Efficient Voltage Boosting and Leakage Current Suppression Multi-Input Multilevel Inverter Structure for Grid-Tied PV Systems

Multilevel inverters (MLIs) offer efficient and effective solutions for integrating different renewable energy systems (RESs) with different outputs and separate controllers; however, the integration of multi-input MLIs in photovoltaic (PV) applications remains challenging due to increased component count, high switching stress, limited voltage boosting capability, and leakage current issues. Therefore, this paper proposes an efficient multi-input MLI structure for grid-tied photovoltaic (PV) systems that exhibits voltage boosting and leakage current suppression. The proposed structure is based on the dual-source switched capacitors (QT3L-QSC5L) 15-Level MLI topology. The proposed (QT3L-QSC5L) MLI has fewer components, produces high-quality output waveforms, and achieves high efficiency. Additionally, A sinusoidal pulse-width modulation (SPWM)–based control scheme is employed to enable independent maximum power point tracking (MPPT) for each PV source while providing inherent voltage balancing of the switched capacitors. Furthermore, the proposed structure offers an alternative solution for leakage current suppression, using an insulation resistor to attenuate the leakage current component to an acceptable level. The verification of the control method and the leakage current attenuation is performed through detailed MATLAB/SIMULINK©simulations under a realistic irradiation profile. The experimental setup based on dSPACE (DS-1103) hardware controller further validates the simulation results.