Study On Combined Optimal Dispatch Of Jin Ping Casecaded Hydropower Stations Considering Ecological Flow Requirement Of De-watered River Channel

Aiming at the water ecology and water environment problems of the downstream de-watered river channel after the development of Jinping cascaded hydropower stations,study on combined optimal dispatch of Jinping casecaded hydropower stations considering ecological flow requirement of the downstream de-watered river channel is carried out.Based on optimization modelling and scenarios analysis,monthly and daily time scale optimal dispatch strategies are proposed for the Jinping cascaded hydropower stations.Main contents and results are as follows.Firstly,according to the results on ecological flow requirement of the downstream de-watered river channel of Jinping-?reservoir,monthly and daily ecological flow requirement process are proposed.Based on the inflow characteristics,regulation capacity,water and hydraulics relation and operation characteristics,monthly and daily time scale multi-objective combined optimal dispatch models are developed with the ecological flow requirement considered.Optimization methodology based on pareto optimality and genetic algorithm is also proposed.Secondly,monthly optimal dispatch strategies in the drawdown season are obtained for the Jinping cascaded hydropower stations.For dispatch with priority on ecological objective,water release of Jinping-? hydropower station should be scheduled to satisfy the ecological flow requirement process.Relatively uniform daily average water release process should be implemented to decrease water head loss of Jinping-?hydropower station,by which total amount of electricity generation and its profit increase.For dispatch with priority on electricity generation objective,in order to increase water head of the Jinping-?hydropower station,water release of Jinping-?hydropower station should be regulated according to the inflow condition to slowly lower the water level.Jinping-?hydropower station also should be scheduled with a down water level process or a lower water level.Besides above,relatively uniform daily average water release process should be implemented to decrease water head loss of the Jinping-?hydropower station,.Thirdly,monthly optimal dispatch strategies in the flood season are proposed for the Jinping cascaded hydropower stations.In order to satisfy the ecological flow requirement and increase the total amount of electricity generation and its profit,water release of the Jinping-?hydropower station should be scheduled to form a special daily water level process which rise first and fall later.Jinping-?hydropower station also should operation with a down water level process or a lower water level.Besides above,relatively uniform daily average water release process should be implemented to decrease water head loss of the Jinping-?hydropower station.When the inflow of Jinping-?reservoir exceeds a certain value,flood control dispatch should be implemented and hydropower stations should operate with the maximum available output.Fourthly,daily optimal dispatch strategies are proposed for the Jinping cascaded hydropower stations.In order to satisfy the ecological flow requirement and increase the total amount of electricity generation and its profit,daily peak regulation should be implemented.Reserve regulation capacity of the Jinping-?reservoir should be utilized by which Jinping-?hydropower station operate with a down water level process or a lower water level at the peak-load and medium-load time.