含多分水口的渠道广义积分时滞(ID)控制建模及验证

积分时滞（ID）模型是应用最广泛的输水明渠控制模型之一,建模时常假定分水口均位于渠池的下游尾端。然而对于我国灌区渠系而言,分水口位置可能位于渠池沿线任意位置,此时直接应用ID模型将会导致控制效果较差甚至出现系统失稳的可能。针对这种情况,本文首先分析了分水口位置对ID模型预测精度的影响,在考虑分水扰动的滞后时间后提出了广义ID模型,并分别以传统ID模型和广义ID模型为基础进行模型预测控制（MPC）算法开发及仿真验证。仿真结果显示,对于分水口位于上游段的渠池,本文所提出的广义ID模型预测精度更高,且控制效果的改善程度可达65%。同时在控制器调试过程中,控制器参数的可选域增大约1.4倍,表明更容易获取合适的控制器,试错成本显著降低。     

基于USB的水工模型流量与水位控制系统研究

在水工物理模型试验中，为了克服水工物理模型自控系统存在硬件集成度较低、兼容性与可拓展性不足的缺点，通过对自动控制系统流量、水位控制需求的分析，提出对流量、水位控制子系统进行模块化设计的思路。在“当前”水位与“目标”水位之间设置中间值，优化了水位控制原理，模拟了水位的缓变过程，优化了对尾门的控制。基于USB总线技术，利用Labview软件开发了硬件集成度高、灵活性强、兼容性好的可视化虚拟自动控制系统。系统已成功应用于多个非恒定流模型中，可使模型的水位、流量控制精度达到98%，超调量不超过5%。系统可在水工、河工模型的非恒定流试验中推广使用。     

基于改进模型预测控制的分布式储能辅助调频控制方法

为更好改善电网频率特性，发挥分布式储能的快速响应优势，提出基于改进模型预测控制的分布式储能辅助调频控制方法。首先，基于动态矩阵控制(dynamic matrix predictive control, DMC)思想，引入了一种新的综合状态空间模型，将增量控制输入视为阶跃输入，设计了以减小稳态误差为目标的MPC优化目标函数。其次，建立了控制信号的选择规则，在预测模型的滚动优化过程中对多步控制信号进行动态调整，形成考虑延时和丢包的延迟补偿机制，并在此基础上给出了系统稳定的充分条件。最后，在不同工况下进行仿真，与基于传统MPC的储能辅助调频方法相比，对所提策略的有效性进行了验证。结果表明：本文提出的改进MPC策略提高了分布式储能调频对通信延时的鲁棒性，提高电力系统的安全性，同时减小了系统超调量和稳态偏差。     

黄河调水调沙对三义寨灌区引水的影响及其对策

本文根据黄河调水调沙前后对该灌区渠首闸引水的影响,利用水力学计算出灌区渠首闸闸前水位与可引流量并绘制出闸前水位与可引流量关系曲线,结合灌区实测资料和灌区规划设计情况分析,查找黄河调水调沙对灌区引水影响的原因,从而针对影响提出应采取的对策。     

黄河调水调沙后大功灌区红旗闸现状引水能力分析

根据黄河调水调沙后大功灌区红旗闸前黄河来水及红旗闸实际引水资料,建立了红旗闸前黄河流量与水位、红旗闸引水流量与闸前水位关系式,并在红旗闸前黄河枯水流量及含沙量分析基础上确定了红旗闸正常可引水时间,最终提出了红旗闸现状年均可引水量。结果表明黄河调水调沙后大功灌区红旗闸引水能力远不及设计能力。但灌区引黄水资源量与取水许可量相比,尚有富余,可加大引黄力度。     

基于线性预测控制算法的明渠实时控制研究

针对纵坡较缓、渠池槽蓄量大且完全处于回水区的大型串联渠池中的水位控制问题,本文以南水北调中线工程最后6级渠池为研究对象,通过建立多级串联渠道的离散线性状态空间方程,设计用于多级串联渠池的线性预测控制算法,并采用低通滤波器对控制算法中需要用到的实时水位观测信息进行处理。研究结果表明采用低通滤波处理后的水位信息进行实时控制时能够消除没有明显回水区渠池中发生的水位波动,达到稳定控制的效果。在分水不可预知情况,预测控制算法起到集中反馈控制的效果,控制效果与线性二次型最优控制的控制效果类似;而在分水可预知情况,预测控制算法能提前于分水变化进行闸门控制,起到前馈控制的作用,进一步优化控制效果。     

