A Hybrid Bidirectional DC-DC Converter Based on a SEPIC/Zeta Converter with a Modified Switched Capacitor Cell

This paper presents the theoretical analysis and numerical simulation results of a bidirectional dc-dc converter formed by the integration of a SEPIC/Zeta PWM converter and a modified switched capacitor cell. The converter is suitable for connecting a battery energy storage system in a dc microgrid or in renewable energy solutions with storage. Due to the switched capacitor cell concept, the voltage stress on semiconductors is reduced, when it is compared with the conventional SEPIC/Zeta converter. Moreover, due to the input or output current source characteristic, the converter presents the advantage of charging/discharging the battery energy storage system with low-ripple currents. The paper presents numerical simulation results from a converter designed with the following design specifications: 240 V of input voltage, 400 V of output voltage, 1000 W rated power and 50 kHz switching frequency.