长距离输水渠道冰期运行控制研究

高纬度地区的渠道在冬季往往采用冰盖下输水，保证冰盖的稳定性是渠道冬季安全输水的前提条件。目前，渠道在冬季的运行控制多依靠经验，开展长距离渠道冰期运行控制研究对实现冰期安全输水是十分重要的。利用数值模拟的方法分析了长距离输水渠道的冰情和水情的变化过程，根据渠道内的冰情演变特性，提出冬季渠道应采用闸前常水位方式运行。鉴于气象预报以及冰情预报可能存在的不确定性，提出采用水位-流量串级的反馈控制算法，建立了渠道冰期运行控制模型，并在控制器内加入解耦环节，以提高渠道的控制效果。并通过南水北调中线干渠的数值模拟实验，对渠道冰期运行控制模型的控制效果进行了验证。结果表明，该冰期运行控制模型可以实现渠道冬季安全、适时、适量的供水目标。

Operation and Control to Long Distance Water Diversion Canal System during Frozen Period

The canal systems in high latitude area are usually operated under ice cover during winter. Maintaining the ice cover stability is the prerequisite for water diversion during winter. At present hydraulic control to long distance water diversion canal system during winter almost depends on only operators' experience. Therefore, it is very important to study control mode for safe operation of the long distance water diversion canal system under ice cover. Ice and hydraulics process in the canal system during winter was studied by means of numerical simulation. And the canal system should be operated under constant downstream depth according to the characteristics of the freezing process. Considering that weather and freezing process are hardly to forecast correctly, a proper feedback control method, that is water level-discharge cascade control algorithm, is adopted to control the water diversion canal system during winter, and a decoupling method is also applied in the controller for improving the control performance of the canal system. This new control algorithm is applied in the Middle Route of the South-to-North Water Transfer Project in China, and the numerical simulation results shows that the hydraulic control mode for the canal system under ice cover can guarantee safe, timely and proper water diversion.