基于改进NSGA-Ⅱ算法的梯级水电站多目标调度方法

Multi-objective Scheduling Method of Cascade Hydropower Stations Based on Improved NSGA-ⅡAlgorithm

近年来区域暴雨洪涝灾害的突发性、极端性、反常性显著增强,年内径流时空分布不均匀性进一步加剧,在梯级水电站汛期调度中均衡防洪与兴利任务成为重要研究课题。针对梯级水电站多目标联合调度问题,提出了一种基于NSGA-Ⅱ算法的求解方法,该方法改进了NSGA-Ⅱ算法的种群生成策略及精英选择策略,以梯级各电站时段平均防洪库容占用率作为防洪风险函数、梯级年发电量作为兴利目标函数,结合Pareto前沿分析方法求解了含防洪、兴利目标函数的梯级水电站联合调度问题。最后,以某流域梯级水电站多年平均来水条件下梯级联合调度为例对模型算法进行了验证分析。结果表明,基于改进NSGA-Ⅱ算法的梯级水电站多目标调度方法可以满足梯级水电站汛期防洪调度要求,同时梯级年发电量较常规调度图调度方式年发电量增加2.7%,更好地发挥了梯级水电站的综合效益。

In recent years,the suddenness,extremeness and abnormality of regional rainstorm and flood disasters have been significantly enhanced,and the uneven spatial and temporal distribution of runoff during the year has been further aggravated.The task of balancing flood control and benefit in the flood season dispatching of cascade hydropower stations has become an important research topic.In this paper,a solution method based on NSGA-Ⅱalgorithm is proposed to solve the problem of multi-objective joint dispatch of cascade hydropower station,which improves the population generation strategy and elite selection strategy of NSGA-Ⅱalgorithm.The flood control risk function was defined as the average flood control capacity occupancy of each station period,and the profit objective function was defined as the annual power generation of the cascade.The Pareto frontier analysis method was used to solve the joint scheduling problem of cascade hydropower stations with flood control and profit objective functions.Finally,the example of taking the joint operation of cascade hydropower stations under the condition of multi-year average inflow of cascade hydropower stations in a river basin verified the algorithm.The results show that the multi-objective scheduling method of cascade hydropower stations based on improved NSGA-Ⅱalgorithm can meet the requirements of flood control scheduling of cascade hydropower stations in flood season.The annual power generation of cascade hydropower stations is 2.7%higher than that of the common scheduling method.The comprehensive benefits of cascade hydropower stations have been better brought into play.