Optimal guidance strategy for flexible load based on hybrid direct load control and time of use

The time-of-use(TOU)strategy can effectively improve the energy consumption mode of customers,reduce the peak-valley difference of load curve,and optimize the allocation of energy resources.This study presents an Optimal guidance mechanism of the flexible load based on strategies of direct load control and time-of-use.First,this study proposes a period partitioning model,which is based on a moving boundary technique with constraint factors,and the Dunn Validity Index(DVI)is used as the objective to solve the period partitioning.Second,a control strategy for the curtailable flexible load is investigated,and a TOU strategy is utilized for further modifying load curve.Third,a price demand response strategy for adjusting transferable load is proposed in this paper.Finally,through the case study analysis of typical daily flexible load curve,the efficiency and correctness of the proposed method and model are validated and proved.

SECOND-ORDER OPTIMALITY CONDITIONS FOR OPTIMAL CONTROL PROBLEMS GOVERNED BY 3-DIMENSIONAL NEVIER-STOKES EQUATIONS

This article is concerned with second-order necessary and sufficient optimality conditions for optimal control problems governed by 3-dimensional Navier-Stokes equations. The periodic state constraint is considered.

Energy-Efficient Optimal Guaranteed Cost Intermittent-Switch Control of a Direct Expansion Air Conditioning System

To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.

复杂工业过程控制中实时数据OPC Server的设计与研究

针对复杂工业过程控制的要求,研究了OPC Server的实时处理策略,完成了具有较高实时性和复用性的OPC Server的软件设计,体现了软件工程所追求的结构化设计与软件复用的思想。

梯级水库运行期设计洪水及水位联合优化调控变革与启示

我国水资源时空分布不均,年际、年内变差大,洪涝和干旱并存,流域防洪与兴利需求并重。随着大规模水库群建成投运,流域下垫面条件及产汇流机制明显变异,水库及引调水工程运行等人类活动对设计洪水影响显著,梯级水库群运行管理中如何分析和应用设计洪水成为亟待解决的新问题,水库群联合优化调控、水资源高效利用的现实要求十分迫切,已列入中国科学技术协会2023年十大产业技术问题。经过多年探索实践,我国在梯级水库运行期设计洪水及水位联合优化调控方面已取得一定研究进展和成果,但仍存在对暴雨洪水季节性变化规律认识不足、梯级水库群系统中各水库运行相互影响考虑不足、现代水文气象实时预报信息运用不足等问题,亟须系统开展运行期设计洪水及水位联合优化调控体系研究,实现风险可控条件下水资源高效利用,保障防洪安全、供水安全、能源安全、生态安全,推进新阶段经济社会高质量发展。

基于OPC通信技术的微电网优化监控系统研究

通过构建微电网多目标优化调度模型和设计改进型粒子群多目标优化算法,以实现微电网的节能减排优化运行;并在开发微电网优化监控系统过程中,基于OPC数据交换通信技术,集成了组态王专业的监控平台开发能力和MATLAB强大的科学运算能力,实现了组态王和MATLAB的优势互补,为微电网优化监控系统的开发提供了灵活高效的途径。

自循环发酵过程周期性开关操控的设计和分析

针对乙醇间歇发酵生产速率低、劳动强度大,连续发酵会带来基质损失,甚至可能导致系统失稳的问题,探讨了一种能自动进行周期开关操控的自循环发酵(SCF)方案,并期望通过理论分析与设计来提高发酵过程的生产强度,同时消除产物抑制诱导系统失稳。具体地,从连续发酵模型稳定性分析出发,借助最优周期控制(OPC)理论给出SCF强化生产速率的必要性判据;进一步研究发现乙醇产物抑制作用会导致连续发酵系统失稳,并可有效缓解产物抑制作用,消除产物诱导失稳问题。模拟结果表明,生物乙醇的SCF生产模式可以缩短批次发酵时间、避免系统失稳。

具有尺度结构的三竞争周期种群系统的最优边界控制

研究了在周期环境下,基于尺度结构和加权总规模的3种群非线性竞争系统的最优边界控制问题.由Mazur定理证明了最优边界控制的存在性,得到了由积分-偏微分方程和变分不等式组成的最优性组,给出了控制为最优的必要条件.

