Power coupling analysis of inverters based on relative gain method and decoupling control based on feedforward compensation

The output active and reactive power of inverter-interfaced distributed generator are coupling when the line is both resistive and inductive. In this paper, it first indicates the reasons and necessity of decoupling the output active and reactive power. Then according to the line transmission power expression it analyzes the power coupling based on the relative gain method and also presents the calculation method and meaning of the coupling degree. Then, a decoupling algorithm based on the feed-forward compensation is proposed. At last, a simulation example is designed and the three groups of PSCAD/EMTDC simulation diagrams show that the proposed feedforward compensation decoupling method has good decoupling performance.