Design and Control of a High-Voltage-Gain Four-Port DC–DC Converter With Efficient Bidirectional Energy Storage for Renewable Energy Applications

Abstract

This paper introduces a novel four-port, non-isolated, multi-input single-output (MISO) DC-DC converter designed explicitly for integrating renewable energy. The proposed topology greatly enhances traditional multi-port converters by allowing two renewable sources and a bidirectional energy storage unit to connect simultaneously within a compact, integrated design. Its main advantages include a simplified circuit that reduces complexity and features common-grounded two-input ports for improved system compatibility. It achieves high voltage gain and continuous input current without requiring auxiliary voltage-boosting cells or complex magnetic structures. Additionally, it has a dedicated bidirectional port that enables efficient charging and discharging, thereby improving system resilience. A simple switching strategy ensures seamless transitions between operational modes. A comparative analysis shows that the proposed converter effectively addresses the main limitations of existing multi-port converter (MPC) topologies, including excessive voltage stress, high input current ripple, and control complexity. Included are detailed theoretical analysis and circuit modeling to demonstrate the new structure’s superior performance and reliability. Additionally, the small-signal model for each operating mode is developed to build the converter control system. Decoupling networks are used to establish independent closed-loop controllers due to interactions among converter control loops. To validate the feasibility and effectiveness of the proposed MPC, an experimental prototype with a nominal power of 150 W has been built. The findings emphasize the converter’s substantial potential for use in hybrid energy systems, establishing a new benchmark for high-efficiency, multi-port DC-DC conversion in energy platforms.