关键词: 发电流量修正；水量平衡；出库流量；SCE-UA 算法；水轮机机组特性曲线；三峡水库；葛洲坝水库；梯级水电站

Abstract: The calculated total outflow from Gezhouba Reservoir substantially exceeds the discharge released by Three Gorges Reservoir. This volume discrepancy surpasses the natural inflow contribution from the inter-reservoir reach, necessitating immediate outflow recalibration. To accurately calculate outflow of Gezhouba Reservoir and maintain hydrological equilibrium between the Three Gorges-Gezhouba cascade reservoirs, we employed the SCE-UA optimization algorithm with the inflow-outflow water balance as the calibration criterion. Seasonally varying, head-dependent correction coefficients were developed to rectify turbine-specific discharge allocation. Our results demonstrated a reduction in mean absolute discharge deviation (MAD) from 1720 to 571 m3/s, with monthly volume deviations decreasing from 4.318 to 0.109billionm3. Corresponding non-flood season improvements showed MAD reduction from 1650 to 745 m3/s and volume deviation decreased from 452 to 253millionm3. The water balance-based discharge correction framework significantly enhanced outflow quantification accuracy, effectively mitigated systemic water balance errors, and provided reliable hydrologic data for cascade reservoir operations.

Key words: correction of power generation flow; water balance; outflow discharge; SCE-UA algorithm; characteristic curve of water turbine unit; Three Gorges Reservoir; Gezhouba Reservoir; cascade hydropower station