A Review on Single-Phase Transformerless Inverter Topologies for PV Applications

This article focuses on single-phase grid-tied transformerless inverter topologies for photovoltaic (PV) systems. These single-phase grid-tied PV inverters are widely used to connect the low power, roof-top, and residential photovoltaic systems to the grid and these are in the distribution side of the power system network. In grid-tied PV systems normally a transformer is employed to provide galvanic isolation between the input side and the output side with voltage level transformation. However, if we use a transformer the weight or size of the whole system increases, which is to be installed at the distribution side which makes the whole system size bigger. So, for PV systems it is better to use an inverter topologies that is without transformer. However, extra care must be taken while designing the transformerless inverters to avoid safety hazards like leakage and ground fault currents which will be discussed in this article.