Performance Investigation of a Grid-Connected PV System Utilizing a Novel Ćuk Converter and LCL Filter with Passive Damping Techniques

This paper presents the design, simulation, and performance analysis of an improved double-stage grid-connected photovoltaic (DS-GCPV) system featuring a modified Ćuk converter with a coupled-switched inductor cell. The proposed system aims to enhance energy conversion efficiency, reduce voltage ripples, and maintain power quality under varying irradiance conditions. The first stage employs an advanced Ćuk converter optimized for high step-up voltage gain while mitigating switching losses through the use of coupled inductors. The second stage consists of a three-phase inverter with an LCL filter, which incorporates different passive damping techniques to minimize THD. Simulation results validate the system’s robustness and adaptability, demonstrating an efficiency of up to 94% for the proposed converter compared to conventional Boost and Ćuk converters. The system maintains low THD (1.14%) and a near-unity power factor, ensuring compliance with grid standards. The study also evaluates the impact of different turns ratios on converter performance and explores the effectiveness of various damping configurations on the LCL filter. The proposed design proves to be a reliable solution for maximizing energy conversion efficiency and maintaining grid power quality in renewable energy applications.