考虑各月生态流量变化约束的梯级小水电多目标优化调度研究

Study on multi-objective optimization scheduling of cascade small hydropower stations with inclusion of monthly ecological flow variation constraints

摘要

【目的】针对当前多目标优化调度研究多集中于中大型水库群和水电站的年际和年内生态流量变化，缺少山区河流梯级小水电生态流量月际约束研究不足的问题。【方法】以流溪河流域内三座梯级小水电(良口坝、青年、胜利)为研究对象，在各月生态流量约束的基础上，构建梯级水电站的多目标优化调度模型，以发电量最大和生态缺水溢水量最小为目标，采用非支配遗传算法(NSGA-Ⅱ)求解，结合Knee Point法优选调度方案，并与基于Tennant法(10%~80%标准)的固定生态流量方案进行对比。【结果】结果表明，月优化调度方案全年发电量较Tennant方案提升13%,生态缺水溢水量减少12%。三座电站发电量分别提高26%、32%和26.7%;生态流量约束上限的提升使高负荷运行时生态缺水显著降低，实现发电与生态效益同步优化。【结论】研究结果为面向生态与经济效益提升的山区河流梯级小水电多目标优化调度与管理提供了科学依据和技术支撑。

Abstract

[Objective] Current research on multi-objective optimization scheduling primarily focuses on interannual and intra-annual ecological flow variations in medium-and large-scale reservoir groups and hydropower stations, while research on monthly ecological flow constraints for cascade small hydropower stations in mountainous rivers remains limited. [Methods] Three cascade small hydropower stations(Liangkou Dam, Qingnian, and Shengli) in the Liuxi River Basin were selected as the research objects. A multi-objective optimization model for cascade hydropower stations was established based on monthly ecological flow constraints. The model aimed to maximize power generation and minimize ecological water shortages and spillages, and was solved using the non-dominated sorting genetic algorithm(NSGA-Ⅱ). Optimization scheduling schemes were selected using the Knee Point method and compared with a fixed ecological flow scheme based on the Tennant method(10%~80% standard). [Results] The result showed that the annual power generation under the optimized monthly scheduling scheme increased by 13% compared to the Tennant method scheme, while ecological water shortages and spillages were reduced by 12%. The power generation of the three stations increased by 26%, 32%, and 26.7%, respectively. The increase in the upper limit of ecological flow constraints significantly reduced ecological water shortages during high-load operations, achieving simultaneous optimization of power generation and ecological benefits. [Conclusion] The findings provide a scientific basis and technical support for the multi-objective optimization scheduling and management of cascade small hydropower stations in mountainous rivers, enhancing both ecological and economic benefits.

关键词

生态流量 / Tennant法 / 月频率法 / 梯级水电站 / 生态调度 / NSGA-Ⅱ / 影响因素

Key words

ecological flow / Tennant method / monthly frequency method / cascaded hydropower station / ecological scheduling / NSGA-Ⅱ / influencing factors

基金资助

国家自然科学基金项目(51979043)

广东省自然科学基金项目(2021A1515010723)