Study On The Three Gorges And Jinsha River Downstream Cascade Reservoirs Power Generation Optimal Operation

The hydropower resources between the Three Gorges and the downstream ofJinsha River are abundant, which is an important river section for exploitation ofhydropower resources in Yangtze River. The Three Gorges is water control projectscheduling in the stem stream of Yangtze River, which is responsible for coordinatingflood control, navigation, power generation, hydro-meteorological etc. Consideringthe factor of flood control, water supply and irrigation, the object of Jinsha Rivercascade hydroelectric stations is power generation. The cascade hydroelectric stationssystem is very large, which has more joint operation benefit and same region of powersupply, providing some conditions for joint operation. There are some gaps betweenactual application and the research, due to the long hydropower stations constructioncycle, the restrictions of predicting operation conditions and little research on stationsoperation. The partition of power plant and power network, bring cascade reservoiroptimal operation come true provide reference for generation plan being reported toelectricity grid system.Cascade stations optimal operation is a high dimensional constrainedmulti-objective problem with complex characteristics, such as uncertainty, nonlinearand multi-objective, etc, which is an interdisciplinary research field in hydro scienceand complex system engineering. However, along with the rapidly exploitation ofhydropower resources, the hydraulically and electrical relationship among cascadehydroelectric stations become more and more complex, moreover, the conflictsamong multiple operational objective are more obliviously. Traditional optimaloperation theories and techniques cannot fully exert the comprehensive benefit of thelarge-scale cascade hydroelectric stations, and new joint operation anddecision-making theories and methods are necessitated in present. In this research, weaim at the joint generation operation decision-making problems of The Three Gorgesand Jinsha River downstream (TJ) cascade hydroelectric stations, studying ongeneration optimal operation and multi-objective decision-making based on Paretomulti-objective optimization. With the objective of generation benefits, we adoptcomplex system modeling, intelligent evolutionary into solving model, whichproviding reference for making generation plans. The store time of cascade reservoiris decided based on considering store risk and hydrological factors. Meanwhile,reservoir store energy rule our research. A series of research results in joint optimaloperation and decision-making of large-scale cascade hydroelectric stations are obtained. The main content of the innovation and contribution in this thesis are listedas follows:(1) There are some effects on The Three Gorges operation after the Jinsha Riverdownstream cascade reservoirs are built. We analyze the conflict and competitiverelationships among multiple operational requirements with Three Gorges powergeneration model by introducing the concept of Pareto optimal based on theprecondition of Jinsha River downstream cascade reservoir operation. We explain thebasis of multi-objective model, and adopt NSGA-Ⅱalgorithm to solve model byintroducing efficient storage. The results show that proposed VNSGA can deal withabove multi-objective operation model effectively and provide better Pareto foroperational decision makers, which can provide the reference for reservoir operationmulti-objective optimization problem. Based on the conflict and competitiverelationships among multiple operational requirements, we can discover powergeneration optimal operation.(2) Considering the power generation demand of TJ cascade stations jointoperation, we establish optimal models of The Three Gorges and TJ cascade stations,and adopt dynamic programming, genetic algorithm and particle swarm optimizationto solve the problem. In order to overcome the limitation of the theories, a modifiedgenetic algorithm and particle swarm optimization is proposed to improve optimalcapacity by improving diversity of population and weight, which is technicalbreakthrough for solving model. The obtained results show that modified algorithmscan solve those problems with fast convergence rate and high precision, thus weprovide a new efficient way to slove optimal operation problems. It has improvedcompute speed by inserting parallel computing.(3) Base on an analysis of TJ cascade reservoir factors and hydrological factors,with the objective of reservoirs refilled rate, we decide the store time of Jinsha Riverdownstream reservoirs. Then, there are some possibilities for The Three Gorges tostore water ahead of time.(4) As a group, electric power company should distribute power properly aftertaking generation plan, which makes electric grid system safety and optimizes the useof water resource. To enhance the enforcement of electrical system after issuingpower generation plan, the cascade reservoir efficient storage is proposed and theequivalence model is established based on the reservoir energy storage rule, which isto guide the reservoir storage and release. Compare to K discriminant, the equivalence model has better comprehensive benefits to guide TJ cascade reservoirsdecision-making by different typical years, which provide some contributions forstudying on the rule of reservoir storage and release and carrying out generation plan.