Precise Control of Grid-Connected Distributed Photovoltaic Based on Grid-Forming Smart Load

According to the voltage fluctuation and inertia deficiency caused by large-scale distributed photovoltaic grid connection, the traditional solution is to configure more energy storage or construct inverter controller, but which may result in high equipment cost and environmental pollution. Therefore, precise control is designed to coordinate the flexible resource and the proposed grid-forming smart load. Firstly, the grid-forming smart load is designed by taking advantage of distributed photovoltaic, energy storage, and adjustable load based on the working mechanism of electric spring. Next, the model of smart load is constructed by using the small-signal method to design the grid-forming control strategy, which can enhance the system inertia through the adjustable load. Furthermore, three distinct working modes based on real-time photovoltaic power output can be categorized to utilize the adjustable loads and energy storage, which may reduce the total capacity of energy storage system. Finally, the experiment cases can be designed by the opal-RT OP5600 simulator of IEEE39, which can test the feasibility of the proposed grid-forming smart load under different working conditions, and the advantage can be proved by comparing to using only energy storage regulation.