Performance Evaluation of a PV-Based Multilevel Inverter with Improved THD and Efficiency

This work presents the design, simulation, and performance evaluation of a three-phase multilevel inverter (MLI) system integrated with photovoltaic (PV) technology for grid-connected applications. The proposed system consists of a photovoltaic array, a Maximum Power Point Tracking (MPPT) controller based on the Perturb and Observe (P&O) algorithm, a DC-DC boost converter for voltage regulation, and a cascaded H-bridge multilevel inverter equipped with an LC filter to reduce output distortions. The entire system is modeled and analyzed using MATLAB/Simulink. Simulation results reveal that the system delivers a peak power output of ۳۰۰۰ W, maintains a regulated DC bus voltage of ۸۰۰ V, and produces a stable three-phase AC output voltage of ۴۰۰ V (RMS). The proposed inverter topology effectively reduces the Total Harmonic Distortion (THD) of the output waveform to ۲.۸% by optimizing the switching strategy using sinusoidal pulse width modulation (SPWM), significantly outperforming the ۶.۵% THD observed in conventional two-level inverter systems. Additionally, the system achieves an improved conversion efficiency of ۹۶%, up from the typical ۹۲%, through effective MPPT operation and low-loss inverter design. These improvements ensure superior power quality and reliable grid synchronization. The study underscores the viability of multilevel inverters in enhancing the performance of PV systems and promoting the efficient utilization of renewable energy sources for grid integration.

کلیدواژه ها:

DC-DC Converter ، Grid integration ، Multilevel Inverter ، Photovoltaic System ، Three Phase System ، THD