Water storage operation of cascade reservoirs based on storage energy index

Optimizing the storage operation of cascade hydropower station at the end of flood season can improve the utilization efficiency of basin water resources.The traditional indicators of water fullness storing rate of the cascade reservoirs focus on the proportion of reservoir water, without considering the hydraulic and electric connection among cascade reservoirs, so the storage benefit of cascade reservoirs is not characterized.In this paper, we proposed an evaluation index of cascade reservoirs storage efficiency based on storage energy.With the goal of the maximum power generation and the maximum energy storage in water storage period, an optimal operation model was established, using the DPSA algorithm to optimize the reservoirs refill trajectories.A case study of the Qingjiang cascade reservoirs indicated that compared with the conventional regulation, the mean annual power generation of the optimized operation based on energy storage index increased by 3%.The optimized operation based on storage energy could give a more comprehensive set of non-inferior solutions than that based on the fullness storing rate.The proposed method could provide reference and practical guidance for the water storage operation of cascade reservoirs.