Study On Combined Operation Of Cascade Power Generation And Ecology In The Lower Reaches Of Jinsha River And Three Gorges

The construction and operation of the cascade hydropower stations in the lower reaches of Jinsha River and the Three Gorges project have changed the natural hydrological situation of the basin,blocked the migration channels of fish,affected the natural habitat and reproduction of fish,and destroyed the river ecosystem in the reservoir area.The ecological problems caused by the operation of reservoirs in the basin have been proposed since the last century,and have become more prominent in recent years,which has seriously affected the stability of the basin’s ecosystem.Therefore,the traditional operation mode should be changed,which is not limited to power generation,water storage and navigation operation,and ecological operation objectives should be fully considered to ensure the ecosystem security of the basin This problem needs to be solved.It is the best solution to deal with the ecological problems caused by reservoir group operation by implementing multi-objective ecological operation scheme and restoring the stability of basin ecosystem.First of all,taking the river basin dispatching project as the research object,the paper generalizes the elements of dispatching objects and river channels in the basin,draws the topological relationship diagram of cascade hydropower stations in the lower reaches of Jinsha River and Three Gorges,and builds the model of cascade hydropower stations in the basin,which provides the basis for the follow-up multi-objective ecological dispatching research.In the NSGA algorithm,the selection and mutation process of genetic algorithm are improved,and differential evolution algorithm(DE)is introduced.At the same time,the search strategy of nsde algorithm is improved to improve the convergence of nsde algorithm.The reliability of nsde algorithm is proved by example analysis,which provides algorithm support for multi-objective optimization scheduling in the future.Secondly,taking the downstream of Jinsha River and Three Gorges cascade hydropower stations as the research object,the multi-objective ecological operation model of cascade hydropower stations in the lower reaches of Jinsha River is constructed by generalizing the main and tributaries of the hydropower stations,and comprehensively considering the objectives of power generation dispatching and ecological dispatching The nsde algorithm is used to solve the model,and the results are analyzed qualitatively and quantitatively.The conclusion can be used to guide the ecological regulation of the four major fish species in the basin.Finally,based on the existing research results of Chinese sturgeon,namely the weighted area flow relationship curve of physical habitat,a multi-objective ecological operation model of cascade hydropower stations in the lower reaches of Jinsha River and Three Gorges hydropower stations during the impoundment period is constructed.The maximum power generation and storage capacity are the objectives of power generation and water storage at the end of the period,and the maximum weighted area of physical habitat of Chinese sturgeon is taken as the objective of ecological regulation.Furthermore,nsde algorithm is used to solve the model,and the feasibility of carrying out ecological dispatching in different level years is demonstrated through case analysis,and reliable quantitative analysis is also provided,which provides effective help for the ecological regulation research of Chinese sturgeon as the target species in cascade hydropower stations.