【作者】 张新明；

【导师】 王丽萍；

【作者基本信息】 华北电力大学 ， 管理科学与工程， 2014， 博士

【摘要】 水电是相对清洁同时又可再生的优质能源,能将一次能源直接转化为二次能源——电力,同时较之其他能源还具有发电成本低、机组启停迅速、调峰调频能力强、减排作用大等优势,因此国内外均高度重视水电的发展。随着国家“节能减排”、“西电东送”等政策的推出及实施,我国水电事业的发展继续稳步增进,呈现各大流域梯级水电站水库群大规模开发建设并逐渐投入运行的局面,这对我国水资源优化配置,水电流域梯级系统的管理提出了更高的要求。针对目前我国水电能源利用效率低、供需矛盾等现状,本文以水电站水库(群)为研究对象,鉴于水库中长期径流预报及水电站水库(群)短期优化调度在理论与实际应用中所具有的重要位置,对两个方面进行了深入细致研究,这对于完善水库调度运行管理理论体系,提高水资源的整理利用效益,促进社会、经济、生态环境的可持续发展具有重要意义。全文取得的主要研究成果如下：(1)BP网络激活函数选择及在径流预报模型中的应用。针对传统BP算法训练时间长、收敛速度慢、局部收敛等固有缺陷,通过深入分析BP网络结构中各基本要素,找出模型中起决定性作用的激活函数影响因子。设计混合水平全排列组合试验方案,建立相应的评价指标体系,采用极差分析法对激活函数进行灵敏度分析。实例结果表明,BP网络不同层激活函数的组合工况对预报模型的收敛速度、收敛精度及泛化推广能力具有重要影响。合理巧妙地选择隐含层与输出层激活函数的组合工况,既能保存标准BP模型结构简单计算效率高的特点,又能提高计算精度,对传统模型的固有缺陷具有一定的改善作用。(2)基于BP激活函数灵敏度分析的中长期径流组合预报模型。以中长期径流组合预报模型为研究对象,引入预报精度和预报稳定性两个评价指标,采用“分项总和法”确定各单一模型权重,建立组合预报模型。设立混合水平全排列组合试验方案,应用极差分析法进行实例模拟仿真。该组合模型在保证标准BP模型简单,逻辑清晰等特点的同时,又提了高组合模型预报精度及稳定性。为组合模型权重的确定提供新的方法,具有一定指导意义。(3)考虑负荷曲线的水电站群短期运行自优化模拟模型。水电站群短期优化调度处于连接中长期优化调度与厂内经济运行的枢纽位置,其调度规则具有较大的生产实用价值及实施调度意义。本文首次将自优化模拟技术引入到水电站短期优化调度问题求解中,提出了一种基于负荷曲线的自优化模拟模型。将优化与模拟技术结合,在模拟模型中嵌入自动辨识反馈环节,利用自优化模拟技术物理意义明确、仿真性好、不受维数限制、并可借助累计经验进行人为调整的特点,构建了四层辨识反馈结构及目标优化结构来对模型进行模拟求解,确定短期优化调度方案。通过在金沙江中游梯级水库群短期调度研究中的应用,证明该模型技术路线和求解思路先进,计算结果可靠,在短期优化调度实用化方面具有一定的创新性及拓展性。(4)基于二维非恒定流模型的水电站群短期调度方案研究。以澜沧江景洪-橄榄坝两水库系统为研究对象,考虑景洪-橄榄坝两坝间V级河道通航要求,及橄榄坝水库作为澜沧江最后一级调节水库,其出境径流将受到国际流量限制的情况,从兼顾高航运要求与水电站发电效益两目标角度出发,建立了考虑河道流场变化的二维水动力非恒定流数学模型。在考虑上游有小湾、糯扎渡水电站联合运行的工况下,以混合非结构网格离散计算模型,采用Roe格式的近似Riemann解来计算通过界面处的法向通量,计算出各运行方案下景洪-橄榄坝间的水力指标值。模型在兼顾梯级发电调度和下游通航要求的前提下,为景洪-橄榄坝联合运行提供具有实际应用价值的调度方案,解决了中短期发电调度中考虑二维非恒定流约束的难点。更多还原

