Study On Ecological Power Generation For Cascade Hydropower Stations In Multi Objective Optimization Scheduling Model

Optimal operation of hydropower stations is a complex decision-making process, with multi objectives and multi attributes, multi levels and multi phases. It is not only related to the whole river basin, but also closely connected with the ecology of the lower reaches of the dam. The optimal operation mode of cascade hydropower station is divided into flood control operation and benefit scheduling. Due to the often only consider the flood control, power generation, water supply, irrigation and shipping and other social and economic benefits. So ignoring the effects of stress on river ecological system caused by the scheduling objectives, and led to the ecological environment of the river basin has been damaged to varying degrees. From the perspective of the protection of river ecosystem, the current dispatching of cascade hydropower stations way mainly exists two problems. One is downstream of the dam ecological protection and reservoir water environmental protection requirements is seldom considered to cascade hydropower station scheduling scheme, and the other is the lack of unified scheduling and management of water resources. Therefore, multi objective optimal scheduling of cascade hydropower stations based on Ecological scheduling has become a hot research topic.Firstly, the paper described the system method at home and abroad on the optimal scheduling of cascade hydropower stations and the research status of ecological regulation, summarizing a series of problems in optimal operation of cascade hydropower stations in China, and put forward the research ideas and content of this thesis.Secondly, the influence of the development of cascade hydropower stations on the river ecosystem was discussed from the aspects of hydrology, sediment, water temperature, water quality, soil, environmental geology, biological diversity and so on.Third, discusses the cascade hydropower theoretical basis for optimizing the scheduling of ecological station, basic principle and scheduling criterion, on the basis of this, the multi-objective mathematical model of ecological regulation of cascade hydropower stations is established. In this model, the water deficit index is used to reflect the benefit function of the ecological regulation of cascade hydropower stations, and using the weight coefficient to deal with the problem of multiple targets in the model. At last, the change range method(RVA) is introduced to optimize the scheme, based on the IHA of 32 hydrological changes to calculate the degree of hydrologic changes and quantization the ecological benefits. In order to evaluate the influence of the construction and operation of the cascade hydropower stations on the river.Fourth, calculation of ecological water demand in the lower reaches of the river of Longyangxia and other cascade hydropower stations in the upper reaches of the Yellow River. Then analyze the calculation results and proposing 9 kinds of ecological flow schemes in the calculation of the ecological water demand in the lower reaches of the river.Fifth, in the upper reaches of the Yellow River Longyangxia, Laxiwa, Lijiaxia and so on, four cascade hydropower station as an example to calculate. First of all these four cascade hydropower plants as a power station, and the above tour leading power station in Longyangxia as a typical. At the same time, multi objective optimal operation model of cascade hydropower stations is established. The genetic algorithm is adopted to combine the above 9 schemes, and the model is optimized, and the optimal discharge process of cascade hydropower stations is obtained. Eventually, by on nine kinds of schemes of economic benefit and ecological benefit evaluation and optimization to obtain the optimal schemes, the results of long series optimal operation of Longyangxia Hydropower Station under this scheme are obtained. At last, the results of the study are summarized and prospected.