A Novel Three Phase Seventeen Level Inverter for Grid Tied PV Applications

Multilevel Inverters (MLIs) have gained significant attention due to their compact and efficient design, making them well-suited for applications such as solar photovoltaic (PV) systems and power grids. This study introduces a novel three-phase, seventeen-level MLI topology that utilizes a switched capacitor (SC) approach with a common ground configuration to achieve an eightfold increase in input voltage. The number of output levels is determined by the parallel combination of SC1, SC2, and SC3 cells. Designed specifically for low-voltage PV systems, this Inverter eliminates the need for a separate boost DC/DC converter. Additionally, it is capable of handling reactive power, regardless of whether the grid power factor is lagging or leading. A dedicated modulation strategy ensures that the switched capacitor voltages remain stable within acceptable ripple limits. To regulate power flow and maintain DC-link voltage balance, a closed-loop dq current control method is employed alongside DC-link voltage control. The performance of the proposed seventeen-level MLI is evaluated through MATLAB/Simulink simulations in a gridtied PV system. Simulation results depicted that the total harmonic distortion (THD) in the grid current remains below 5 %, meeting IEEE standards for power quality.