Optimal dispatching rules of hydropower reservoir in flood season considering flood resources utilization: A case study of Three Gorges Reservoir in China

Abstract

Making full use of flood resources on the basis of ensuring flood control safety plays a positive role in improving the comprehensive benefit of reservoirs during flood season. To improve the utilization rate of flood resources of hydropower reservoirs, taking the Three Gorges Reservoir (TGR) as an example, an optimal forecast dispatching model for flood resources utilization (FRU) in flood season is established first based on the safety requirements of flood control, combining the power demand and the safe operating conditions of the power grid. Then, considering the uncertainty of runoff forecast, the stochastic simulation method of inflow forecast based on the gaussian mixture model (GMM) is used to assess the flood control risk of FRU dispatching. Finally, the optimal dispatching rules of TGR in flood season considering FRU are derived by using the gradient boosting regression tree (GRBT). The experimental results show that the optimal dispatching rules can effectively improve the utilization rate of flood resources and increase the generation benefit of TGR during flood season without an additional increase in flood control risk. Compared with routine dispatching, the hydropower generation of the TGR by rule dispatching considering inflow forecast information of 3, 5, and 7 days can be increased by 3.38%, 5.57%, and 6.93% respectively. This shows that the dispatching rules derived are very reliable and promising, which can provide decision support for reservoirs operation in flood season.