基于相关向量机的调水工程调蓄水位预测模型

调蓄水位与其影响因素之间存在着复杂的非线性关系,针对BP神经网络模型的局限性,选取泵站开启时间差、起调水位、入流量、出流量作为主要影响因素,建立一种基于相关向量机(relevance vector machine, RVM)的调水工程调蓄水位预测模型。通过实例应用表明在相同样本情况下与BP神经网络模型预测结果相比,RVM预测模型均方根误差和平均绝对误差均小于BP神经网络预测模型的预测结果,说明在调水工程调蓄水位的预测中,RVM预测模型具有精度高、离散性小等优点,为调水工程调蓄水位的预测提供了一条新途径。     

华北典型灌区气候变化条件下地下水响应研究

基于MODFLOW模型,以华北平原人民胜利渠灌区为例,结合研究区水文地质条件,建立地下水运动数值模拟模型,通过参数校准和模型验证,表明建立的地下水运动模型能够合理地反映研究区2012-2013年的地下水运动状况,模拟结果表明该灌区地下水处于负均衡状态。基于模拟结果,进一步预测了气候情景(选取RCP4.5情景NorESM1-M模式)下灌区2030年地下水水位情况。结果表明与1997-2013年相比,2030年灌区地下水位持续下降,漏斗面积逐渐扩大。以此为基础,开展地下水开采量情景分析,将开采量分别增加和减少20%,预测2030年在不同开采量情景下地下水水位变化情况。最后根据预测结果初步提出地下水开采量减少20%的调控方案,以保证地下水水位有所上升,漏斗面积减少。     

基于水位与符号回归的灌区无干扰量水技术研究

为克服传统量水方法水头损失大、技术复杂、经济成本高等问题,提出了一种基于水位和符号回归的灌区无干扰量水方法,并依据高邮灌区典型斗渠2012～2013年实测水位流量数据,对方法应用效果进行了评估。结果表明:符号回归优选出来的5组模型均能较好地估算渠道流量,模拟值与实测值均方根误差RMSE和平均绝对误差MAE分别为71.81～73.43,52.15～56.38m~3/h,调整决定系数超过0.8,说明模型能够较好地反映渠道水位流量关系,模拟精度较高。该方法精度可靠、应用简便、经济可行,在灌区量水方面具有较广的应用前景。     

基于单神经元PID控制器在渠道自动控制中的应用

将基于单神经元自适应PID控制器引入到渠道系统自动控制中,它实现了PID控制中参数整定不依赖于渠道数学模型,且能在线依据渠道系统的动态信息调整PID参数,以满足适时控制的要求.通过Matlab软件的仿真,结果表明:采用基于单神经元自适应PID控制器,渠道运行响应加快,水位超调变小,适应性增强,且有更好的动态和稳态性能.     

Multiple Model Predictive Flood Control in Regulated River Systems with Uncertain Inflows

This paper presents a novel approach to real time automatic flood control in a managed river network that is subject to uncertain inflows. The proposed approach uses multiple models to represent inflows ranging from low to high flow. Optimal model selection is achieved in a minimum mean square error sense using a bank of Kalman filters to identify the most likely inflow characteristic. There are no a-priori probabilities assigned to the individual models. Model Predictive Control is used for water level controller design. Our Adaptive Multi Model Predictive Control (AMMPC) method is proposed as an alternative to existing techniques that also use multiple inflow models but with a-priori inflow model probabilities, either weighted or equally likely. The performance of the approach is demonstrated using a simulated river-reservoir model as well as using data collected at the Wivenhoe Dam during the 2011 floods in Queensland, Australia.     

Comparative Application of Model Predictive Control and Particle Swarm Optimization in Optimum Operation of a Large-Scale Water Transfer System

Water Resources Management - This research evaluates the application and performance of two methods of Model Predictive Control (MPC) and Particle Swarm Optimization (PSO) in real time control and...     

长距离明渠调水工程蓄量动态调节控制算法研究

本文阐明了明渠渠池蓄量与节制闸闸前水位之间的单值对应关系,在此基础上提出一套通过动态调节渠池蓄量,实现闸前常水位运行的控制算法。该算法基于流量平衡和蓄量平衡关系推导,前馈控制与反馈控制相结合。前馈控制根据分水口计划主动调节各渠池蓄量,起粗调作用;反馈控制针对前馈控制过程出现的水位偏差,通过动态调节各渠池蓄量实时校正,起细调作用。该算法具有原理简单,参数率定简便,控制规则灵活,实用性强等特点。算法在南水北调东线工程胶东段渠道进行了仿真测试,模拟环境包含水位死区和闸门运动死区。结果表明,所提算法能够有效克服长距离明渠水力滞后的影响,及时有效消除各渠池闸前水位偏差,将水位波动限定在安全范围内。     

