风光消纳对梯级水库群运行水位的影响

Impact of Wind and Solar Energy Consumption on the Operating Water Level of Cascade Reservoirs

水风光多能互补系统大多聚焦协同调度和提高新能源消纳研究,却忽略了风光能源消纳对水库水位的潜在影响。构建了考虑短期弃电特征的水风光互补系统中长期优化调度模型。首先,根据实际水风光出力模拟可能的弃电情景,拟合弃电损失函数,将其嵌套在中长期优化调度模型中;其次,模拟接入风光前后的水库调度运行过程;最后,分析风光消纳对梯级水库群年际、年内、月运行水位的影响。以黄河上游龙羊峡至刘家峡梯级水电站水风光互补系统为实例,研究表明:①接入风光后,梯级水库群的年均出力降低约0.5%,可促进风光消纳,保证系统总出力更大,可提高风光上网出力和系统总出力约2.2%;②风光消纳导致梯级水库群的年际和月水位波动增加,龙羊峡和刘家峡水库的年末消落水位和年均水位的波动范围分别增加2.5%、101.6%、0.8%和78.9%,龙羊峡的月水位波动变幅为0,刘家峡月水位下限降低14.7%;③在丰水年,接入风光后梯级水库水位显著下降;平水年,龙羊峡水库水位稍有降低,刘家峡水库的水位表现为汛前春季水位降低,汛后秋季水位升高;枯水年,风光消纳对水库水位几乎没有影响。这些研究结果对于更好地理解风光能源与水库运行之间的复杂关系以及优化水风光互补系统的运行策略具有重要的实际意义。

Researches on hydro-wind-solar hybrid energy systems have mostly focused on coordinated operation and enhancing the new ener⁃gy consumption but often overlooked the potential impact on the water levels of reservoirs.In this paper,a long-term optimal operation model for hydro-wind-solar hybrid energy systems,nested with short-term energy curtailment,is established.Firstly,the curtailment loss function was fitted based on actual hydro-wind-solar output data simulating potential curtailment scenarios,which was incorporated into a long-term optimal operation simulation;Secondly,simulations of the reservoir dispatching operation process before and after the integration of wind and solar energy were conducted;Finally,the impacts of wind and solar energy consumption on the annual,sub-annual,and monthly oper⁃ating water levels of the cascade reservoir group were analyzed.A case study was carried out using the hydro-wind-solar hybrid energy sys⁃tem from Longyangxia to Liujiaxia cascade reservoirs in the upper reaches of the Yellow River.The results show that:①After wind and solar energy integration,the annual average output of the cascade reservoirs decreases by approximately 0.5%to enhance the consumption of wind and solar energy,increasing the wind-solar power in grid and total system output by approximately 2.2%.②The wind and solar energy con⁃sumption leads to increased annual and monthly water level fluctuations in the cascade reservoir group.The end-of-year drawdown and annu⁃al average water level fluctuations ranges of Longyangxia and Liujiaxia reservoirs increase by 2.5%,101.6%,0.8%and 78.9%,respectively.Longyangxia experiences no change in monthly water level fluctuation,while Liujiaxia sees a reduction of 14.7%in the lower limit of monthly water levels.③In wet years,the wind and solar energy integration leads to a significant decrease in water levels of the cascade reservoirs.In normal years,Longyangxia reservoir experiences a slight decrease in water levels,while water level of Liujiaxia reservoir decreases in preflood spring and increases in post-flood autumn.In dry years,wind and solar energy consumption has almost no impact on reservoir water lev⁃els.These research findings hold significant practical implications for better understanding the complex relationship between wind and solar energy integration and reservoir operations and for optimizing the operational strategies of hydropower-wind-solar complementary systems.