DC-AC inverter with perspective of common mode and wave-shaping

The use of photovoltaic panels for is becoming popular all over the world for producing electricity for grid connection via using transformer. Grid-connection of solar panel without using a transformer is being reported nowadays. Photovoltaic (PV) grid connected converter without transformer is associated with the problem of non-existent galvanic isolation as a result of transformer absence. The most prominent one issue is the development of common mode voltage leading to common-voltage leakage current. Hence the grid connected PV module of transformer-less panel, though improve power efficiency, suffers from the loss of power due to leakage current. The leakage current in between grid connection and PV panel develops through paths made up by the parasitic capacitances. Moreover, some topologies propose for omitting this abysmal common mode leakage current. This paper shows how low-pass filters of different order affect the wave-shape of the resulting output voltage in the presence of common mode leakage current in transformer-less topologies.