Modeling Multi-objective Pareto-optimal Reservoir Operation Policies Using State-of-the-art Modeling Techniques

A novel challenge faced by water scientists and water managers today is the efficient management of the available water resources for meeting crucial demands such as drinking water supply, irrigation and hydro-power generation. Optimal operation of reservoirs is of paramount importance for better management of scarce water resources under competing multiple demands such as irrigation, water supply etc., with decreasing reliability of these systems under climate change. This study compares six different state-of-the-art modeling techniques namely; Deterministic Dynamic Programming (DDP), Stochastic Dynamic Programming (SDP), Implicit Stochastic Optimization (ISO), Fitted Q-Iteration (FQI), Sampling Stochastic Dynamic Programming (SSDP), and Model Predictive Control (MPC), in developing pareto-optimal reservoir operation solutions considering two competing operational objectives of irrigation and flood control for the Pong reservoir located in Beas River, India. Set of pareto-optimal (approximate) solutions were derived using the above-mentioned six methods based on different convex combinations of the two objectives and finally the performances of the resulting sets of pareto-optimal solutions were compared. Additionally, key reservoir performance indices including resilience, reliability, vulnerability and sustainability were estimated to study the performance of the current operation of the reservoir. Modeling results indicate that the optimal-operational solution developed by DDP attains the best performance followed by the MPC and FQI. The performance of the Pong reservoir operation assessed by comparing different performance indices suggests that there is high vulnerability (~?0.65) and low resilience (~?0.10) in current operations and the development of pareto-optimal operation solutions using multiple state-of-the-art modeling techniques might be crucial for making better reservoir operation decisions.

     

渠首水位实时调控模型——以船行灌区一支渠为例

很多大中型灌区在输配水过程中存在水位衔接不当的问题,加之田面高程存在起伏,使得灌溉时往往存在部分田面不能上水或受淹等问题。本文提出了空间灌溉率的概念,并利用GIS的三维分析功能研究了其与渠道渠首水位之间的关系。分析表明,空间灌溉率与渠首水位之间的关系符合Logistic曲线;针对船行灌区一支渠,得到该Logistic曲线的参数,并确定了一支渠渠首和干渠渠首不同空间灌溉率所需的水位,为灌区水位实时调控提供基础数据。     

Predictive control of irrigation canals – robust design and real-time implementation

Predictive control is one of the most commonly used control methods in a variety of application areas, including hydraulic processes such as water distribution canals for irrigation. This article presents the design and application of predictive control for the water discharge entering into an irrigation canal located in Spain. First, a discrete time linear model of the process is described and its parameters are experimentally identified. The model is well validated within the usual canal operating range and is used to formulate a predictive control law with an incremental formulation. Finally, experimental and simulation results are presented in which predictive control has shown better performance than a well-tuned proportional, integral and derivative controller to automatically manage demanded water discharges.     

基于空间分布的灌区灌溉水利用系数计算方法分析

采用经验公式法和实测拟合法分别计算了河南省人民胜利渠灌区渠道单公里渗漏量,以斗渠为控制单元,分不同方案自下而上计算不同级别渠道渗漏损失和推算渠首流量。采用多元线性回归的方法分析计算基于空间分布的灌区灌溉水利用系数,并得出了适于该灌区灌溉水利用系数空间分布的计算方法,为分析计算灌区不同斗渠控制单元灌溉水量向渠首灌溉水量的转换提供技术手段和科技支撑。     

Short Term Optimal Operation of Water Supply Reservoir under Flood Control Stress using Model Predictive Control

Reservoir operations require enhanced operating procedures for water systems under stress attributed to growing water demand and consequences of changing hydro-climatic conditions. This study focuses on the management of the Yuvacik Dam Reservoir for water supply and flood mitigation in the Marmara Region of Turkey. We present an improved operating technique for fulfilling the conflicting water supply and flood mitigation objectives. This is accomplished by incorporating the long term water supply objectives into a Guide Curve (GC) whereas the extreme floods are attenuated by means of short-term optimization based on Model Predictive Control (MPC). The reference case implements operating rules with a constant GC at maximum forebay elevation targeting the fulfillment of the water supply objective. We compare the reference with a new time-dependent GC, derived using an Implicit Stochastic Optimization (ISO) approach. This new curve shows nearly the same performance regarding the water supply objectives, but significantly reduces the flooding risk downstream of the dam. Possible flood events observed at the end of the wet season, when the reservoir is at the maximum level to enable water supply for the dry season, can be eliminated by the application of an additional short-term optimization by MPC. The robustness of the approach is demonstrated via hindcasting experiments.