kHz uses a DSP board which allows to validate the proposed control laws; another has a switching frequency of 500kHz where a FPGA is required. In this last case, only the output voltage is measured. A Kalman observer is proposed to estimate the state vector. Results are experimentally validated.