Study on the influence of distributed photovoltaic access grid on voltage quality based on virtual synchronous control strategy

In recent years, with the continuous improvement of the grid-connected scale and installed capacity of distributed photovoltaic, especially for grid-connected local photovoltaic power generation in rural areas, mountainous areas and tidal flats, vicious voltage quality problems such as voltage increase in load station area have become increasingly prominent. This paper proposes photovoltaic grid-connected converters based on virtual synchronous control as the object. By establishing the sequence impedance model of PV grid-connected converters in the maximum power point tracking mode, the generation mechanism of voltage quality problems in the distribution network of PV access station area is deduced. Then, the impedance model of PV grid-connected converter based on virtual synchronous control strategy is established, and the simulation analysis shows that the control strategy can reduce the equivalent impedance of the grid in the station area, enhance the voltage support capability of the PV converter, and improve the voltage fluctuation and rise of the grid, providing a new idea for the distributed PV grid access area power generation and voltage quality problem management.