溪洛渡-向家坝-三峡梯级水库联合蓄水方案与多目标决策研究

为协调好梯级水库联合蓄水调度过程中防洪、发电、蓄水和航运等目标之间的矛盾,实现各水库蓄水时机与蓄水进程的协同优化,以溪洛渡-向家坝-三峡梯级水库为例,推求了可权衡防洪与兴利之间矛盾的梯级水库联合蓄水方案,主要研究内容主要包括以下3个部分:(1)风险分析,推求了汛末各分期内坝前最高安全水位约束和联合蓄水方案的防洪风险;(2)兴利效益分析,分析了联合蓄水方案的发电和蓄水等兴利效益;(3)多目标决策,评价了联合蓄水方案的防洪风险、发电和蓄水效益,得出了最优非劣质蓄水方案。研究结果表明:溪洛渡-向家坝-三峡梯级水库的较优联合蓄水方案,分别为9月5日起蓄的同步起蓄方案和9月1日-9月5日-9月10日起蓄的异步起蓄方案,较原设计蓄水方案,年均发电量可分别增加23.76和20.43亿k W·h,增幅分别为3.25%和2.78%;蓄水率可由96.73%分别提高至97.51%和97.57%,两者均可在不降低原防洪标准的前提下,提高梯级水库的综合效益,前者的发电效益较优,而后者的蓄水效益较优。

Multi-objective decision and joint refill schemes of Xiluodu-Xiangjiaba-Three Gorges cascade reservoirs

In order to balance the contradictions between flood control and comprehensive utilization bene-fits and optimize the timing and process of refill synergistically, an integrated joint refill operation model consisting of a flood control risk analysis module used to derive maximum safety water level and risk,a uti-lization benefits analysis module used to analyze power generation and refill benefits and a multi-objective evaluation module used to evaluate flood risk, power generation and refillt benefits is proposed in this study to derive joint optimal refill rules for cascade reservoirs. The Jinsha River and Three Gorges cascade reservoirs in the Changjiang River basin of China are selected for a case study. The results show that the recommended joint optimal refill schemes are synchronous scheme with start time of refill operation on Sept. 5 as well as asynchronous scheme with start time of refill operation on Sept. 1,Sept. 5 and Sept. 10 for Xiluodu, Xiangjiaba and Three Gorges cascade reservoirs. Besides, joint optimal synchronous and asyn-chronous refill rules can generate 2.38 billion kW·h (3.25%) and 2.04 billion kW·h (2.78%) more annual average hydropower and improve fullness storage rate from 96.73% to 97.51% as well as 97.57% respective-ly for the cascade reservoirs without reducing originally designed flood prevention standards comparing with the designed operating rules.