LLCL Filter Design for Grid Connected Inverters; a Detailed Performance Analysis

Currents injected into grid need to have a total harmonic distortion below 5% in grid connected inverters. to this aim, output filters are employed. for these filters, design conditions other than total harmonic distortion for voltage drop over the filter and reactive power consumption of the filter have to be also fulfilled. in literature, some filter schemes have been proposed to satisfy these conditions. in this study, the most important filter types are handled and a performance analysis between l, lcl and llcl filter was implemented. consequently, it is concluded that llcl filter has higher performance and lower cost, on the condition that some risky points are considered.