Reconsideration of Grid-Friendly Low-Order Filter Enabled by Parallel Converters

High-order filters, such as inductor-capacitor-inductor ( LCL) filter, have been popular in grid-tied power converters. Although featuring small size, LCL filters are not grid friendly due to inherent resonance, especially when a large number of converters parallel operation todays electric attain modularity, reliability, and redundancy advantages. Thus, this article reconsiders the low-order L filter eliminate resonance turn simplify control. It is found that by interleaving certain converters, will be sufficient meet harmonic limit requirements standards, while size can even smaller than filter. This further contributes cost reduction promising solution for grid-friendly