三峡电站单机容量与发电量的关系研究

Study on Relation between Energy Output with Power Unit's Capacity of Three-Gorge Hydroplan

论述了分析计算的基础和三峡电站的运行特点,采用“直接计算方法”,研究了三峡机组容量对施工期和正常运行期发电量的影响。以梯级出力受阻最小、发电量最佳为目标,建立了梯级联合优化调度数学模型,利用不同季节不同来水情况下的模型计算结果分析率定了葛洲坝水库的坝前水位等参数。研究结果表明:①机组单机容量75.6万kW方案比70万kW方案,施工期累计多发电量13.66亿kW·h,正常运行期年均多发电量7.41亿kW·h;②施工期增发电量主要是大容量机组多利用水量的结果,正常运行期增发电量主要是机组最优组合效率提高的结果。

Considering the pecularities of Three-gorge Hydropower station and Gezhouba Hydropower station, according to the principle of that the obstructed power of the two cascade stations is minimum while the output of them is maximum, a mathematical model is formulated for comparing the efficiency between two schemes using generator capacity 756 MW and 700 MW respectively for Three-gorge Hydropower Station. The calculated result shows that the total energy output during the construction period of the scheme using generator capacity 765 MW is 1 366 MW · h more than that of the scheme using generator capacity 700 MW, because the water flow used for power generation of the former is more than that of the latter, and the annual energy of the former is also 741 MW·h more than that of the latter, because the efficiency of optimized combination of power units is raised.