Low cost microcontroller-based inverter integrated in PV systems

This paper deals with a novel transformerless inverter topology having high efficiency, low leakage current and no zero crossing distortions are encountered. In fact, the proposed topology is based on the conventional full bridge topology with an extra AC bypass branch to short circuit the load when the zero voltage of the control is applied. In this way, the current returning from the filtering circuit finds its path through the extra branch during the freewheeling period and remains at the AC side. This would increase the efficiency and decrease the leakage current. The control strategy of the proposed topology is based on a low cost microcontroller interfaced to two drivers to step up the MOSFETs gate voltages. The proposed inverter and its control strategy were implemented and promising results were obtained.