Improvement Method of Photovoltaic Grid-Connected Stability Based on Virtual Synchronous Generator Control

In this paper, a new approach based on virtual synchronous generator (VSG) technology is proposed to solve the voltage fluctuation problem caused by grid-connected PV. A hybrid grid-connected PV-storage system is integrated by optimising the VSG control strategy. It not only provides the necessary damping and inertia to the grid, but also improves the dynamic reactive power support. By comparing the effects of PV systems with different grid connected capacities and locations under four control methods, the significant impact of grid connected location and capacity on power quality is revealed. The study clearly shows that the VSG grid-connected control method in combination with photovoltaic storage is more advantageous in increasing the grid-connected node voltage and reducing the harmonic distortion rate of the grid-connected current. The experiments show that the proposed method can increase the voltage by 1.29% and reduce the harmonic distortion rate to 1.11% for the same capacity compared to the traditional network connection method. This study not only provides valuable theoretical guidance, but also a practical reference for the design and management of future distribution networks.