大型水电工程物资调运建模及算法

根据小湾水电工程物资供应管理的实际情况,提出了物资调运的三级节点概念模型,论述了物资采购与调运的数学模型,并给出了具体算法。模型已应用于该工程物资调运决策支持系统中,运行实践表明,该模型能够辅助调度人员制定合理的物资采购与调运方案。     

基于区域分解算法的地下水耦合模型及其应用

根据岩体中不同区域裂隙发育规模的差异分为连续区域和离散区域,在不同区域中使用不同的地下水运动数学模型,应用区域分解算法来解决这类问题。其中连续区域采用了等效连续介质模型,离散区域采用了随机裂隙网络模型,通过区域公共边界上水位和流量连续的条件将两模型耦合求解。将基于区域分解算法的耦合模型应用于锦屏水电站坝址区三维渗流场的模拟中,通过钻孔观测水位和计算水位的对比发现,该方法是有效的,能够应用于实际工程。     

Optimization of the production of hydroelectric power systems with a variable head

We present in this paper a new approach for optimization of the production of hydroelectric power systems with a variable head. The problem is formulated as a minimum norm problem.The method takes into account the water head variation. To avoid underestimation of production for rising water levels and overestimation for falling water level, an average head (of begin and end of time step) is used. The method also takes into account the stochasticity of the river flows. Numerical results for a real system in operation including up to six reservoirs are reported for different water conditions. The proposed method is computationally efficient compared to other approaches.This work was supported by the National Research Council of Canada, Grant No. A-4146. The authors would like to acknowledge the data obtained from British Columbia Hydro.     

Long-term optimal operation of a parallel multireservoir power system

Long-term optimal operation of a multireservoir system is complex because it is a dynamic problem (present decisions for one reservoir depend on future decisions for all reservoirs); the optimal operating policy for one reservoir depends not only on its own energy content, but also on the corresponding content of each one of the other reservoirs; it is a highly stochastic problem with respect to the reservoir inflows and it is a nonlinear problem. This paper presents a new method for determining the optimal monthly operating policy of a power system consisting of multireservoirs on a multiriver system taking into account the stochasticity of the river flows. Functional optimization techniques and minimum norm formulation have been used. Results for a numerical example composed of three rivers with four reservoirs, three reservoirs, and two reservoirs on each river, respectively, are presented.This work was supported by the National Research Council of Canada, Grant. No. A4146.     

An enhanced decomposition algorithm for multistage stochastic hydroelectric scheduling

Handling uncertainty in natural inflow is an important part of a hydroelectric scheduling model. In a stochastic programming formulation, natural inflow may be modeled as a random vector with known distribution, but the size of the resulting mathematical program can be formidable. Decomposition-based algorithms take advantage of special structure and provide an attractive approach to such problems. We develop an enhanced Benders decomposition algorithm for solving multistage stochastic linear programs. The enhancements include warm start basis selection, preliminary cut generation, the multicut procedure, and decision tree traversing strategies. Computational results are presented for a collection of stochastic hydroelectric scheduling problems.     

A control method for speeding up response of hydroelectric station power canals

A control method which, through the suitable servo-operation of the check gates, attains a consistent improvement in the speed of response of hydroelectric power canals is presented. Its application allows the size of the canal headpond to be reduced at the design stage of the power station as well. The proposed method is based on the constant volume control concept and uses a mathematical model of the power canal derived from linearization of the Saint-Venant equations. The results of the computer simulation of a controlled real system's dynamic behavior obtained through the use of the method of characteristics are presented.     

Modelling and optimization of reservoirs for long-term regulation with variable head using functional analysis

In this paper, functional analysis and minimum norm formulation are applied to maximize the total benefits from two hydro reservoirs. The hydroelectric power generation is treated as a nonlinear function; water head variation and stochasticity of the river flows are included. The resulting problem has a nonlinear objective function and linear constraints. The proposed method is computationally efficient, compared to previous techniques. Numerical results are presented for widely different water conditions for an actual system in operation.This work was supported by the National Research Council of Canada, Grant No. A4146. The authors wish to thank B. C. Hydro for providing the reservoir data.     

论类梯度筛选算法的无效性

本文简要介绍了水能资源梯级开发顺序最优化研究中著名的“类梯度筛选算法”,在实践中给出了该算法的一个反例,并在理论上证明了该算法的无效性.     

Optimal operation of multireservoir power systems

The optimal monthly operating policy of a multireservoir hydroelectric power system is a stochastic nonlinear problem. This paper presents a new method for determining the optimal monthly operating policy of a power system ofn reservoirs in series on a river taking into account the stochasticity of the river flows. Functional optimization techniques and minimum-norm formulation have been used to find the optimal release policy of the system. Results for a numerical example composed of four reservoirs are presented.This work was supported by the National Research Council of Canada, Grant No. A4146.     

On the inefficiency of the quasi-gradient screening algorithm

In this paper, the well-knwon quasi-gradient screening algorithm on optimal sequencing cascaded development of water energy resources will be introduced. Then we will given a contraexample in practice and prove the inefficiency of the algorithm in theory.