智能电网温度高精度远程在线控制方法研究与改进

摘要： 利用传统方法进行新型智能电网温度控制时,主要依靠建立的温度变化模型,但是新型智能电网系统具有时变性、不确定性、多扰动性等缺陷,很大程度上降低了温度变化模型的精度,导致传统方法不能对新型智能电网的温度进行准确控制。提出一种新的新型智能电网温度高精度实时控制改进方法:建立新型智能电网温度高精度实时控制系统与温度控制模型,并结合模糊免疫PID控制方法对新型智能电网温度进行高精度实时控制;针对智能电网的缺陷特征,依据灰色系统的理论进行改进,利用建立的灰色模型,对智能电网温度控制系统的灰量进行白化处理,将智能电网的缺陷特征作为灰色系统,通过灰色预测补偿控制技术对缺陷特征进行补偿控制,完成新型智能电网的温度高精度实时控制方法的改进。实验结果表明,与传统方法相比,改进的温度控制方法温度控制精度高,同时可改善弱温度控制过程中的振荡与超调问题。     

基于神经网络与遗传算法的大体积混凝土全过程智能通水模型

大体积混凝土的温度控制是避免结构出现温度裂缝的关键手段,为了实现施工全过程的温度控制,智能优选合适的冷却参数,结合有限元仿真计算,基于神经网络和遗传算法,以各冷却阶段的通水温度和通水流量作为输入,以温度演化过程中的控制温度(最高温度、一冷、中冷目标温度、灌浆温度)作为输出,建立了智能通水优化模型,并通过实例验证了模型的有效性。结果表明,由该模型得到的通水参数能满足设计及施工阶段的控温目标,模型可用于大体积混凝土全过程的温度控制。     

流体热物性测试用全自动高精度恒温槽的研制

为解决高精度流体热物性测试中的恒温环境问题 ,研制了一套高精度的恒温槽。恒温槽的温度控制系统采用准二维模糊控制器和 PID控制相结合的方法。同时 ,利用 C ++语言 ,在 Windows环境中实现了恒温槽温度控制和测量的全自动化。实验结果表明 :恒温槽的可控温度为室温至 2 5 0℃ ,波动度优于± 3 m K/1 5min,达到国外同类产品的水平 ,完全能够满足高精度流体热物性测试的需要     

适应于快速热处理设备的温度测量与控制系统设计

提出了一种适应于快速热处量设备(RTP)的温度测量与控制方法。介绍了快速热处理设备工作原理和主要关键技术;针对温度测量与温度控制两大关键技术,提出了先进的解决方案,即一种增强反射及发射率在线测量与补偿的温度测量方法和基于系统模型多输入多输出(MIMO)温度控制方法;通过实验验证了该温度测量方法和温度控制方法的可行性与先进性,并将该温度测量与温度控制系统应用于我们自主研发的快速热处理设备上,证明该温度测量与控制系统完全能满足设备的各项工艺指标。     

某F级重型燃气轮机启动过程仿真研究

基于MATLAB/SIMULINK仿真平台,采用模块化建模方法建立了重型燃气轮机非线性仿真模型以及启动过程中启动升速、转速/功率与压气机进口可转导叶开度(IGV)温度控制等关键控制器仿真模型。以某F级重型燃气轮机机组为研究对象,对设计工况与启动加载过程进行了仿真计算与分析,结果表明,所搭建的燃气轮机瞬态仿真模型不仅在设计工况下具有较好的仿真精度,还可以对燃气轮机启动过程进行较好的仿真模拟,在机组瞬态过程运行特性分析与预测,控制系统的调试与优化以及系统与设备的故障诊断等方面均具有实际的工程意义。     

基于前馈-自抗扰算法的换热器动态试验温度控制研究

为了使换热器试验测控系统满足动态换热试验中对温度控制的要求,分析了试验系统中被控温度对象动态模型,设计了前馈-自抗扰温度控制算法。动态换热试验对象为管壳式换热器,试验过程管程流体为强迫对流换热,壳程流体自然对流换热,同时管程流体循环利用,要求控制管程入口温度稳定。控制算法全面利用模型信息,将壳程温度作为管程温度控制中的干扰,为其设计前馈补偿,同时设计自抗扰控制算法,处理模型偏差问题。利用AMESim软件搭建系统模型,在Simulink中设计控制算法,进行了AMESim/Simulink联合仿真,通过对比多种控制算法,验证了在壳程温度变化干扰的换热过程中,使用前馈-自抗扰控制算法能够使管程入口温度波动更小,更快达到稳定。     

柴油机双层隔振系统刚度优化及试验分析

对必须考虑中间质量柔性效应的双层隔振系统,为解决有限元方法进行隔振器刚度优化工作量巨大、计算周期长的难题,提出了一种使用动力学方法进行隔振器刚度优化,根据优化结果采用有限元模型进行验证的优化方法,并最终结合试验对该方法进行有效性检验.根据双层隔振系统的结构参数,以不同的优化目标,编制双层隔振系统解耦优化程序,获得各隔振器刚度方案下的优化结果;利用优化结果,进行双层隔振系统有限元模型的强迫振动计算,计算机组的振动烈度和二级隔振器位置处的支反力总和,其与动力学方法的计算结果变化趋势一致.根据最优隔振器刚度方案,对柴油发电机组进行了台架运行试验.结果表明:有限元方法计算的机组的振动烈度和支反力之和与试验结果吻合很好,验证了该方法的正确性.     

