Two-Stage Planning Method for Capacity Planning and Site Selection of Grid-Forming Energy Storage Considering Voltage Support Capability

The inherent intermittency and uncertainty of renewable energy generation lead to a decline in system inertia and voltage support capability, posing severe challenges to the stable operation of the power grid. To accurately evaluate the system's voltage support strength, an improved multiple renewable energy stations short circuit ratio (MRSCR) calculation method that accounts for grid-forming energy storage (GFMES) is proposed in this paper, along with the establishment of a two-stage planning algorithm for GFMES capacity determination and site selection. Firstly, a capacity planning model based on multi-scenario probability is constructed for the first stage. With the minimization of total cost as the objective, this model comprehensively optimizes the GFMES capacity and its charge-discharge strategies. Secondly, a site selection optimization model is proposed for the second stage. Aiming to maximize the system's voltage support capability, this model rationally allocates the total GFMES capacity to each power grid bus. Simulation results based on the modified IEEE 33-bus system demonstrate that the proposed method significantly enhances both the system's voltage support capability and operational economy, providing technical references for GFMES planning in power grids with high penetration of renewable energy.