三峡水库中期优化调度方法研究

Development of a Mid-term Optimal Operation Method for Three Gorges Reservoir

以建成后的三峡水库为研究对象，开发了一个基于入库径流预报的水库中期优化调度模型．所开发的优化模型使用离散动态规划法作为优化算法，模型中包括长期优化模块（时间跨度为一年，优化时段为一个月），中期优化模块（时间跨度为3～7d，优化时段为1d），和长中期优化模块之间的耦合环节．长期优化模块所输出的是月平均库水位，它被设定为中期优化模型所使用的离散动态规划法的终止状态，以此实现长中期优化模型的耦合．应用此优化模型进行三峡水库调度模拟的结果显示，这种耦合机制的设计是成功的：长期优化的库水位轨迹能很好地指导中期优化调度．利用开发的优化模型，研究了具有不同预见期的入库径流预报对发电效益的影响效益．发现在7d以内，入库径流预报的预见期越长，所获得的年发电量越大．在7d的预见期下，年发电量最大可达理论年最大发电量（8．85×10^10kW·h）的85％．

A mid-term optimal operation model is developed by taking into account of the inflow forecasts for the Three Gorges Reservoir. The discretized dynamic programming（DDP ） is used as the optimization algo- rithm for the model. The model consists of a long-term optimal operation module （with a time span of 1 year, and a time unit of 1 month）, a mid-term optimal operation module （with time spans varying between 3-7 days, and a time unit of 1 day） and a coupling mechanism between longand mid-term modules. The output of the long-term module monthly averaged water levels, are interpolated into daily water levels. The daily wa- ter levels are then set to be the terminal conditions of the mid-term module; therefore, the long- and mid-term optimization modules are coupled together. The developed model is applied to optimizing the operation of the Three Gorges Reservoir. The results show that the coupling mechanism is working successfully; the water level trajectory obtained from the long-term optimization can guide the mid-term optimization effectively. The developed model is also applied to investigating the effect of the lead time of the inflow dropower generation. The results show that, within 7 days, longer lead times lead to tricity. With a lead time of 7 days, the annual electricity generated can reach 85% of maximum electricity （8.85 ×10^10 kW · h）. forecasting for the hylarger amount of electhe theoretical annual