Parametric Robustness Analysis for Parallel Feedforward Compensation Based Active Damping of LCL Grid Connected Inverter

In this paper a Parallel Feedforward Compensation method is considered to actively damp the resonance of single phase grid interfaced inverter with LCL filter. In this method, a compensator is added with filter plant in parallel manners and sum of capacitor voltage and compensator output is feedback at reference input voltage. Further, the difference voltage signal is feed to proportional controller to complete the damping loop. A bandpass section (BPS) is used as a compensator in damping loop. This method is attractive owing to a simple and relatively easy design procedure for a compensator. The stability and robustness of PFC method is analyzed under compensator and LCL filter parameter variations through bode plot tool. A Proportional (PR) Controller is used to regulate injected grid. Finally, the robustness of PFC method is validated by MATLAB simulation results.