【Abstract】 Hydropower is the relatively clean, renewable and high-quality energy, and it can be directly converted to a secondary energy, that is electricity. Compared to other energy, hydropower has some advantages, such as low generation costs, rapid unit commitment, strong peaking FM capability, efficient emissions reduction and so on. So both at home and abroad, people attach great importance to the development of hydropower. Recently out country is launching and implementing the "energy saving","west to east" and other policies, and the steady and continuous promotion of hydropower plays an important part in practicing these policies. At present the development and construction of Hydropower shows the characteristics of large-scale, complicated and so on, therefore it puts higher requirements for the optimal allocation of resources, and the scheduling of cascade hydropower stations. At present, the basic situation of Chinese developed hydropower is low efficiency and large waste, so in order to solve the problem, this paper has done a strict and in-depth research taking the hydropower reservoirs (group) as the study object. As is known to all, the long-term runoff forecast and the short-term optimization scheduling has an important position in theory and practice, so research on the two aspects has important implications for perfecting reservoir management theory, improving water use efficiency, and promoting the sustainable development of social, economic and the ecological environment. The main achievements of the whole paper are as follows:(1) The activation function of BP network and its application in runoff prediction model. The traditional BP algorithm has some inherent defects, such as long training time, slow and local convergence and so on. Through analyzing each essential element of the BP network structure in depth, it finds that the activation function factor plays an important role in modeling and model effect. Taking the commonly used activation function in the current BP network model and its improved model as the research object, it designs the mixed level of the whole permutations test program, establishes the appropriate evaluation system, and choses the range analysis method to analyze the sensitivity of the activation function. The results of the examples shows that the different combination of activation function in the layers has important influence on the convergence rate, the convergence precision, and the generalization ability of forecasting model. So a reasonable combination of the hidden layer and output layer activation function can not only save the simple structure and computational efficiency of BP model, but also improves the accuracy of certain predictions. (2) The medium and long term runoff combination forecast model based on the sensitivity analysis of BP activation function. BP network model is often selected as one of the factors in combination forecasting model. Taking the of long-term runoff combination forecast model for study, it introduces the forecast accuracy and stability two evaluation index, and use the objective entropy weight method and subjective G1to determine the relative importance of the two indicators, and then take the variance-covariance method to determine the index weight of each single model, finally gets the combination weights of each single forecasting model. On this basis, the long-term runoff forecasting model has been established based on a sensitivity analysis of the BP network activation function. In the example application, choosing the mixed level of the whole permutation test program and range analysis method to solve the model, and the results have given the based reasonable suggestions on how to choose the activation function combination of BP network. The suggestion saves the characters of BP algorithm, such as simple, logical, and high efficient calculation, simultaneously it improves the prediction accuracy and stability of the forecast model.(3) Self-optimization simulation model of short-term cascaded hydroelectric system dispatching based on the daily load curve. Short-term optimization scheduling of hydropower stations has the great significance in practical production and the implementation scheduling, because it directly connects the long-term optimization scheduling with the plant economic operation. In the actual grid scheduling, hydropower power system has the tasks of FM and peaking, so from the electrical side, the power output progress should be consistent with the system load curve as far as possible; and from the generation side, it should try to improve the efficiency of power generation and peaking. In order to take into account the need of the electrical power requirements of both sides, the optimization simulation model based on the load curve has been proposed. Combining optimization with simulation technology, the automatic identification of feedback has been embedded into the normal simulation model, with the advantages of the self-optimization simulation technology) a four layer identification feedback structure and the optimization structure have been set up to determine the short-term optimal scheduling. And taking the middle reach of the Jinsha River reservoir as an example for simulation calculation, the application shows that the research has a certain degree of practicality and feasibility.(4) Research on short-term scheduling of two-dimensional unsteady flow mathematical model. Hydropower system with multi-objective analysis of flood control, navigation, power generation and other requirements, should formulate a reasonable scheduling scheme to achieve the coordination of the target objective, which is of great significance to make full use of the water resources. In Jinghong-the olive dam reservoir system, the requirements of river navigation between the two dams is V, at the same time, the olive dam reservoir is the last regulating reservoir in Lancang River, and its exit runoff will be restricted by the international rivers flow restriction. From the point view of the two target, a two-dimensional hydrodynamic unsteady flow model is established considering the change of river flow field. Considering the conditions of the joint operation of Xiaowan and Nuozhadu Hydropower, seven typical daily operation scheme have been established for Jinghong-Olive dam. The model selects hybrid unstructured grids to discrete computational domain, uses the approximate Riemann of Roe format solution to calculate the interfacial normal flux, finally it recommends scheduling scheme with practical application value for the joint operation of Jinghong-olive dam reservoir system.更多还原