水电站初期蓄水期下游梯级再调节优化策略研究——以叶巴滩–巴塘–苏洼龙梯级水电站为例

Optimization Strategy for Downstream Cascade Re-Regulation during the Initial Reservoir Impoundment Period—A Case Study of Yebatan-Batang-Suwalong Cascade Hydropower Stations

摘要: 水电站初期蓄水期间下闸蓄水会对下游来水过程造成剧烈影响，改变河道生态系统的稳定状态。本文以叶巴滩水电站初期蓄水为研究背景，构建叶巴滩–巴塘–苏洼龙梯级水电站协同优化调度模型，以修正全年流量偏差为目标，下游奔子栏水文站为考核断面，采用“参数化–模拟–优化”框架和自适应差分进化算法求解。结果表明：① 再调节优化策略为巴塘、苏洼龙梯级在10月27日和11月10日叶巴滩蓄水的两个时间节点后进行反调节，在叶巴滩水电站蓄至2845 m后需5 d的窗口期，利用来水回充库容并再次进行补偿调度。② 相对原方案，优化后奔子栏水文站断面多年平均AAPFD值降低了28.9%，缓解了叶巴滩水电站初期蓄水对下游流量的不利影响。③ AAPFD值和发电损失量相互制约，优化策略中巴塘、苏洼龙水电站调度期末可回蓄至正常蓄水位，不影响后续联合发电调度。

Abstract: During the reservoir preliminary impoundment period, gate closure for water storage significantly alters the natural flow regime downstream, destabilizing the ecological equilibrium of the riverine ecosystem. Focusing on the preliminary impoundment of the Yebatan reservoir, a coordinated optimal operation model for the Yebatan-Batang-Suwalong cascade hydropower system is developed in this study, aiming to minimize the Adjusted Annual Proportional Flow Deviation (AAPFD) value, with the Benzilan hydrological station downstream as the control section. The model uses a parameterization-simulation-optimization (PSO) framework integrated with an adaptive differential evolution algorithm. Results demonstrate that: 1) The re-regulation optimization strategy requires counter-regulation by the Batang and Suwalong cascade following the two Yebatan filling time nodes on October 27 and November 10. After the Yebatan reservoir reaches an elevation of 2845 m, a 5-day observation window is needed to replenish storage using incoming flows, followed by compensatory operation. 2) Compared with the original scheme, the optimization reduces the multi-year mean AAPFD value at the Benzilan control section by 28.9%, thereby mitigating the adverse impacts of the initial filling of the Yebatan Hydropower Station on downstream flows. 3) The AAPFD value and power generation losses exhibit a trade-off relationship. Under the optimized strategy, the Batang and Suwalong hydropower stations can refill to their normal storage levels by the end of the regulation period, unaffecting subsequent coordinated power generation operations.