Optimal siting and sizing of pumped-storage power plants in a multi-HVDC-infeed regional power grid via AC security feedback

In regional power grids with multiple high-voltage direct-current (HVDC) infeeds, renewable-generation variability, variations in HVDC power transfers, and network constraints are strongly coupled, while planning solutions derived from DC power-flow models may not ensure AC operational feasibility. To address these issues, we propose an AC-security-feedback-based method for the siting and sizing of pumped-storage power plants. The proposed method integrates zonal source–load data with data from multiple HVDC infeeds to construct a joint scenario-feature set incorporating residual load and its ramping characteristics. Representative scenarios are then extracted through block-wise standardization, principal component analysis, and K-medoids clustering. Subsequently, a two-stage mixed-integer programming model is formulated by jointly considering candidate-site resource potential, engineering constraints, and grid-interconnection conditions. The model accounts for integer unit configurations, multi-scenario operation, operational constraints of conventional generating units, and reserve requirements. To overcome the inability of DC power flow to accurately represent active-power losses, reactive power, bus-voltage magnitudes, and branch apparent power, the resulting planning scheme is subjected to rigorous AC power-flow validation for every scenario and time period. The resulting security information is fed back into the planning model to iteratively refine the solution. Case-study results demonstrate that the proposed method preserves the computational efficiency of mixed-integer programming while effectively eliminating overloads on critical branches. All operating points satisfy the prescribed security constraints, thereby substantially improving the AC operational feasibility of the planning solution.