A State Equation Model of a Single-Phase Grid-Connected Inverter Using a Droop Control Scheme With Extra Phase Shift Control Action

This paper presents a state equation model of a single-phase pulsewidth modulation inverter connected to the grid, using frequency-active power and voltage-reactive power droops, including an extra phase shift loop. The influence of the control parameters on the system's behavior can be studied using the proposed state equation model, which was obtained from the small-signal analysis. The model's results are compared with numerical simulations of the nonlinear system to verify their accuracy. Comparisons are also made with experimental data reported in the literature.