Dynamic Control of Yearly Drawdown Level of Overyear Regulation Reservoir in Cascade System

Abstract

Based on the joint scheduling model of cascade reservoirs and a dynamic programming (DP) algorithm, this paper studies the optimal control of the yearly drawdown level of an overyear regulation reservoir considering the influence of inflow uncertainty. An innovative dynamic control method has been put forward, and the corresponding technical route is provided. In case study, the seven reservoirs of the Yalong River are used as the research object, the proposed dynamic control method is verified by a detailed case study, and yearly drawdown level dynamic control bounds of the Lianghekou reservoir under two inflow series are constructed. Based on a long series of historical inflows, the simulation calculation and detailed comparative analysis are carried out. It is found that the dynamic control bound constructed by the selected inflow series has little impact on the fluctuation of scheduling results and can well cope with the impact of inflow uncertainty on the scheduling results. In addition, compared with the traditional fixed-yearly-drawdown-level control mode, the proposed dynamic control method can consider the interannual difference of inflow, which can increase the total power generation of the cascade system by more than 94 billion kWh at maximum and realize 63.4%~76.3% of the benefits of the lifting space of yearly drawdown level optimization.