基于多源异构数据的能源电力碳排放监测诊断服务系统研究

针对我国碳排放工业类型多、碳排放监测数据源多样的问题,设计了一个基于多源异构数据的能源电力碳排放监测诊断服务系统。系统由非分光红外探测技术、改进型微分粒子群算法(particle swarm optimization,PSO)、云计算、对象链接与嵌入统一架构(OLE for process control-unified architecture,OPC-UA)技术等构成。通过改进PSO算法来提高收敛速度,进一步提高数据监测和处理效率。采取OPC-UA技术实现对碳排放多源异构数据进行统一传输和反馈,极大地缓解了系统主机的计算压力。试验结果表明,经系统技术核算的数据误差率在可接受范围内,为其他技术研究奠定基础。

渤海油田过筛管压裂井防砂有效期延长工艺研究

渤海油田低产低效油井具有较大的开发潜能,常规增注、酸化等措施均不能有效释放油井产能,致使增油效果不佳。近年实施的过筛管压裂工艺将解堵、增产、防砂作用有机结合,为达到延长过筛管压裂井防砂有效期的目的,进一步优化升级过筛管压裂工艺,并在现场应用。结果表明,增产效果良好,流压上升明显,采液指数大幅增加,且生产过程中未见出砂,防砂有效期超过60个月。

烧结过程优化控制中的OPC同步通信机制

以某钢铁企业烧结过程优化控制系统为对象,针对系统通信数据量大,时变性强的特点,通过分析控制系统结构和OPC同步通讯机制,利用分布式结构DCOM实现OPC客户应用与服务器的接口,构建了烧结过程优化控制应用软件和烧结DCS之间的高速数据通道,有效地解决了钢铁公司烧结过程优化控制应用软件与烧结DCS之间通信难的问题,达到了实时优化控制的目的。

MATLAB与EDPF-NT+系统OPC通讯实现及应用

EDPF-NT+系统OPC软件包通过系统专有的NETASK接口从MMI的虚拟DPU中读取实时数据,并将从OPC客户端读取的数据封装为MODBUS数据包,以MODBUS从站方式传送至虚拟DPU。利用系统的OPC软件包及MATLAB的OPC工具箱,能很方便地实现MATLAB与EDPF-NT+系统的双向实时通讯。本文还介绍了利用这种方法进行系统先进过程控制策略优化算法研究的应用实例。

Improvement of Camera Calibration Accuracy Based on Periodic Arrangement Characteristics of Calibration Target Pattern

Conventional camera calibration that employs calibration targets is a commonly used method to acquire a camera’s intrinsic and/or extrinsic parameters. The calibration targets are usually designed as periodic arrays of simple high-contrast patterns that provide highly accurate world coordinate system points and the corresponding image pixel coordinate system points. The existing pixel coordinate extraction algorithms can reach a sub-pixel level; however, they treat each single pattern in one image as an independent individual, which makes it difficult to further improve extraction accuracy. In this paper, a novel method is proposed by utilizing the periodic arrangement characteristics of the calibration target pattern as a global constraint to improve the calibration accuracy. Based on a camera’s pinhole model, the intersection point of two fitted curves is used as an optimized pixel point to replace the initial one. Following the pixel coordinate optimization procedures, experiments were performed using real data from a 3D laser line scanner and a dynamic precision calibration target. Our results show that the relative errors of camera homography matrix elements obtained by the proposed optimization method were reduced compared with the commonly used method. The average coordinate measurement accuracy can be improved by nearly 0.05 mm. It is shown that the proposed optimization method can enhance the camera calibration accuracy, especially when the extracted pixels are of poorer precision. © 2017 Tianjin University and Springer-Verlag Berlin Heidelberg

含高渗透新能源电力系统中考虑变时段控制的火/储/荷日前优化调度

新能源高渗透电力系统中以风电、光伏为代表的新能源具有的不确定性,使得火电机组难以满足调度计划的精度需求。为提高火电机组调度计划的准确性,提出考虑变时段控制的新能源高渗透电力系统中火/储/荷日前优化调度策略:首先使用高斯混合模型将净负荷按时序特性聚类成3种时段类型,然后按各时段特点设计火-储-荷的变时段控制规则以优化日前调度,利用需求响应优化抽水蓄能电站利用率;其次以系统总成本最小为目标,综合考虑所提策略形成的各类型机组约束建立火-储-荷调度模型,形成火-储-荷的日前调度计划;最后通过算例分析验证所提策略的有效性。

基于线性依赖的竞争系统脉冲控制与优化

本文针对两种群竞争系统中劣势种群趋于灭绝问题,通过监测两种群的数量制定基于线性依赖反馈的控制策略,建立一类具有线性依赖反馈控制的两种群竞争模型.首先,利用后继函数方法证明系统阶1周期解的存在唯一性,同时借助于类庞加莱准则,给出了阶1周期解稳定的充分条件;其次,结合实际情况构造了反馈控制最优化问题,获得了反馈控制及控制参数的最佳设定值.最后,利用MATLAB进行数值模拟,仿真结果进一步验证了本文结论的正确性以及控制策略的可行性.

