Symmetric Impedance Modeling of Power Controlled Grid Following Converters

The traditional impedance model three-phase grid following converter is asymmetric, it results the frequency coupling effects. Further more, it requires the impedance model of the converter to be represented by a second-order matrix, which makes the stability analysis more complicated. Therefore, based on strict mathematical proof, this paper proposes a modified instantaneous power calculation formula that makes the impedance model symmetrical while making power control accurate and simplifying the stability analysis. Finally, the effectiveness of the theoretical is verified by simulation results.