Multi-Time Scale Operation and Simulation Strategy of the Park Based on Model Predictive Control

Due to the impact of source-load prediction power errors and uncertainties,the actual operation of the park will have a wide range of fluctuations compared with the expected state,resulting in its inability to achieve the expected economy.This paper constructs an operating simulation model of the park power grid operation considering demand response and proposes a multi-time scale operating simulation method that combines day-ahead optimization and model predictive control(MPC).In the day-ahead stage,an operating simulation plan that comprehensively considers the user’s side comfort and operating costs is proposed with a long-term time scale of 15 min.In order to cope with power fluctuations of photovoltaic,wind turbine and conventional load,MPC is used to track and roll correct the day-ahead operating simulation plan in the intra-day stage to meet the actual operating operation status of the park.Finally,the validity and economy of the operating simulation strategy are verified through the analysis of arithmetic examples.

System dynamics model of the support-surrounding rock system in fully mechanized mining with large mining height face and its application

Fully mechanized mining with large mining height(FMMLMH)is widely used in thick coal seam mining face for its higher recovery ratio,especially where the thickness is less than 7.0 m.However,because of the great mining height and intense rock pressure,the coal wall rib spalling,roof falling and the instability of support occur more likely in FMMLMH working face,and the above three types of disasters interact with each other with complicated relationships.In order to get the relationship between each two of coal wall,roof,floor and support,and reduce the occurrence probability of the three types of disasters,we established the system dynamics(SD)model of the support-surrounding rock system which is composed of"coal wall-roof-floor-support"(CW-R-F-S)in a FMMLMH working face based on the condition of No.15104 working face in Sijiazhuang coal mine.With the software of Vensim,we also simulated the interaction process between each two factors of roof,floor,coal wall and the support.The results show that the SD model of"CW-R-F-S"system can reveal the complicated and interactive relationship clearly between the support and surrounding rock in the FMMLMH working face.By increasing the advancing speed of working face,the support resistance or the length of support guard,or by decreasing the tipto-face distance,the stability of"CW-R-F-S"system will be higher and the happening probability of the disasters such as coal wall rib spalling,roof falling or the instability of support will be lower.These research findings have been testified in field application in No.15104 working face,which can provide a new approach for researching the interaction relationship of support and surrounding rock.

Coordinated Control Architecture for Motion Management in ADAS Systems

Advanced driver assistance systems(ADAS) seek to provide drivers and passengers of automotive vehicles increased safety and comfort. Original equipment manufacturers are integrating and developing systems for distance keeping, lane keeping and changing and other functionalities. The modern automobile is a complex system of systems. How the functionalities of advanced driver assistance are implemented and coordinated across the systems of the vehicle is generally not made available to the wider research community by the developers and manufactures. This paper seeks to begin filling this gap by assembling open source physics models of the vehicle dynamics and ADAS command models. Additionally, in order to facilitate ADAS development and testing without having access to the details of ADAS, a coordinated control architecture for motion management is also proposed for distributing ADAS motion control commands over vehicle systems. The architecture is demonstrated in a case study where motion is coordinated between the steering and the braking systems, which are typically used only for a single functionality. The integrated vehicle and system dynamics using the coordinated control architecture are simulated for various driving tasks. It is seen that improved trajectory following can be achieved by the proposed coordinated control architecture. The models, simulations and control architecture are made available for open access.

Automatic control strategy for step feed anoxic/aerobic biological nitrogen removal process

Control of sludge age and mixed liquid suspended solids concentration in the activated sludge process is critical for ensuring effective wastewater treatment. A nonlinear dynamic model for a step-feed activated sludge process was developed in this study. The system is based on the control of the sludge age and mixed liquor suspended solids in the aerator of last stage by adjusting the sludge recycle and wastage flow rates respectively. The simulation results showed that the sludge age remained nearly constant at a value of 16 d in the variation of the influent characteristics. The mixed liquor suspended solids in the aerator of last stage were also maintained to a desired value of 2500 g/m3 by adjusting wastage flow rates.

Considering Process Nonlinearity in Dual-Point Composition Control of a High-Purity Ideal Heat Integrated Distillation Column

Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.

STUDY ON SIMULATION EXPERIMENT OF EQUIVALENT MATERIAL APPLIED IN COAL MINE

Based on simulation experiments of a number of scientific research items, the latest progress of experiment method and test technique about equivalent material simulation are introduced. The bevelopment of experiment technique makes analogy simulation evolve into quantitative research about support-surrounding rock relationship from qualitative experiment.From this, large scale stereoscopic simulation experiment is developed, which has never appeared in underground pressure research in China. The present mold specification is 3 - 6 m×2. 0 m ×1. 5 m.

