Dispatch optimization study of hybrid pumped storage-wind-photovoltaic system considering seasonal factors

The rapid growth and variability of wind and photovoltaic power generation have increased the reliance on hydroelectricity for regulation. A hybrid pumped storage hydropower-wind-photovoltaic system can help manage these fluctuations, but seasonal water flow changes at hydropower plants pose challenges. This study proposes a model for scheduling the hybrid system across seasons, optimizing capacity, water pumping, and power generation to reduce costs. The Wujiang River Hydropower Station in Guizhou, China, serves as the case study. The Results shows that: (1) 35 % increase in water storage at the second-stage hydropower station during the high-water period enables an additional 300 million kWh of power generation. (2)Water resource interaction between high-water and low-water periods reduces the likelihood of power supply loss by 10 %, while adding pumping stations cuts costs by 9.3 x 105 CNY. (3) A 10 % increase in feed-in tariffs raises costs by 9 %, and energy storage reduces waste by 155.6 MW during High-water periods. During peak hours (11:00-13:00, 6:00-10:00), both dry and abundant water storage devices must operate at full capacity, with surplus energy sold to the grid at other times.