基于Bond Graph的风力发电机建模

简单介绍了Bond Graph的状态变量、标准元件和建模方法等基本概念。基于Bond Graph能深入描述系统内部变化过程,对复杂系统物理模型研究更具优势,将其引入电力系统,在笼型三相异步风力发电机数学模型的基础上,提出基于Bond Graph理论的风力发电机建模与仿真,重点研究分析了发电机abc-αβ0坐标变换的Bond Graph模型,以及描述发电机定子和转子之间电磁联系的惯性场、电量与机械量转换关系以及描述发电机机械转矩的Bond Graph模型,在此基础上得出完整的风力发电机模型,并利用20-Sim软件进行了仿真,仿真结果验证了该模型的正确性。

Global Dynamic Modeling of Electro-Hydraulic 3-UPS/S Parallel Stabilized Platform by Bond Graph

Dynamic modeling of a parallel manipulator（PM） is an important issue. A complete PM system is actually composed of multiple physical domains. As PMs are widely used in various fields, the importance of modeling the global dynamic model of the PM system becomes increasingly prominent. Currently there lacks further research in global dynamic modeling. A unified modeling approach for the multi-energy domains PM system is proposed based on bond graph and a global dynamic model of the 3-UPS/S parallel stabilized platform involving mechanical and electrical-hydraulic elements is built. Firstly, the screw bond graph theory is improved based on the screw theory, the modular joint model is modeled and the normalized dynamic model of the mechanism is established. Secondly, combined with the electro-hydraulic servo system model built by traditional bond graph, the global dynamic model of the system is obtained, and then the motion, force and power of any element can be obtained directly. Lastly, the experiments and simulations of the driving forces, pressure and flow are performed, and the results show that, the theoretical calculation results of the driving forces are in accord with the experimental ones, and the pressure and flow of the first limb and the third limb are symmetry with each other. The results are reasonable and verify the correctness and effectiveness of the model and the method. The proposed dynamic modeling method provides a reference for modeling of other multi-energy domains system which contains complex PM.

The bond graph model of planar flexible multibody mechanical systems and its dynamic principle

In order to increase the efficiency and reliability of the dynamic analysis for flexible planar linkage containing the coupling of multi-energy domains, a method based on bond graph is introduced. From the viewpoint of power conservation, the peculiar property of bond graph multiport element MTF is discussed. The procedure of modeling planar flexible muhibody mechanical systems by bond graphs and its dynamic principle are deseribed. To overcome the algebraic difficulty brought by differential causality anti nonlinear junction structure, the constraint forces at joints can be considered as unknown effort sources and added to the corresponding O-junctions of system bond graph model. As a result, the automatic modeling on a computer is realized. The validity of the procedure is illustrated by a practical example.

基于Bond Graph的电机驱动转子系统振动特性研究

电机驱动的转子系统是工业领域中很常见的机电耦合系统,其动力学行为及振动特性是影响机电系统安全运行的重要因素。Bond Graph作为一种基于功率流的建模方法,对复杂的耦合系统动力学建模具有独特的优势。基于Bond Graph建立了电机驱动转子系统的动力学分析模型,以该模型为基础仿真分析了机电耦合系统的动力学特性。结合转子试验台,研究了电机工况变化及不对中故障情况下,转子系统的振动特性变化规律。仿真结果与试验台实验结果相吻合,验证了该Bond Graph模型的准确性和有效性。

Modeling and Simulation of Hydraulic Long Transmission Line by Bond Graph

This paper addresses the issue of modeling of the hydraulic long transmission line. In its base, such model is nonlinear with distributed parameters. Since general solution in closed-form for such model in time-domain is not available, certain simplifications have to be introduced. The pipeline in the paper has been divided to a cascaded network of n segments so that a model with lumped parameters could be reached. For segment modeling, a standard library of bond graphs element has been used. On the basis of models with lumped parameters, the effect of the number of segments, pipeline length and effective bulk modulus on the dynamics of long transmission line have been analyzed.

VECTOR BOND GRAPH REPRESENTATION OF FINITE ELEMENT METHOD IN STRUCTURAL DYNAMICS

In this paper we have shown that the invariance of energy(kinetic energy,potential energy)and virtual work is the common feature of vector bond graph and finite element method in struc-tural dynamics.Then we have discussed the vector bond graph representation of finite elementmethod in detail,there are:(1)the transformation of reference systems,(2)the transformation ofinertia matrices,stiffness matrices and vectors of joint force,(3)verctor bond graph representationof Lagrangian dynamic equation of structure.

