Small Wind Energy Conversion System (SWECS), based on two back-to-back voltage source converters (VSC), with transformerless power injection into the utility grid, prove to be quite effective and reliable, but its efficiency and the compactness of its implementation can be improved. For this purpose, a modified topology, by introducing a floating-interleaving boost converter (FIBC), is proposed and evaluated. In this paper, theoretical and practical aspects related to the development of a FIBC dedicated to small wind power conversion, are presented. For a given rated values of power and voltage at the injection point into the grid, and a range of generator voltage, a FIBC converter is selected and sized, then realized and tested in stand alone operation and as element of a SWECS prototype. Experimental results confirm the suitability of the modified topology to achieve a very high efficiency of the wind energy conversion.