Research on Pumped Storage Capacity Allocation of Cascade Hydro-Wind-Solar-Pumped Storage Hybrid System Considering Economy and Operational Stability

Under the background of "carbon peaking and carbon neutrality" and the high proportion of wind and solar resources connected to the power grid, how to maximize the use of water resources in the southwest region to achieve the absorption of wind-solar power and the stability of fluctuations has widely attracted attention. Therefore, this paper proposes a capacity configuration method for hybrid pumped storage stations with a cascade hydro-wind-solar-pumped storage complementary system, which takes into account construction economy and running stability. Firstly, the steady-state output models of cascade hydro-wind-photovoltaic-pumped storage power stations are established considering the prediction error. Secondly, considering the investment cost recovery of pumped storage, a hybrid pumped storage capacity configuration model is constructed, which aims to maximize the daily benefit of the complementary system and minimize the peak-valley difference of the remaining load. Finally, the scenario optimization method is adopted to reduce the influence brought by the uncertainty of runoff-wind-solar. Three cascade hydropower stations and planned wind-photovoltaic power stations downstream of a basin on a typical day are taken as an example. The result shows that the peak-valley difference of the hybrid system is reduced by 1326.86MW and 35.68% with an extremely small cost compared with the system without pumped storage, which can provide theoretical support for the capacity configuration of hybrid pumped storage.