A Single Phase Cascaded H Bridge PV Inverter's Harmonic Compensation Strategy in an Unbalanced Condition

The cascaded H-bridge (CHB) inverter offers a significant advantage in its straightforward modular design. In a recent study, a unified multilevel inverter incorporating a unique H-bridge component was proposed. This innovative topology has been further refined to include switching devices and DC-link voltage inputs, enabling the generation of a multitude of voltage steps. This advancement is specifically aimed at enhancing control over both active and reactive power for individual DC voltage sources within a photovoltaic module, ultimately improving power quality and system reliability. The study also presents an original control strategy and proportional pulse width modulation techniques tailored for CHB multilevel inverters in grid-connected systems, where each H-bridge module can deliver variable power levels.