A Three-Port Converter by Merging Three-Level Dual-Boost With LLC for PV-Battery Systems

This paper presents a new three-port converter (TPC) topology optimized for photovoltaic-battery system integration. By integrating a three-level dual-boost converter with a full-bridge <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converter via switch sharing, the proposed TPC simplifies power conversion and enables soft-switching, resulting in a more compact, efficient and cost-effective design. The three-level configuration effectively manages fluctuations in battery discharge voltage, while the interleaved structure reduces ripple currents in the PV panel, enhancing system stability. A hybrid PWM-PFM control strategy enables independent and efficient power management across all ports. The design and performance of the TPC are validated through theoretical analysis and experimental results.