ANALOGY BETWEEN TRANSFER MATRIX AND BOND GRAPH IN VIBRATION PROBLEMS

In this paper we have disucced the analogy between transfer matrix and bond graph, chiefly asfollows: ① Power or energy flow is their common characteristic, ② Lumped masses and elasticmembers in transfer matrix just correspond respectively to the inertia and the capacitance elementsin the bond graph, ③ Point transfer matrix and field transfer matrix behave respectively as 1-and0-junction in bond graph,

基于bond-graphs的机电系统建模和仿真

研究了多领域机电系统的键合图建模方法,在此基础上采用20-sim软件包对直流电机伺服系统进行建模和仿真,设计了LQG控制器。建模和仿真过程表明,键合图法建模简练、实用,是一种理想的多领域机电系统图形建模方法,其参数与物理组件直接相关,可广泛应用于多领域机电系统的建模和仿真。

Dynamic Simulations of Nonlinear Multi-Domain Systems Based on Genetic Programming and Bond Graphs

A dynamic simulation method for non-linear systems based on genetic programming （GP） and bond graphs （BG） was developed to improve the design of nonlinear multi-domain energy conversion systems. The genetic operators enable the embryo bond graph to evolve towards the target graph according to the fitness function. Better simulation requires analysis of the optimization of the eigenvalue and the filter circuit evolution. The open topological design and optimized convergence for the operation, but also the design of nonlinear multi-domain systems. space search ability of this method not only gives a more reduces the generation time for the new circuit graph for

The atom-bond connectivity index of chemical bicyclic graphs

The atom-bond connectivity（ABC） index provides a good model for the stability of linear and branched alkanes as well as the strain energy of cycloalkanes,which is defined as ABC（G） =∑ uv∈E（G） √d u＋dv-2 dudv,where du denotes the degree of a vertex u in G.A chemical graph is a graph in which no vertex has degree greater than 4.In this paper,we obtain the sharp upper and lower bounds on ABC index of chemical bicyclic graphs.

基于BondGraph模型的定性故障诊断方法

研究一种基于键合图(Bond Graph)模型的定性故障诊断方法。根据Bond Graph模型元件中有关参数和变量的特定因果关系,推导出当某观测参量发生变化时,系统内所有可能产生故障的部位,并在此基础上预测每个故障的将来状态,通过与系统实际观测特征比较,在可能产生故障的集合中准确定位故障源。通过实例仿真验证,该方法是便捷有效的。

基于键合图理论的斜盘多柱塞泵建模与仿真

为了研究9个柱塞组合而成的斜盘式轴向柱塞泵的性能特征,应用键合图理论,通过AMESim仿真平台建立模型,研究斜盘倾角和配流盘窗口前端的减振槽对柱塞泵流量脉动的影响,分析扩展模型中斜盘所受的力矩。结果表明:柱塞泵斜盘倾角越大,输出的流量越多,流量脉动幅度越大;配流盘窗口的减振槽形状和大小越合理,流量脉动越小;用AMESim仿真平台中的接收和发射元件可以扩展模型,获得斜盘所受的力矩曲线。

省际地方政府债券信用风险及其溢出效应——基于图注意力网络模型的分析

本文基于复杂网络视角考察省际地方政府债券信用风险及其溢出效应。根据2016—2022年我国地方政府债务在二级市场的月度信用利差及其特征变量,识别了信用利差的变化情况,揭示了信用利差与债券相关指标之间的内在关联。采用图注意力网络模型对地方政府债券信用风险及其影响因素进行评估,考察各类因素在影响信用风险时的交互效应,以及这些因素如何通过复杂网络对地方政府债券信用风险产生直接和间接的影响。在此基础上,本文通过分析省际地方政府债券风险的溢出效应,识别出地方政府债务风险的省际传导机制和部分省份之间债务风险相互增强的特点。基于上述结论,本文从完善二级市场风险预警体系、增强风险溢入效应较强省份财政稳定性、提高风险溢出效应较强省份债务管理水平、建立风险传导网络监控以及协调省际债务发行机制等方面提出政策建议。

负载口独立双阀芯电液阀的结构优化

为研究负载口独立电液阀系统结构参数对主阀微动特性的影响,基于功率键合图理论,建立了电液阀系统状态空间方程,采用一阶灵敏度方法,分析了系统参数对主阀微动特性的影响规律;反馈控制系统的先导结构参数对主阀运动特性至关重要,以系统不产生自激振荡与最佳阻尼比为约束条件,对先导级死区宽度、阀口形式、进回油阀口匹配系数进行研究,实现了先导级主级最佳匹配。研究结果表明,对主阀微动特性影响较大的因素依次为主阀芯所受摩擦力、非弹簧控制腔液容、导阀入口到主阀控制腔管路液容(非弹簧侧)、主阀弹簧预紧力,对上述影响参数进行优化的同时,当导阀死区宽度δ≤0.25 mm,阀口形式为U形阀口,进回油阀口匹配系数η=0.53时,系统综合性能可得到有效提高。

