LCL-filter-based bi-directional converter for connectivity of microgrids involving sustainable energy sources

In this paper, the design and implementation of a three phase bi-directional LCL-filter-based AC/DC converter is presented. The developed controlled converter is used for connectivity between DC distribution systems and the main utility grid. The performance of the developed converter will be compared with that of an L-filter based converter in terms of voltage regulation, control robustness, efficiency, harmonics and physical properties. Results show that, replacing the L-filter with an LCL filter increases the average efficiency of the converter mainly due to the reduction of the size of the inductors and their internal resistance. Also, the THD decreases significantly by using LCL filters. The obtained results verify the validity and applicability of the developed converter.