检索结果-南通市图书馆

Journal of Modern Power Systems and Clean Energy 2022年第3期10卷 678-688页

作者： Zhongwen Li Zhiping Cheng Jikai Si Shuhui Li School of Electrical Engineering Zhengzhou UniversityZhengzhou 450001China Department of Electrical and Computer Engineering The University of AlabamaTuscaloosaAL 35487USA

This paper proposes a novel distributed event-triggered secondary control method to overcome the drawbacks of primary control for direct current(DC)*** eventtriggered distributed communication,the proposed control method can achieve system-wide control of parallel distrubted generators(DGs)with two main control objectives:①estimate the average bus voltage and regulate it at the nominal value;②achieve accurate current sharing among the DGs in proportion to their power output ***,the proposed control strategy can be implemented in a distributed way that shares the required tasks among the ***,it shows the advantages of being flexible and ***,this paper proposes a simple event-triggered condition that does not need extra state ***,limited communication among neighbors is required only when the event-triggered condition is satisfied,which significantly reduces the communication burden at the cyber layer.

关键词： Direct current(DC)microgrid droop control event-triggered secondary control distributed consensus load sharing

Planetary Gear Profile Modification Design Based on load sharing Modelling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2015年第4期28卷 810-820页

作者： IGLESIAS Miguel FERNáNDEZ DEL RINCóN Alfonso DE-JUAN Ana Magdalena GARCIA Pablo DIEZ Alberto VIADERO Fernando Mechanical Engineering Research Group University of Cantabria

In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.

关键词： transmission planetary gear load sharing relief profile modification

Dynamic load sharing characteristics and sun gear radial orbits of double-row planetary gear train

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2015年第10期22卷 3806-3816页

作者：盛冬平朱如鹏靳广虎陆凤霞鲍和云 College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet's eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The solution of differential governing equation of motion is determined by applying the Fourier series method. The behaviors of dynamic load sharing characteristics affected by the system parameters including gear eccentricities error, ring gear's supporting stiffness, planet's bearing stiffness, torsional stiffness of first stage carrier and input rotation rate were investigated qualitatively and systematically, and sun gear radial orbits at first and second stage were explored as well. Some theoretical results are summarized as guidelines for further research and design of double-row planetary gear train at last.

关键词： double-row planetary gear load sharing time-varying stiffness torsional stiffness sun gear radial orbit

Numerical Method on load sharing Problem of Thick Laminate Joints

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2014年第1期19卷 95-101页

作者：刘龙权陈昆昆张俊琪刘无瑕汪海 School of Aeronautics and Astronautics Shanghai Jiaotong University

Accurately and efficiently predicting the load sharing of multi^bolt thick laminate joints is necessary to quicken the optimization of the large-scale structures over various design variables, and a two-dimensional （2D） finite element method （FEM） is introduced to meet such a demand. The deformation contributions of the joint zone are analyzed and calculated separately, including the shearing deformation of the fasteners shank, the bending deformation of the fasteners shank, and the bearing deformation of the fasteners and joint plates. These deformations are all transferred and incorporated into the components of the fastener＇s flexibility. In the 2D finite element model, the flexibilities of the beam elements and bush elements are used to simulate different components of the fastener＇s flexibility. The parameters of the beam elements which include the bending moment of inertia and intersection area, and the parameters of the bush elements which include the stiffness in different directions, are all obtained through equalizing the fasteners flexibilities. In addition, the secondary bending effect introduced by the single-lap joints is also taken into account to verify the flexibilities of the fasteners in practical application. The proposed FEM is testified to be more accurate than the traditional 2D FEMs and more efficient than the three-dimensional （3D） FEM in solving load sharing problem of multi-bolt single-lap thick laminate joints. With the increase of joint plates＇ thickness, the advantages of the proposed method tend to be more obvious. The proposed 2D FEM is an effective tool for designing bolted joints in large-scale composite structures.