The relationship between controllability, optimal testing resource allocation, and incubation-latent period mismatch as revealed by COVID-19

The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategies for controlling novel disease epidemics.To address the challenge of constrained resource optimization for managing diseases with complications like pre-and asymptomatic transmission,we develop an integro partial differential equation compartmental disease model which incorporates realistic latent,incubation,and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals.Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission.To analyze the influence of these realistic features on disease controllability,we find optimal strategies for reducing total infection sizes that allocate limited testing resources between‘clinical’testing,which targets symptomatic individuals,and‘non-clinical’testing,which targets non-symptomatic individuals.We apply our model not only to the original,delta,and omicron COVID-19 variants,but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions,which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness.We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies,while the relationship between incubation-latent mismatch,controllability,and optimal strategies is complicated.In particular,though greater degrees of presymptomatic transmission reduce disease controllability,they may increase or decrease the role of nonclinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length.Importantly,our model allows a spectrum of diseases to be compared within a consistent framework such that lessons learned from COVID-19 can be transferred to resource constrained scenarios in future emerging epidemics and analyzed for optimality.

用于直升机舱内降噪的智能周期撑杆研究

直升机主减速器内的齿轮啮合引起的中高频振动是直升机舱内噪声的主要来源之一,通过设计具有隔振性能的减速器撑杆可以有效抑制传递到机体的振动,进而减小齿轮啮合诱发的舱内噪声。基于压电叠堆/橡胶周期结构,提出了一种适用于直升机舱内降噪的主动/被动混合振动控制的智能周期撑杆,在满足强度与刚度要求的同时,具有优良的多频与宽频减振能力。压电叠堆与橡胶材料周期排列组成周期结构,其在特定频率范围内具有“机械滤波”特性;同时,通过调节驱动压电叠堆的电压与电流,改变压电叠堆的动刚度,可实现主动减振的功能。为了对智能周期撑杆的主动/被动混合振动控制性能进行分析,建立了基于传递矩阵形式的智能周期撑杆的机电耦合动力学模型,并使用多物理场仿真软件验证了模型的正确性。进一步基于该模型分析了在驱动电压与电流有限的条件下的智能周期撑杆的最优隔振性能:在智能周期撑杆一端固支、一端受到10N的激振力时,最大驱动电压为20V、最大驱动电流为1A的电学边界限制下,该智能周期撑杆具有将692Hz以上的振动完全衰减的能力,对692Hz以下的振动有一定程度的控制效果。此外,还研究了材料参数与力学边界条件对主动控制的影响,即橡胶材料的阻尼、激振力对进行主动控制时需要的驱动电压与电流的影响。使用有限元模型校核了智能周期撑杆的强度与刚度,验证了所提出的智能周期撑杆方案的工程可行性。使用压电叠堆作动器与聚酯乙烯杆件组成一个三周期的压电叠堆周期撑杆作为智能周期撑杆的简化模型,验证了主动/被动混合振动控制性能,分析了力学边界条件对隔振性能的影响,以及进行主动控制时的驱动电压和电流与最优驱动电压和电流的关系。

防污染漏失管柱优化应用

王集油田开发过程中存在高含蜡率(6.8%~34.53%)、蜡凝固点高(31℃~38℃)及由于采油作业过程中洗井液不配套、生产管柱不能洗井等原因造成油井析蜡问题严重,已严重影响油井的正常生产,且洗井周期短、排水期长;油井洗井作业后,油井恢复时间长,产量明显降低。针对该问题急需对目前的清防蜡工艺进行优化,开展王集油田防污染漏失管柱优化的研究。通过设计大通径Y221-115封隔器、Y445-115封隔器+偏心进油阀+尾管+丝堵的管柱组合优化设计,解决了油井清蜡漏失排水期长的问题,延长了管柱寿命,也解决了维护作业、洗井作业地层漏失的问题。通过现场试验,证明了防污染漏失管柱优化设计的合理性和可靠性,有效地解决了王集油田现有防污染漏失管柱的不足。

Harmonic balance-based approach for optimal time delay to control unstable periodic orbits of chaotic systems

As a classical technique for chaos suppression,the time-delayed feedback controlling strategy has been widely developed by stabilizing unstable periodic orbits(UPOs)embedded in chaotic systems.A critical issue for achieving high controlling precision is to search for an appropriate time delay.This paper proposes a simple yet effective approach,based on incremental harmonic balance method,to determine the optimal time delay in the delayed feedback controller.The time delay is adjusted within the iterative scheme provided by the proposed method,and finally converges to the period of the target UPO.As long as the optimal time delay is fixed,moreover,the attained solution makes it quite convenient to analyze its stability according to the Floquet theory,which further provides the effective interval of the feedback gain.

基于多级前馈与周期梯度寻优的烧结混合料水分控制方法

烧结混合料水分控制是烧结矿生产过程中十分重要的环节,其主要存在大滞后、多变量干扰及数据波动等控制难点。本文通过分析烧结混合料加水混合工艺与特点,针对一、二次混合制粒不同的工况条件,提出多级前馈联合周期梯度寻优控制策略,同时结合当前配料成分与透气性指数等关键参数,采用BP神经网络模型预测适合当前烧结的最优水分率,并从连续生产的角度识别停机、开车与模式切换等运行状态,最终替代人工控制实现加水混合全过程自动化。仿真结果和工业应用表明,本文提出的控制方法的性能优于常规PID控制,系统投运后能显著提升烧结自动化水平。