Small signal analysis applied to a single phase inverter connected to stiff AC system using a novel improved power controller

This paper presents an improved controller for a single-phase inverter connected to stiff AC system, which is based on frequency and voltage droops. A new feedback loop is introduced to increase the system damping. The small signal analysis and root locus plots are presented in order to show the connections between the feedback loop gains and behavior of the system. Simulation results corresponding to the numerical solution of the nonlinear system equations are presented to validate the small signal analysis. A description of a laboratory prototype and the respective experimental results are also presented to confirm the theoretical analysis