Control Strategy for Multi-Port Converters Without Electrolytic Capacitors to Mitigate Low-Frequency DC-Link Current Ripple Effects

Multi-port converters (MPCs) are increasingly used for their flexibility in control and high-power density. However, fluctuations and low-frequency ripples in photovoltaic (PV) and DC bus currents can compromise system stability and lead to a reduced power factor. Enhanced control techniques, load moving, demand peaking reducing, optimal power management, and improved incorporation of renewable energy sources may all be used to address these problems. In this paper, Firstly, a modified perturb & observe (MP&O) method combined with PI control is introduced for maximum power point tracking (MPPT) via controlling the duty ratio of the PV DC converter. Secondly, a new and straightforward d-q current management method is used for DC-Bus management in both PV power and the battery energy storage system"s (BESS) state of charge (SoC) using flowchart-based decision logic. This approach ensures cost-effective implementation of the DC?Bus controller due to its low sampling frequency. The proposed MP&O-PI methods reduced the frequency DC bus ripples, and PV fluctuation, showing better suppression ability and dynamic response speed. Finally, a comparative analysis of the proposed MP&O-PI approach with a known state-of-the-art technique demonstrates a system stability improvement, faster response, and improved energy efficiency, approving the efficiency of the proposed control framework.