基于线性二次型的多级联输水渠道最优控制

灌溉输配水是水联网链路的重要环节，其自动控制水平直接影响着水联网效率和风险控制能力，对实现水资源高效管理与利用有重要意义。通过变化输水渠道线性积分时滞控制模型，建立了多级联渠道离散时间状态空间方程，基于线性二次型理论设计最优状态反馈控制器，利用MATLAB求解和SOBEK模拟进行了验证。在甘肃省昌马南灌区多级联渠道运行过程优化控制的模拟结果显示，线性二次型算法能够使控制点水位较快恢复并稳定在设定值，控制过程动作与水位波动次数少、幅度小，效果远优于常规分布式PI反馈控制。线性二次型算法能够应对多级联渠道时滞、耦合特性和一般未知取水扰动，实现可靠供水服务和有效运行控制。目前算法仅采用反馈控制，尚无法应对过大未知取水扰动，还有进一步改进空间。

Linear quadratic optimal control of multi-cascaded canals

Water delivery and distribution for irrigation through canals is the most important part of the internet of water (iWater). The automatic control level of this component directly affects the efficiency and risk control ability of the whole water supply system, and is of great significance for efficient management and utilization of water resources. By discretizing and transforming the integrator-delay model, discrete-time state-space model is formulated. Then optimal state-feedback controller is designed based on linear quadratic (LQ) theory and uses canal automation simulation software SOBEK along with MATLAB to test the proposed controller on the multi-cascaded canals of Changma South Irrigation District (CSID) in Gansu Province. The simulation results show that LQ optimal controller can effectively handle designed changes in water demand, stabilize the system in a reasonable time and steadily maintain the water level within the operational range, and thus the performance of the designed controller is much better than classic decentralized PI controller. In short, LQ optimal controller can effectively cope with time delays, coupling characteristics and unscheduled water intake disturbances inherent in multi-cascaded irrigation canals, and thus achieve reliable water supply service and efficient irrigation canals operation control. However, since LQ controller only uses feedback control logic, it cannot cope with excessively large unscheduled water intake disturbances effectively.