Multi Objective Ecological Operation And System Architecture Design Of Cascade Reservoirs Based On Hydrological Variation

China has built large-scale hydropower bases on the Yangtze River,Yellow River,Jinsha River,Wujiang River,Lancang River and other major rivers.By the end of 2020,China’s total installed hydropower capacity will reach 370 million kilowatts,ranking first in the world.However,cascade reservoirs make great contributions to the national energy structure reform and power system stability,and also have a huge impact on the ecological environment of the basin.It is difficult to solve the problem of cascade reservoir group operation under the new situation of resource protection by traditional operation theory and method with single objective of economic benefit.It is urgent to seek new ecological operation theory,model and technology and carry out research.Therefore,this paper takes the cascade reservoirs from the lower reaches of Jinsha River to the Three Gorges as the research object,studies the river ecological water demand under the condition of hydrological variation,establishes a multi-objective ecological operation model with minimum ecological water shortage,overflow flow and maximum power generation,proposes a multi-objective particle swarm optimization algorithm with multi group cooperation,and designs a distributed decision support system architecture for ecological operation of cascade reservoirs.The main research contents and innovative achievements are as follows:(1)In order to study the change of hydrological regime in the lower reaches of Jinsha River to the main stream of the Three Gorges after the construction and operation of the water control project,and the impact of the destruction of the hydrological consistency of the river on the calculation of ecological water demand,based on the analysis of the flow hydrological series of Pingshan station and Yichang station over the years and combined with the hydrological investigation,the hydrological variation points of Pingshan station are diagnosed as 1944 and 1997,The hydrological variation points of Yichang station are 1968 and 2000.Furthermore,the upper and lower limits of ecological water demand from the lower reaches of Jinsha River to the main stream of Three Gorges are calculated according to the hydrological state of variation points,and the optimal ecological flow corridor is proposed.The results show that,compared with other hydrological conditions,the ecological water demand process under natural condition is most suitable for the spawning and hatching needs of Chinese sturgeon and four big fish,which provides physical support for the multi-objective ecological operation of reservoir under the condition of hydrological variation.(2)In order to explore the relationship between ecology and power generation objectives in cascade reservoir group operation from the lower reaches of Jinsha River to the Three Gorges under the condition of hydrological variation,an ecological operation model with the objectives of maximum cascade power generation and minimum ecological water shortage and overflow was established,Then,a multi-objective particle swarm optimization algorithm(mgcmo-pso)is proposed to solve the above scheduling model.The case study shows that mgcmo-pso algorithm can obtain the Pareto front with uniform distribution,effectively overcome the shortcomings of slow convergence speed and easy convergence to local optimum,and reduce the ecological water shortage and overflow while meeting the demand of power generation optimization of cascade hydropower stations,which provides a new idea for multi-objective ecological operation modeling of reservoir group.(3)Aiming at the problems of different development standards,high development difficulty and slow development progress of domestic water dispatching system,a distributed decision support system architecture for ecological operation of cascade reservoirs is proposed,and a functional system for ecological operation of water dispatching system is designed.Among them,in order to enhance the scalability of the system and make it have the characteristics of low coupling,a three-tier architecture of the water dispatching system is established,the back-end distributed micro service integration method and the front-end visualization method are designed in detail,and the multi-objective ecological dispatching decision support system of cascade reservoirs is built by applying the designed architecture and the proposed integration method,It provides a complete implementation method for system development.