Multi-objective optimal dispatch of pumped storage in renewable-dominated hydro-wind-PV regional power systems

With the accelerated global energy transition, the installed capacity of wind and photovoltaic (PV) power continues to increase, making renewable-dominated power systems increasingly prevalent. However, the variability, intermittency, and limited controllability of wind and PV generation pose significant challenges to the secure and stable operation of power systems. Pumped storage hydropower plants are widely regarded as effective flexibility resources, yet their coordinated operation with hydropower, wind, and PV generation has not been sufficiently quantified. Focusing on renewable-dominated power systems, this study develops a multi-objective PSHP dispatch framework under prescribed hydropower, wind power, PV generation, and load profiles. Typical scenarios are constructed for different hydrological periods and PV output conditions to capture long-term hydrological variability and intraday PV output patterns under varying weather conditions. System performance is evaluated in terms of total system energy supply, source-load matching, and equivalent carbon-reduction benefit. Pareto-frontier analysis is used to reveal trade-offs among the competing objectives, and objective-weighting methods are then applied to identify compromise operating strategies. A case study based on a large-scale hydro-wind-PV base in Northwest China demonstrates that the integration of pumped storage hydropower significantly improves overall system performance. Daily system energy supply increases by 13.77%–38.38%, source-load power deviations are reduced by up to 72.26%, and equivalent carbon-reduction benefit improves by 5.49%–26.53%. These results indicate that pumped storage hydropower provides effective regulation capability and offers a practical reference for optimizing the coordinated operation of hydropower, wind power, and PV generation in renewable-dominated power systems.