New approach to integrate an LCL filter and a transformer for grid connected converters following a simple design procedure

Many grid connected power electronic systems need a dc/ac conversion stage. LCL topology is useful to filter harmonic content of the output inverter voltage, achieving high harmonic content attenuation. On the other hand, the use of a transformer provides galvanic isolation, and it adds and extra freedom degree to adjust the output voltage level. This work proposes a simple solution to integrate the LCL filter and the transformer in the same magnetic core. These three magnetic components can be independently designed following an easy design procedure, and with a good performance respect to the manufacturing tolerances.