Planning Method for Layered and Partitioned Integration of Wind-Solar Renewable Energy Clusters

Driven by achieving the target of carbon peak and carbon neutrality, such new energies as wind power and photovoltaic (abbr. PV) generation rapidly develop, and large-scale, clustered, partitioned and stratified grid connection become the key development direction. In allusion to power system power flow fluctuation and voltage excursion due to large-scale grid-connection of new energy, a layered and partitioned grid-connection planning method for wind and PV power station clusters was proposed. Considering the topology of power grid and the impedance of transmission lines, based on the graph theory the power grid was partitioned, and a multi-indices assessment system to connect new energy into power grid, in which the voltage excursion, power flow fluctuation and the indices of economic operation were included, was constructed. Taking the minimized curtailment of wind power and PV power as the objectives, a layered and partitioned grid-connection planning model for new energy was established. The established model was simplified by the second-order cone approximation method of AC power flow, thus each assessment index was solved, and combined with TOPSIS comprehensive evaluation method all feasible schemes were assessed to determine the optimal grid-connecting scheme. Finally, using IEEE 39-bus system as computing example, both effectiveness and practicability of the proposed planning method are verified.