Optimal scheduling study of cascade hydropower stations to ensure ecological flow requirements-A case study of the Gorge Section of the Yongding River, China.

In order to maintain the ecological health of rivers and balance ecological and economic benefits, the study focuses on the Gorge Section of the Yongding River. The Lyon method was utilized to determine suitable ecological flow values. An optimized scheduling model for cascade hydropower stations was established to meet ecological flow requirements. Various scheduling scenarios were established to derive the optimized dispatching schemes for cascade hydropower stations. The results show that the appropriate natural ecological flow for the Gorge Section of the Yongding River, ranges from 4.05 to 9.86 m/s. Under Scenario 1 (outbound flow from Guanting Reservoir: 40.5 m/s, ecological flow: 4.50 m/s), Scenario 2 (40.5 m/s, 6.68 m/s), Scenario 3 (80.0 m/s, 4.50 m/s), and Scenario 4 (80.0 m/s, 6.68 m/s), the optimized scheduling schemes resulted in comprehensive system electricity generation of 10.4132 million kW.h, 9.1727 million kW.h, 18.6214 million kW.h, and 18.4660 million kW.h, respectively.