Employing Cascaded H-bridge Inverter Technology for Connection of Photovoltaic Panels to the Grid

In this paper, the cascaded H-bridge (CHB) multilevel inverter is employed as a grid connected inverter. This kind of inverter has interesting features compared to conventional inverters, including better efficiency, lower THD, lower common mode current injection, and better waveform quality. Using a series connection of H-bridge cells in this topology, not only is the independent control of photovoltaic panels provided but also a stepwise voltage waveform can be synthesized at the total ac terminal voltage, leading to lower filter size and switching frequency. This topology processes the electric power in one stage and does not need any step-up voltage transformers for grid connection. The simulation and experimental results confirm the effectiveness of this topology for grid connection of photovoltaic panels.

Keywords:

Cascaded H-bridge Inverter , Distributed Generation , Grid Connection and Photovoltaics.