Switched Capacitor Nonisolated Step-Up DC–DC Converter With Low Voltage Stress of Devices and High Efficiency

With the increasing use of renewable energy sources today, high-voltage gain dc–dc converters have attracted the attention of researchers. This paper presents a nonisolated dc–dc converter with high voltage gain, designed for use in renewable energy sources, without restrictions on the switch’s duty cycle. The converter employs a switched capacitor technique to achieve higher voltage gain. Unlike some switched capacitor structures, the proposed converter does not exhibit high transient currents for the switched capacitors. The performance of the converter is analyzed in continuous conduction mode and discontinuous conduction mode under steady-state conditions, and the real voltage gain is calculated by incorporating parasitic elements, comparing it with recently introduced dc–dc converters. A comprehensive comparison with similar dc–dc converters is also conducted to demonstrate the high efficiency of the proposed converter. Other features of this converter include continuous input current with very low ripple, compact size and lightweight, easy control, small size of active and passive components, and low voltage stress on passive and active components. Small signal analysis and controller design for output voltage regulation have been carried out. To validate the mathematical analyses, a laboratory prototype rated at 20–228 V and 100 W has been constructed and evaluated.