Design of an Improved Gain Buck-Boost Converter for Photovoltaic Energy Harvesting Systems

This paper presents the design of a novel buck-boost converter that yields a high gain (voltage ratio) while maintaining its efficiency. The proposed topology is a two-switch buck-boost (TSBB) converter characterized by an improved gain in comparison to earlier designed conventional converters. This design is a combination of the single-ended primary-inductor converter (SEPIC) and the Cuk converter. This combination is achieved by reconfiguring the two existing diodes from both converters and sharing the SEPIC converter output inductor with the Cuk converter, thus harnessing the best properties of both converters. The gate switches are driven by synchronous gate drive pulse-width modulated signals. It also guarantees continuous input and output currents, making them suitable for high precision applications of renewable sources such as photovoltaic energy systems. Consequently, a simulation was performed to verify computational and design compatibility, yielding the desired result which is to step up an input voltage of 10 V to 12 V in boost mode at a duty cycle of 0.35 and step down an input voltage of 18 V to 12 V at the output during the buck mode at a duty cycle of 0.22.