Cross-Seasonal Optimal Dispatch of a Wind–Photovoltaic Hybrid Pumped-Storage Multi-Energy Complementary System

A hybrid pumped-storage power station (hereinafter referred to as the “hybrid station”) is developed by installing reversible pump–turbine units between cascade reservoirs, providing both conventional hydropower regulation and cross-seasonal energy storage capability. However, existing studies have mainly focused on its short-term peak-shaving function, while the potential of cross-seasonal water resource allocation remains insufficiently explored. This paper develops a medium-to-long-term cross-seasonal optimal dispatch model considering the seasonal regulation characteristics of hybrid pumped-storage stations, with the objective of minimizing residual-load variance. Seasonal reservoir storage rate-of-change constraints are introduced to represent the operation mechanism of storing water during wet seasons and releasing water during dry seasons. A Variable-Phase Progressive Optimality Algorithm (VPPOA) is proposed to solve the model. Three operation modes, including no hybrid storage, hybrid daily regulation, and hybrid seasonal regulation, are established for comprehensive evaluation under different hydrological conditions, renewable outputs, load variations, and algorithm performances. The results show that the proposed model achieves an annual cross-seasonal energy transfer of 848.8 GWh. Compared with the no-hybrid-storage scheme, the hybrid seasonal regulation scheme reduces the residual-load variance by 77.3%, increases the wind–PV accommodation rate from 40.3% to 96.6%, and decreases the wet-season wind–PV curtailment rate from 38.8% to 3.9%. Compared with the hybrid daily regulation scheme, it further reduces the residual-load variance by 26.1%, improves the wind–PV accommodation rate by 9.2 percentage points, and increases dry-season supply reliability from 93.2% to 100%. Moreover, VPPOA outperforms GA, PSO, and conventional POA, achieving a lower residual-load variance of 2861.05 MW2. The results demonstrate that the cross-seasonal regulation capability of hybrid pumped-storage stations can effectively enhance renewable energy accommodation and power supply reliability, providing support for the flexible operation of new-type power systems.