An adaptive Power Control of Photovoltaic Virtual Synchronous Generators

Generally, photovoltaic grid-connected systems based on maximum power point tracking (MPPT) control need to be configured with a certain energy storage device to enhance the ability to support the stable operation of the power grid, which will increase project investment and maintenance costs, and virtual synchronous machines provides a solution for photovoltaic power to connect to the grid by simulating inertia and damping. Therefore, a control strategy of two-stage PV virtual synchronous generator without energy storage is proposed. This method adds DC bus voltage control to the MPPT control method of traditional photovoltaic systems, achieving adaptive matching of photovoltaic power to the load with an improved VSG control, and avoiding the phenomenon of light abandonment. When the photovoltaic power is sufficient, the system adopts DC bus voltage control strategy. When the PV power is insufficient, the system adopts the MPPT control and realizes the DC voltage stability through VSG control. At the same time, the method can also realize the operation of the photovoltaic system in grid-connected and off-grid. The simulation results show that this method has good dynamic and stable performance, and provides certain inertia and damping support for PV grid connection without adding energy storage equipment.