我国水电资源总量居世界第一，水电资源是可持续能源，也是我国现有能源中唯一可以大规模经济开发的能源。在全球能源紧缺和我国电力需求持续增长的严峻形势下，优先开发水电是国家制定的基本能源战略和方针政策。本文在对水电站系统进行分析的基础上，建立了基于动态仿真技术的水电站财务计算模型——该模型为框图式模型，对水电站的“蓄水发电-财务计算”流程进行了描述。因为考虑到了水库弃水，而弃水会减少可供发电的水量，所以该模型特别适合用于小水库水电站的财务计算（因为小水库水电站的弃水量较大）。然后结合实证进行了仿真编程和优化分析，为水电站装机容量的优化提供了一种“基于随机性和统计理论”的新思路。
本文内容分为四个部分：
（1）理论部分
首先对传统的经济评估方法做了回顾，对计算机仿真、模型的概念和特点进行了阐述；其次对离散事件系统及其仿真做了介绍；再给出了本文采用仿真方法建立财务计算模型的理由；最后讨论了影响最优装机容量的因素。
（2）模型研究部分
首先，在分析了水电站系统中的实体及其属性的基础上，讨论了本文拟建立模型的目标、河流来水量的处理、经济评价指标的选择、模型假设以及发电量和财务的具体计算规则。然后建立了本文的水电站财务计算仿真模型，该模型的主要特点是：模型的输入——河流的月份来水量，为遵循水文资料统计分布的随机数。在建模之后，总结了基于该模型对装机容量进行优化的基本流程和详细步骤，这里用到了统计学的知识。
（3）实证研究部分
以某小水库水电站项目为例，按模型研究部分总结的“基于统计原理的装机容量优化步骤”进行操作，针对遵循水文资料统计分布的来水量，实现了对该项目装机台数的优化。然后针对“建设投资、年运营成本和出厂电价”做了财务敏感性分析（而年发电量由河流来水量和水库容积决定，本文已用“仿真方法+随机模拟法+统计”对其做了研究，因此不再做发电量的财务敏感性分析）。
（4）比较和扩展
结合第4章实例研究部分的数据，将水电站传统的净现值计算方法和本文的净现值计算方法做了比较，指出了本文方法的特点；再在考虑出厂电价和年运营成本变化的基础上，对原水电站案例重新进行了装机台数优化，得到了稍有变化的结果。
最后对全文做了总结，说明了本文的创新和不足，并对今后的研究工作提出了展望。

The total amount of hydropower resources of our country is the largest in the world. Electricity resources coming from water is sustainable energy, and is also the only existing large-scale energy suitable to the economic development. Under the serious situation of global energy shortages and the continued growth of China's electric power needs, the priority development of hydropower are a nationally basic energy strategy and the principles of policies.
In this paper, on the basis of analyzing the hydropower station system, we establish a financing calculation model of the hydropower station based on the dynamic simulation technology——this model which belongs to the block diagram model, describes the process of “reserving water and generating power-calculating finance”. Because taking the abandoned water from reservoir into account, and the disposable water will reduce the water quantities for power generation, so the model is particularly suitable for the financial calculation of small reservoir hydropower station (Because the disposable water from small reservoir hydropower station is much large) .Then, we combine an actual case to compile a simulation program and make an optimization analysis, which provides a new idea for the hydropower station’s capacity optimization based on the randomicity and the statistical theory.
This paper is divided into four parts:
(1) The theory part
First of all, we do a review on the traditional economy assessment methods, and describe the concepts and features about the computer simulation and model; secondly, the discrete event system and its simulation are introduced; thirdly, we give the reasons for establishing the financing calculation model based on the simulation method; finally, the factors affecting the optimal capacity are discussed.
(2) The model part
On the basis of analyzing the entities and their attributes of hydropower system, we discuss the objectives of the proposed model, the treatment of river’s water coming amounts, the selection of indicators for economic evaluation, the assumptions of the model, as well as the particular calculating rules of generating quantity and financing.Then this paper’s simulation model of financing calculation is set up.The main features of the model, is the input——the river’s water coming amounts in a certain month, which follow the distribution of hydrologic data. After that, based the model we summed up the basic processes and the detailed steps for optimizing the installed capacity of generating units. Here the statistical knowledge is used.
（3）The part of empirical research
To a certain small reservoir hydroelectric project as an example, according to “the optimizing steps for installed capacity based on the statistical theory”, we operate these steps. For the water coming quantities that follow the distribution of hydrologic data, we achieve the optimization of installed capacity. And then we make a financial sensitivity analysis about the construction investment, the annual operating costs and the power price(The generation capacity is decided by water coming quantities from the river and reservoir’s capacity, and this article has used "Simulation+ stochastic simulation methods +Statistics" to study it, so it is no longer do the financial sensitivity analysis about the generating capacity).
（4）Comparison and extension
Combining the data of Chapter 4, we do a comparison about the hydropower station between the traditional method of calculating the net present value and the net present value calculation method of this article, and point out that the characteristics of this paper’s method. Then, considering the price and annual operating costs’s changes, we make an installed capacity optimization about the original hydropower station case, and get a result with slight changes.
Finally, we summarize for the paper, illuminate the innovation and the lack, and raise the outlook for the research work in the future.