关键词： load sharing thick laminate fastener flexibility finite element single-lap

load sharing Performance of the Main Drive System in the Shield Machine and Improvement of Control Method

在线全文

学校读者我要写书评

暂无评论

Journal of Mechanics Engineering and Automation 2012年第9期2卷 563-567页

作者： Ran Liu Weidong Li Jianzhong Sun Zhengchang Jiao School of Electrical and Electronics Engineering Dalian University of Technology Dalian 116023 Liaoning Province China Keya College Shenyang University of Chemical Technology Shenyang 110167 Liaoning Province China

Shield machine is the major technical equipment badly in need in national infrastructure construction. The service conditions of shield machine are extremely complex. The driving interface load fluctuation caused by geological environment changes and multi field coupling of stress field may lead into imbalance of redundant drive motors output torque in main driving system. Therefore, the shield machine driving synchronous control is one of the key technologies of shield machine. This paper is in view of the shield machine main driving synchronous control, achieving the system＇s adaptive load sharing. From the point of view of cutterhead load changes, nonlinear factors of mechanical transmission mechanism and the control system synchronization performance, the authors analyze the load sharing performance of shield machine main drive system in the event of load mutation. The paper proposes a data-driven synchronized control method applicable to the main drive system. The effectiveness of the method is verified through simulation and experimental methods. The new method can make the system synchronization error greatly reduced, thus it can effectively adapt to load mutation, and reduce shaft broken accident.

关键词： Shield machine cutterhead load sharing multi-motor synchronized control.

load sharing及IG评分法则在不稳定性胸腰段骨折治疗中的应用研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Load Sharing及IG评分法则在不稳定性胸腰段骨折治疗中的应用研究

Efficient Parallel Control Scheme of Single Phase Inverters

第八届全国骨科新进展、新技术学习班

作者：陈其昕浙江大学医学院附属第二医院骨科

胸腰段骨折是脊柱骨折中最常见的一种类型,由于胸腰段骨折解剖及损伤机制的复杂性,目前还没有一种完美的评分法则能涵盖一切骨折形式,达到完善指导外科治疗的目的,断钉断棒、内固定失败等并发症时有发生。本研究发现load sharing、IG评... 详细信息

胸腰段骨折是脊柱骨折中最常见的一种类型,由于胸腰段骨折解剖及损伤机制的复杂性,目前还没有一种完美的评分法则能涵盖一切骨折形式,达到完善指导外科治疗的目的,断钉断棒、内固定失败等并发症时有发生。本研究发现load sharing、IG评分法则相结合,对胸腰段骨折术前综合评估,是一种较好的评估方法,尚未见其他文献报道。

关键词：胸腰段骨折 load sharing 后路内固定不完全神经损伤椎体高度

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Efficient Parallel Control Scheme of Single Phase Inverters

Sliding-mode Control of Single-phase PWM Rectifier for DC Microgrid Applications

第二十六届中国控制会议

作者： Liu Xiaozhu 1,Zhu Rongbo 2 1.School of Automation,Wuhan University of Technology,Wuhan 430070,P.R.China2.College of Computer Science,South-Central University for Nationalities,Wuhan 430073,P.R.China

In order to parallel several single phase inverters to increase power capacity and system reliability,several control schemes are proposed:a parallel control scheme,a voltage control scheme and a load sharing control *** parallel control technique is based on preemptive priority,which makes no absolute master or slave inverter into *** order to ensure N+1 redundant structure,synchronization signal generating mechanism,a parallel digital bus and a no-conflicted protocol on the bus also are *** order to control voltage,the voltage control scheme employs a local feedback *** implement load sharing,the load sharing control scheme introduces an improved droop method to droop voltage and *** analysis of the proposed method and design procedure are *** on the simulation and experiment results,it shows that the proposed scheme can implement load sharing *** experimental results with different type loads show that the output current error is less than 1% rating current for each inverter.

关键词： Parallel control synchronization load sharing inverter

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Sliding-mode Control of Single-phase PWM Rectifier for DC Mi...