地铁站深基坑稳定性监测与数值模拟分析

为研究深基坑开挖对支护结构与周边环境的影响,以合肥要素大市场地铁站为研究背景,采用数值模拟、物理模拟与现场监测的方法,分析了深基坑围护结构、内支撑与周边地表沉降规律。结果表明:随着基坑向下开挖,围护结构水平位移逐渐呈现出“弓形”的变化规律,在地表以下15 m处达到最大值22.3 mm;基坑周边地表的沉降值呈现出“勺形”的变化规律,其沉降峰值为15.4 mm,峰值点出现于距离基坑边缘12.5 m处;各层支撑轴力峰值在设计轴力的21%~58%,各指标的变化都在安全控制范围内;相似模型围护结构侧移量及土体变化规律与现场监测数值基本吻合,该车站深基坑的支护结构方案合理有效,可为合肥地铁站后续深基坑支护设计提供理论指导。

深埋软岩巷道围岩变形控制一体化支护技术

针对深埋软岩巷道围岩变形问题,提出深埋软岩巷道围岩变形控制一体化支护技术。首先分析了“让压—支护”围岩控制机理,进一步采用二次支护技术,通过注浆及联合支护完成一体化支护。在此基础上,利用FLAC数值模拟软件构建地质模型,获得深埋软岩巷道围岩垂直应力分布和水平应力分布,分析应用支护技术后对围岩变形位移量的控制。研究表明,利用一体化支护技术,可以有效地将深埋软岩巷道围岩变形控制在一定范围。

滚珠丝杠进给系统刚度建模及仿真

以数控机床为研究对象,建立滚珠丝杠进给系统动力学模型,并根据滚珠丝杠的安装方式,建立进给系统轴向刚度和扭转刚度模型。根据刚度对进给系统动态特性的影响,利用动态仿真工具MATLAB/Simulink建立包含刚度环节的进给系统仿真模型,获得了反映系统性能的仿真曲线。为减小刚度因素对系统性能的影响,提出控制补偿策略,仿真结果表明该策略提高了进给系统的稳定性和快速响应特性,减少了系统稳态误差。

大规模电力系统阻尼控制器协调优化方法

为提高电力系统的小干扰稳定性,研究了阻尼控制器之间的协调优化策略,以选定的待改善模式为目标模式,采用模式追踪技术,以目标模式阻尼比最大化为优化目标建立优化模型,采用一种基于云模型理论的改进模拟植物生长算法(plant growth simulation algorithm,PGSA)对阻尼控制器参数进行协调优化。该算法通过改进搜索步长和迭代中加入云模型理论来提高算法的搜索效率和收敛速度,并且克服了常规PGSA算法无法适用于连续函数优化的缺点。进一步,基于大规模电网算例,分别以局部和区域间的低频振荡模式为目标模式进行参数优化,仿真结果验证了所提方法的有效性。

延续性护理干预模式对促进母乳喂养的影响

目的:探究延续性护理干预模式对促进产妇母乳喂养的影响。方法:选取2015年1-12月本院收治的400例住院产妇作为研究对象,按出院日期的奇偶数顺序随机分为对照组和试验组,每组200例。对照组采取常规护理干预模式,试验组在对照组基础上采取延续性护理干预模式。比较两组母乳喂养自我效能量表(BSES)评分、社会支持评定量表(SSRS)评分及母乳喂养情况。结果:两组产后6周、6个月BSES和SSRS评分均高于产后3 d,且试验组高于对照组,比较差异均有统计学意义(P<0.05);试验组产后6周、6个月纯母乳喂养率均高于对照组,比较差异均有统计学意义(P<0.05)。结论:对产妇实施延续性护理干预,可在一定程度上提升母乳喂养率,值得大力推广。

电力系统全过程动态仿真中的机炉协调控制系统模型研究

机炉协调控制系统(coordinated control system,CCS)是火电机组满足电网负荷需求和保证机组本身稳定运行的重要控制措施。在分析机炉协调控制系统原理和控制方式的基础上,提出了一种适于电力系统机电暂态及中长期动态全过程仿真的机炉协调控制模型,并在电力系统全过程动态仿真程序进行编程实现。通过模型参数值的设置,该模型可以灵活模拟炉跟机、机跟炉、协调控制、直接能量平衡等火电厂机炉控制中的常见组态方式。采用两个仿真算例说明了不同CCS控制方式对机组功率的影响,以及CCS在与频率动态特性相关的电力系统动态仿真中的作用。

基于系统分割的保留非线性快速P-Q分解状态估计法

提出了一种新的状态估计算法,既保留了量测方程非线性又利用了快速P-Q分解方法,因此数学模型精度高且保留了快速P-Q分解的优点,提高了状态估计的计算精度和速度。采用系统分割方法将大系统分割为多个小系统,分别对每个小系统进行状态估计,然后对各小系统的状态估计结果进行协调,得到整个系统具有同一参考节点的状态估计结果,这样可大大提高状态估计的计算速度,有利于进行大电网的状态估计。在18节点系统上进行的数字仿真实验验证了该方法的有效性。

