Research On Some Issues In The Joint Optimal Operation Of Cascaded Reservoirs Between Longyangxia And Liujiaxia

In this paper, considering the characteristics of the upstream cascaded reservoirs and related areas in the Yellow River Basin, focusing on the 6 cascaded hydropower stations between Longyangxia and Liujiaxia on the upper reaches of the Yellow River, the joint operation of hydropower stations and other related problems are studied.Firstly, taking the fact that China’s economic development has entered a new normal situation into account, the hydropower industry prospects are introduced; then, the macro background and the engineering background of the joint operation of cascade reservoirs are presented. Likewise, the purpose and significance of the research is invested.Analysis on domestic(foreign) reservoir(s) research is presented,with detailed study on the advancement of reservoir dispatching at home and abroad being also given and sorted. Lastly, we also analyse the main problems and development direction of reservoir operation.According to the specific situation of the upstream basin in the Yellow River, much attention is paid to relevant issues of the water conservancy existing in the research area. Hydropower development status between Longyangxia and Liujiaxia and technical and economical information concerning the 6 cascaded hydropower stations is listed, which lays a physical basis on the waterpower calculation, as well as the optimal dispatching on the cascade hydropower stations.According to the historical runoff data, the inflow, belonging to the upper reaches of the Yellow River, is analyzed by qualitative and quantitative methods. The wet and dry conditions, variation tendancy, water distruibuted composition in the Yellow River upper reaches is understood, providing data support for hydropower calculation and cascaded optimal scheduling.According to the existing data, Longyangxia and Liujiaxia, as the two backbone reservoirs, whose current operation pattern is discussed, focusing on the cause of the Longyangxia reservoir running in a low water level at the initial stage. The two reservoir complemented with each other, the characteristics of water storage in different years is analyzed.The characteristics of the two reservoirs discharge is discussed, especially Liujiaxia reservoir discharge process in the ice season and the new problem caused by Longyangxia reservior impounding excessively in the flood season.With long-term joint operation model of cascaded hydropower stations between Longyangxia and Liujiaxia being established, a thorough explanation of the successive optimization, coupled with genetic algorithm is given, in addition to its fundamentals, steps and matters calling for attention.Using C++ language, the algorithm programming process, the frame of the main program, and the subroutine module are introduced, with the detailed content of each function module involved.Then it is taken advantage of in reservoir optimization scheduling in practice. Based on the model, the average electricity of multi years generated by each of the cascade reservoirs is calculated, and the average monthly discharge flow process chart of Longyangxia and Liujiaxia is delineated in addition to the individual monthly dispatching chart of all the 6 cascade hydropower stations. Finally, the scheduling results and real requirements is compared.Analysis on the effects exerted on the joint operation by the initial water level of multi-year regulating reservoir is stressed. The study on the Longyangxia reservoir working againstinflow uncertainty is also considered.