Impedance Modeling and Stability Analysis of Three-Phase Four-Leg Grid-Connected Inverter Considering Zero-Sequence

With the increasing applications of grid-connected voltage source converters, it is important to analyze impedance characteristic system implement stability analysis grid connection operation. Compared with three-phase three-wire system, an additional zero-sequence path exists in four-wire system. Therefore, necessary consider influence zero sequence when analyzing In this paper, model including positive-sequence, negative-sequence and four-leg inverter established. Through analysis, relationships between can be found which are decupled. Based on developed model, main factors affecting revealed. Then, consisting investigated, experimental results validate theoretical analysis.