VSG Multi-Machine Parallel Power Decoupling Strategy Based on Improved Virtual Impedance.

Under low-voltage microgrid conditions, when virtual synchronous generators (VSG) are connected in parallel with loads, there is power coupling between the output active and reactive power due to the resistive characteristic of the equivalent transmission impedance, and the output power suppression effect cannot be accurately distributed with poor current circulation, which seriously affects the steady-state performance of the system; Secondly, the line impedance of each inverter control system often does not match the capacity ratio, making the traditional virtual impedance decoupling strategy somewhat limited. The paper proposes a power decoupling strategy based on improved virtual impedance to address this problem by using a fuzzy algorithm to monitor the VSG power angle to adjust the virtual impedance in real time and still meet the requirements of VSG parallel operation power equalization and circulating current suppression during sudden load changes. Finally, a VSG simulation model is constructed in MATLAB/Simulink to verify the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]