Research on active power control method of photovoltaic inverter based on passive theory under weak gric

The high line impedance and load fluctuations of weak grid can easily lead to grid voltage fluctuations and other issues. In order to make the grid-connected PV inverter have strong robustness and improve the dynamic response speed, the active power control method of PV inverter based on passive theory is proposed. Firstly, the control strategy of the power outer loop is given, and the Euler-Lagrange model of the inverter is established. And then the passivity property of the inverter has been analyzed. Finally, the dynamic response performance of the Euler Lagrange control technology is analyzed for the change of grid impedance and the change of grid voltage. And compared with PI control, the simulation results show that the method used in this paper has strong robustness. And the simulation results show that the passive controller can be applied to the weak grid environment with large impedance and unstable voltage, and the transient performance and robustness is better than PI control.