The use of grid-forming inverters for grid-connection of photovoltaic units is the key to stable operation of the new energy grid in desert and gobi. The conventional PV load-shedding operation is greatly affected by irradiance and inaccurate power retention. To solve these problems

a PV active standby control strategy based on grid-configuration inverter is proposed. Firstly

a PV grid-connected structure containing reference and backup arrays is designed. Secondly

based on the two-stage PV topology

an active backup control is introduced at the front stage DC/DC and a grid-forming control strategy is introduced at the back stage DC/AC to realize active participation of PV units in grid frequency regulation. The control strategy introduces a constant DC capacitor voltage control to maintain the DC voltage while enhancing the inertia characteristics of the PV unit.Finally

the PV small signal model of the grid-forming inverter is established

and the influence of DC capacitor value on the PV frequency response is analyzed through the root trajectory. The simulation results verify the correctness and feasibility of the proposed control strategy.