The flood resource utilization of cascade hydropower stations based on the multi-scenario water level drawdown method

In the dual context of global energy shortages and decarbonization, increasing the share of clean energy in the power supply is imperative. Hydropower, as a crucial component of renewable energy, often sees its significant potential for power generation during flood periods overlooked. This study aims to enhance the joint power generation of cascade hydropower stations under different typical flood scenarios. Firstly, a multi-scenario water level drawdown method is proposed, providing strong technical support for hydropower stations to utilize flood resources and generate more clean power. Then, typical flood scenarios are selected that take into account the relationship between the basin's flood characteristics and the critical flows specified in reservoir flood dispatch regulations. Further, a flood resource utilization scheduling framework is developed to investigate the joint power generation benefit of cascade hydropower stations adopting different credible forecast times under various operational periods. The main conclusions are as follows: (1) The multi-scenario water level drawdown method can timely lower the reservoir level to the flood control level. (2) Longer credible forecast times don’t always result in better performance, and the appropriate credible forecast time should be selected based on different inflow scenarios to maximize power generation. (3) Through the flood resource utilization scheduling framework, the joint power generation benefit of cascade hydropower stations has increased significantly for 7-1-1 (38.96*10⁴kW·h), 8-3-1 (145.18*10⁴kW·h) and 12-1-1 types flood (351.38*10⁴kW·h).