Emergency Switching Control Strategy of Grid-Forming and Grid-Following for Centralized Photovoltaic

The establishment of photovoltaic power stations in areas with relatively rich light resources and the effective use of renewable energy can reduce the contradiction between energy supply and demand and environmental pollution. This paper takes the photovoltaic array power generation, energy storage battery, and load combined source load storage system as the research object. Aiming at the weak support ability of fault transient voltage when intermittent photovoltaic grid connection occurs, a fault model of source load storage system is established. When the 10.5kV AC bus fails, the output characteristics of the energy storage converter using grid following and grid construction control are analyzed in view of the problem of voltage drop at the short-circuit fault point. The emergency switching control strategy of grid-forming and grid-following is proposed to stabilize the load voltage and power. In case of short circuit fault of 0.38kV AC bus, emergency switching control and low-voltage ride through control strategy of photovoltaic converter are proposed. Ensure that photovoltaic and energy storage are not disconnected from the grid. Establish system model in PSCAD/EMTDC electromagnetic transient simulation software. Verify the effectiveness of the proposed network following emergency switching control strategy. The proposed emergency switching control method can stabilize the load voltage and power when a short circuit fault occurs in the system. The reliability of the source load storage system is improved.