电力系统全过程动态仿真中的自动发电控制模型

针对大规模电力系统二次调频控制的动态仿真问题,采用混杂系统的建模方法,提出一种适于机电暂态及中长期动态全过程仿真的自动发电控制模型。模型主要由属于连续动态系统的区域控制偏差计算、属于离散动态系统的控制策略和机组调节指令计算3个模块组成。通过与电力系统全过程动态仿真程序中已有模型的接口,该模型可以模拟大规模电网中基于A标准和CPS控制性能评价标准的控制策略,以及定频率控制、定交换功率控制和联络线功率频率偏差控制等多种方式。与我国特高压交流联络线相关的2个算例仿真表明,该模型可为大规模电网联络线功率波动限制、多区域AGC控制策略的协调配合和二次调频的优化控制等实际电网问题提供有效的仿真手段。

基于控制原理和情感计算的信息推荐

在分布式合作信息推荐系统中 ,系统的目标是使信息尽量流动到需要该信息的用户手中 ,促进宏观信息的有效流动 ,这是一种有目的性的行为 ,可以抽象为复杂系统的控制问题 .由于系统的复杂性和动态性 ,集中式控制难以奏效 ,研究表明 :通过用户的局部 PI控制 ,可以获得很好的宏观控制质量 ,简单的控制规则可以在分布式信息推荐中产生很好的效果 .信息推荐需要基于用户的需求模型 ,鉴于基于符号空间建立用户需求模型存在的不足 ,给出了基于情感空间建立用户需求模型的方法 ,用户通过“很喜欢 ,喜欢 ,一般 ,不喜欢”等情感词汇表达自己的偏好 .仿真实验表明 :情感空间模型可以很好地表达用户的偏好 ,模糊化的局部 PI控制能够使计算机逐渐适应用户的需要 .

基于混合逻辑动态模型的混杂系统预测控制

针对过程工业控制对象的混杂特性 ,采用基于混合逻辑动态模型的预测控制策略。给出混杂系统的建模方法 ,并对其稳定性进行分析。仿真结果表明基于混合逻辑动态模型的预测控制能使混杂系统跟踪设定值并满足操作约束 。

带填充墙的新型梁柱-板柱组合结构振动台试验研究

对新型梁柱板柱组合结构体系的一个 9层 1∶1 5缩尺比例模型进行了振动台试验研究 .结合工程实际 ,试验模型中设置了填充墙 .试验结果表明 :该新型体系能够承受 7度烈度区的作用 ;填充墙的存在使得该体系的竖向刚度分布较为均匀 ,其变形和破坏形态有从框架型向剪力墙型转化的趋势 ;在底部 ,1阶振型占主导地位 .据此 。

前馈——模型参考自适应复合控制策略

由于多余力矩严重影响了电动负载模拟器的加载性能,提出了一种复合控制方法对该问题进行研究。首先考虑承载对象运动带来的干扰,建立了系统的数学模型;然后,针对控制系统单独采用前馈补偿或自适应控制方法的局限性,进行了基于前馈控制和模型参考自适应控制的复合控制系统设计,并利用Lyapunov函数的方法构造了自适应控制器。最后的仿真结果表明,采用复合控制方法能够大幅度消除电动负载模拟器的多余力矩,验证了控制策略的可行性。

助行康复机器人减重支撑单元控制仿真研究

目的:研究助行康复机器人减重支撑机构恒质量减重控制策略,为神经损伤患者运动过程下肢承受动态负荷的训练提供理论依据。方法:设计一种用于助行康复机器人的减重支撑机构,研究行走过程中人机系统的动力学特性,并提出了平衡身体重力及惯性力的恒质量减重控制策略。根据人体运动重心变化规律及机构参数,通过MATLAB软件对助行过程中恒质量减重控制进行了仿真研究。结果:仿真结果验证了在力闭环控制器的作用下,支撑机构能够跟踪人体的主动运动并对人体实现恒质量减重。结论:减重支撑机构适用于减重步行康复训练,恒质量减重控制策略为患者下肢承受动态负荷的训练提供了理论依据。

基于RBF核支持向量回归的模型预测控制仿真

RBF核函数的表达式较复杂,用于模型预测控制时滚动优化求解困难。该文建立一种基于RBF核SVR的预测控制模型,利用多智能体粒子群(MAPSO)算法求解模型预测控制中的滚动优化,推导出最优控制律,对其进行Matlab仿真并与其他方法进行比较。选取一个非线性系统及连续搅拌槽式反应器进行测试分析,结果表明:该预测模型能迅速抑制干扰,较快返回预设跟踪轨迹,展现了良好的抗噪、抗干扰能力。