基于键合图的环切机构动力学建模及其非线性振动研究

管道切口端面的质量是保障管路系统安全运行的重要因素之一,但在管道切削过程中存在非线性因素,可能会导致切管机发生混沌、拟周期等有害振动,从而影响切削精度和加工质量。因此,揭示切管机动力学失稳的机制以避免有害振动是改善运转性能、提高切削精度的关键。以一种刀旋式切管机的环切机构为对象,基于键合图理论建立了机构的动力学模型,通过计算灵敏度确定了关键动力学参数,并综合应用分岔图、Lyapunov指数图、相图、时间响应图等,揭示了关键参数的分岔机制。结果表明,随着激励幅值、激励频率和基座弹性系数等参数的变化,系统会存在倍周期分岔、Hopf分岔、混沌和吸引子共存等复杂动力学行为,从而产生严重降低切削质量的振动和运动突变。研究结果可为该机构后续动态性能优化和有害振动抑制提供参考。

基于符号键合图的电静压伺服机构多故障诊断研究

针对电静压伺服机构(EHA)服役时存在多种故障且难以诊断的问题,提出了一种考虑参数贡献度的符号键合图(SBG)故障诊断方法。首先,根据EHA工作原理与键合图理论构建了键合图模型,设定了系统参数数值及分布标准差,再利用键合图模型推导了其解析冗余式(ARR),并构建了故障特征矩阵,将键合图模型转换为符号键合图模型,根据符号键合图元件之间的因果关系和一致性路径,推理出了EHA可能故障集;然后,定义并计算了EHA系统参数贡献度,筛选出了高贡献度系统参数,对可能故障集中难以引起解析冗余式残差数据变化的低贡献度系统参数进行了剔除,缩小了可能的故障参数范围;最后,利用键合图仿真软件20-sim,通过改变EHA中Q轴电阻与电机磁通链的数值,进行了多故障仿真实验,对所提多故障诊断方法进行了验证。研究结果表明:当EHA发生多故障时,将剔除低贡献度系统参数的可能故障集同传感器数据、解析冗余式残差数据进行结合,能准确诊断出预置的两个高贡献度故障参数,相比于常规SBG故障诊断的可能故障集,能更准确地锁定EHA系统故障参数。

基于机理模型与深度学习的密炼工艺预测控制方法

针对轮胎生产中密炼工艺的时变特性以及生产多要素对过程控制的要求,采用键合图和深度学习算法设计了一种模型预测控制方法,形成了对密炼过程生产多要素的有效控制。通过状态空间方程模型加反馈校正的方式,减小线性预测模型与非线性过程间误差;通过卷积神经网络(CNN)提取密炼工艺过程数据特征,通过长短期神经网络(LSTM)提取数据前后的时序关系;提出基于CNN-LSTM网络结构的系统参数辨识方法,实时更新状态空间预测模型参数,实现了预测模型与密炼过程的精准匹配。仿真结果验证了所提方法的有效性。

基于功率键合图理论的仿生馈能减震座椅设计

为有效衰减工程机械车辆的低频振动,设计了一种应用于重型车辆的馈能减震座椅.首先,模仿袋鼠下肢骨骼的多连杆串联结构设计“X”型减震结构;其次,利用功率键合图建立减震座椅模型,通过MATLAB/Simulink模块进行数值仿真;最后,采用SolidWorks建立三维模型,导入ADAMS进行运动仿真,并与数值仿真结果进行对比分析.仿真结果表明:振动频率越大,能量回收系统的输出功率越高;当振动频率为2 Hz时,峰值输出功率为0.75 W,能够为车辆内各传感器供电,进而实现减震和馈能.该设计为减震座椅的馈能特性研究提供了新思路.

舰载直升机电驱动助降装置及其关键特性分析

针对现役综合系留和转运系统(Aircraft Ship Integrated Secure and Traverse,ASIST)存在的捕获冲击力大、转运时系统能耗高的问题,设计舰载直升机电驱动助降装置。通过分析助降装置的工况得出助降装置在执行捕获与转运任务时的性能要求,据此给出电驱动助降装置传动系统的设计方案。基于功率键合图理论建立传动系统的动力学模型,并与液压驱动助降装置进行对比仿真实验。仿真结果表明:电驱动助降装置的捕获速度降低约92%,捕获时最大冲击力降低约94%,能够在21 kN的外负载作用下执行直升机转运任务,在执行转运任务时能耗降低约29%,该成果对于拓宽ASIST的使用范围、降低系统能耗具有重要意义;所引入的兼顾系统动态特性与能耗特性的建模方法,为其余复杂机械系统的动力学建模提供了参考。

基于键合图的船舶管路系统建模研究

面向船舶智能化背景下船舶管路系统建模的精细化要求,提出了一种基于键合图的船舶管路系统建模方法。根据船舶管路系统的类型划分以及运行特点,分析了影响管路系统建模准确性的因素,并按照不同的运行状况及建模需求对管路系统的键合图模型层次进行了划分,确定以船舶海水管路系统为实例,建立了海水管路系统的试验台。在仿真环境中验证了海水管路试验台键合图模型的准确性和有效性,为船舶管路系统的建模仿真提供了一种新思路。