A New Common-Mode Transformerless Photovoltaic Inverter

Transformerless inverters are being widely used in grid-connected photovoltaic (PV) generation systems. Transformer elimination, in grid-connected PV systems, has many advantages. This not only reduces cost, size, and weight, but also increases the whole system efficiency. However, once the transformer is removed, there is no galvanic isolation between grid and PV array; as a consequence, leakage current appears due to parasitic capacitance to the ground, resulting in prohibitive electromagnetic interference and security issues.