VSG low voltage ride through control strategy based on flexible adjustment of power angle and current

This paper proposes a low voltage ride through control strategy for virtual synchronous generators（VSG） to address the issues of power angle instability and current exceeding limits during power grid faults, based on flexible adjustment of power angle and current. Firstly, by analyzing the VSG fault characteristics under voltage drop in the power grid, the control objective of low voltage ride through is clarified. Secondly, based on the reactive power support requirements of the inverter, the VSG reactive power command is quantitatively designed to provide reactive current support for the power grid. Next, based on the VSG power angle curve and the equal area rule,adjust the VSG active command to enhance power angle stability and achieve quantitative control of power angle.At the same time, dynamic virtual impedance is used to suppress the VSG current surge at the moment of power grid fault. Finally, the effectiveness of the proposed scheme were verified through MATLAB/Simulink simulation.