火电厂主蒸汽温度UMDA整定模糊PID控制算法

针对火电厂锅炉主蒸汽对象的温度控制变参数、大时滞问题,提出了一种基于单变量分布估计优化算法(UMDA)整定的模糊PID控制算法,以改善温度控制效果.对于给出的大时滞系统模型,首先在PID控制器的基础上通过模糊控制规则并行地进行辅助修正,采用UMDA对其中参数进行整定,实现对模糊PID的自整定优化设置,最后对所设计的时滞温控系统进行仿真分析.结果表明:采用所提方法系统在无扰情况下基本不存在超调,摄动输入下也能明显地降低超调量,且调整时间较短,明显改善了原系统的动态性能和静态性能.     

基于调控一体自动化的变电站电气设备故障分析

电气设备是变电站发挥电力控制与管理功能的主要载体,电气设备故障监测是确保区域电力稳定运行的基础。文中构建了BP神经网络故障检测模型,利用调控一体自动化变电站的在线监测系统采集设备运行状态数据,将其作为故障检测样本;基于粒子群优化算法修正神经网络的权值与阈值,得到高精度的BP神经网络故障检测模型;将故障检测样本输入训练完成的模型中,输出电气设备故障检测结果即可判断何种电气设备发生故障,为巡检人员提供维修依据。     

基于高精度模型的热气机振动响应计算分析研究

主要介绍了基于高精度模型的某型热气机振动响应计算分析研究。对比分析了热气机曲轴箱不同网格尺寸、不同连接方式对模态频率计算的影响,通过模态试验确定了其网格尺寸和连接方式。建立了该型热气机的有限元模型,将多体动力学计算的激励力施加至有限元模型,计算得到关键节点的振动加速度值,并基于时域和频域对比了关键节点振动响应的计算值与实测值,验证了计算结果的准确性,为进一步优化热气机的结构提供了依据。     

Modeling of universal motor performance and brush commutation usingfinite element computed inductance and resistance matrices

This paper presents a computer aided model for the simulation of universal motor performance and brush commutation. The model consists of a set of flux linkage based differential equations. Time stepping integration method and 2D finite element field solutions are used for solving the system. An arcing model is introduced into the system to predict brush arcing and the arcing related energy. Computed results and test data are compared in the paper for a one armature coil per slot motor     

Microstructure changes in the catalyst layers of PEM fuel cells induced by load cycling: Part I. Mechanical model

To achieve a better understanding of the degradation phenomena of polymer electrolyte membrane fuel cells (PEMFCs), it is imperative to understand the mechanism of microstructure changes in the catalyst layer. To this end, a rate-dependent isotropic plasticity model with temperature- and humidity-dependent material properties is proposed to describe the viscoplasticity of the catalyst layer components. To understand the mechanism of such changes caused by the cycling of start-up and shutdown during the operation of a PEMFC, the material model, combined with the cohesive zone model and the contact model, is solved using the finite element method. The cohesive zone model and the frictional contact model are used to describe the evolution of interfaces between the protonic and the electronic conducting phases. Numerical simulation, based on the representation of the microstructure in the catalyst layers, shows that there is competition between crack initiations in the bulk material of the protonic phase and delamination between different phases. This competition plays an important role in microstructure changes in the catalyst layers. The reduction of connectivity between the protonic and the electronic conducting phases, which may explain the decrease of performance after certain duty cycles, could be contributed to by cracking or delamination.     

Study on heat transfer of leakage flow in tooth tip clearance for single screw compressor based on fuzzy contourlet finite element method

Heat transfer of leakage flow in tip clearance will reduce the working performance, and therefore it is necessary to study it in depth. To improve the computing effectiveness of heat transfer of leakage flow in the tooth tip clearance of the single-screw compressor, the fuzzy contourlet finite element model is constructed by combining the contourlet finite element method and fuzzy finite element method. First, the related research progresses are summarized. Second, heat transfer model of leakage flow in the tip clearance of single-screw compressor is constructed. Third, the fuzzy contourlet wavelet finite element model is established. Finally, heat transfer simulation of leakage flow in the tip clearance of single-screw compressor is performed, and the variables with fuzziness are chosen, which are transformed to random variables based on information entropy theory. The comparing analysis among simulation analysis and test results is performed, and results show that the contourlet finite element method has highest computing precision and efficiency. In addition, the temperature of leakage flow in the tip clearance (L1) is also obtained, and results show that the fuzzy contourlet wavelet finite element method can effectively obtain the temperature distribution rules with fuzziness.     

A static exciter with interleaved buck converter for synchronous generators

In this study, an interleaved buck converter based static excitation system is proposed for large-scale synchronous generators where thyristor controlled systems are widely used. The proposed system removes the slow response drawback of the thyristor controlled systems even for dynamic load conditions. The finite element analysis based model of the synchronous generator's electromagnetic system is obtained and co-simulations of the modeled generator and proposed interleaved buck converter are performed. Results obtained from simulation results show that, the proposed system offers better performance in terms of step response and inductor current ripple. The simulation results are validated with experimental studies. All measurement, monitoring and control processes have been performed with field programmable gate array called NI CompactRIO platform and LabVIEW software.     

基于DDAM方法的排气降温装置抗冲结构优化设计

基于动态设计方法(DDAM),以某排气降温装置为对象建立有限元仿真计算模型,开展了动态冲击响应计算分析,并在此基础上提出了结构优化方案.基于结构优化前后的冲击应力响应结果对比,明确了提高排气降温装置抗冲击性能的结构优化方向.     

BeamDyn: a high‐fidelity wind turbine blade solver in the FAST modular framework

This paper presents a numerical implementation of the geometrically exact beam theory based on the Legendre‐spectral‐finite‐element (LSFE) method. The displacement‐based geometrically exact beam theory is presented, and the special treatment of three‐dimensional rotation parameters is reviewed. An LSFE is a high‐order finite element with nodes located at the Gauss–Legendre–Lobatto points. These elements can be an order of magnitude more computationally efficient than low‐order finite elements for a given accuracy level. The new module, BeamDyn, is implemented in the FAST modularization framework for dynamic simulation of highly flexible composite‐material wind turbine blades within the FAST aeroelastic engineering model. The framework allows for fully interactive simulations of turbine blades in operating conditions. Numerical examples are provided to validate BeamDyn and examine the LSFE performance as well as the coupling algorithm in the FAST modularization framework. BeamDyn can also be used as a stand‐alone high‐fidelity beam tool. Copyright © 2017 John Wiley & Sons, Ltd.     

仿生热鲁棒结构的传感器优化配置

对热压电仿生结构的传感器配置优化进行了研究。利用准静态热压电本构关系，得到了热压电仿生结构的有限元动态耦合模型，讨论了各耦合因素对热压电传感特性的影响。在此基础上，提出了一种热压电结构的有限元分析方法，并对受温度场作用的热压电结构进行了数值仿真研究；根据仿真计算结果分析，最终确定传感器的最佳布置。     

Temperature field analysis of tangential clearance leakage flow for scroll compressor based on fuzzy ridgelet finite element method

To improve the computing precision and efficiency of temperature field analysis in tangential clearance of scroll compressor, the ridgelet finite element method is combined with fuzzy finite element method to construct the fuzzy ridgelet finite element method of analyzing temperature field in tangential clearance. First, the related research progresses on heat transfer of scroll compressor, wavelet finite element method, and fuzzy finite element method are summarized. Second, the leakage flow model of tangential clearance in scroll compressor is studied in depth. Third, the heat transfer model of leakage flow in tangential clearance of scroll compressor is established, and then the fuzzy ridgelet finite element model is constructed, the fuzzy finite element model is transformed to the random model based on information entropy, the corresponding calculating procedure is designed. Finally, the simulation analysis is performed based on fuzzy finite element method, fuzzy Daubechies wavelet finite element method, and the fuzzy ridgelet finite element model, respectively, comparing analysis between simulation and test results shows that the fuzzy ridgelet finite element method has best computing effectiveness on temperature field analysis of tangential clearance of scroll compressor. In addition, the tangential clearance temperature of scroll compressor with and without water cooling has been analyzed based on the fuzzy ridgelet finite element method, and the results show that the water cooling system can reduce the temperature in tangential clearance greatly.     

In-wheel permanent-magnet brushless DC motor drive for an electricbicycle

This paper presents the design of an axial-field PM brushless DC motor drive for use on an electric bicycle. Details of the motor and the electronic converter are given. Performance analysis using the finite element method is briefly discussed. A prototype motor was constructed for verifying the actual performance. Good correlation between the theoretical and experimental results hs been obtained. Test results confirmed the feasibility of the proposed motor design     

异型聚合物锂离子电池扭转条件下的电性能有限元分析

基于有限元的思想,将异型聚合物锂离子电池结构能源构件等效为许多块微平板电池的组合,通过研究平板电池纯扭转条件下单位长度扭转角与电性能的关系,结合构件的有限元力学模型,引用材料力学、弹性力学等相关理论,建立了复杂曲面构件扭转承载条件下的电性能有限元分析模型,初步实现了构件扭转条件下,力学性能与电性能的同步校核,为有限元思想应用于复杂结构能源构件的设计及承载条件下的电性能研究做了有益探讨。