检索结果-南通市图书馆

A Modified Iterative Learning Control Approach for the Active Suppression of Rotor Vibration Induced by Coupled unbalance and Misalignment

引用

Chinese Journal of Mechanical Engineering 2024年第1期37卷 242-253页

作者： Yifan Bao Jianfei Yao Fabrizio Scarpa Yan Li College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of High-end Compressor and System Technology Beijing 100029China Beijing Key Laboratory of High-end Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029China Key Lab of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029China Bristol Composites Institute(ACCIS) University of BristolBristol BS81TRUK Dynamics and Control Research Group(DCRG) University of BristolBristol BS81TRUK

This paper proposes a modified iterative learning control(MILC)periodical feedback-feedforward algorithm to reduce the vibration of a rotor caused by coupled unbalance and parallel misalignment.The control of the vibration of the rotor is provided by an active magnetic actuator(AMA).The iterative gain of the MILC algorithm here presented has a self-adjustment based on the magnitude of the vibration.Notch filters are adopted to extract the synchronous(1×Ω)and twice rotational frequency(2×Ω)components of the rotor vibration.Both the notch frequency of the filter and the size of feedforward storage used during the experiment have a real-time adaptation to the rotational speed.The method proposed in this work can provide effective suppression of the vibration of the rotor in case of sudden changes or fluctuations of the rotor speed.Simulations and experiments using the MILC algorithm proposed here are carried out and give evidence to the feasibility and robustness of the technique proposed.

关键词： Rotor vibration suppression Modified iterative learning control unbalance Parallel misalignment Active magnetic actuator

来源：

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

Model-Based Degree Estimation of unbalance and Misalignment in Flexible Coupling-rotor System

引用

Chinese Journal of Mechanical Engineering 2009年第4期22卷 550-556页

作者： LI Changyou XU Minqiang GUO Song WANG Yuewu WANG Rixin School of Astronautics Harbin Institute of Technology Harbin 150001 China School of Computer Science and Technology Harbin Engineering University Harbin 150001 China School ofMechanicalEngineering andAutomation Northeastern University Shenyang 110004 China

The condition of rotor system must be assessed in order to develop condition-based maintenance for rotating machinery. It is determined by multiple variables such as unbalance degree, misalignment degree, the amount of bending deformation of the shaft, occurrence of shaft crack of rotor system and so on. The estimation of the degrees of unbalance and misalignment in flexible coupling-rotor system is discussed. The model-based approach is employed to solve this problem. The models of the equivalent external loads for unbalance and misalignment are derived and analyzed. Then, the degrees of unbalance and misalignment are estimated by analyzing the components of the equivalent external loads of which the frequencies are equal to the 1 and 2 times running frequency respectively. The equivalent external loads are calculated according to the dynamic equation of the original rotor system and the differences between the dynamical responses in normal case and the vibrations when the degree of unbalance or misalignment or both changes. The denoise method based on bandpass filter is used to decrease the effect of noise on the estimation accuracy. The numerical examples are given to show that the proposed approach can estimate the degrees of unbalance and misalignment of the flexible coupling-rotor system accurately.

关键词： model-based approach degree estimation misalignment unbalance rotor system flexible coupling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

DISTRIBUTION LAW OF RANDOM unbalance RESPONSE OF MULTISTAGE BLOWER

引用

中国有色金属学会会刊：英文版 1998年第1期8卷 165-168页

作者： Tan, Qing Zhong, Jue Central South Univ of Technology Changsha China

ＤＩＳＴＲＩＢＵＴＩＯＮＬＡＷＯＦＲＡＮＤＯＭＵＮＢＡＬＡＮＣＥＲＥＳＰＯＮＳＥＯＦＭＵＬＴＩＳＴＡＧＥＢＬＯＷＥＲ①ＴａｎＱｉｎｇａｎｄＺｈｏｎｇＪｕｅＣｏｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌａｎｄＥｌｅｃｔｒｉｃａｌ... 详细信息

ＤＩＳＴＲＩＢＵＴＩＯＮＬＡＷＯＦＲＡＮＤＯＭＵＮＢＡＬＡＮＣＥＲＥＳＰＯＮＳＥＯＦＭＵＬＴＩＳＴＡＧＥＢＬＯＷＥＲ①ＴａｎＱｉｎｇａｎｄＺｈｏｎｇＪｕｅＣｏｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌａｎｄＥｌｅｃｔｒｉｃａｌＥｎｇｉｎｅｒｉｎｇ，Ｃｅｎｔｒａ...

关键词： unbalance distribution random experiment method vibration response centrifugal blower overcritical rotating speed autobalance technology working condition diagnosis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of overhead line current unbalance in meshed grids and its reduction

引用

Journal of Modern Power Systems and Clean Energy 2018年第6期6卷 1204-1212页

作者： Jakub EHRENBERGER Jan ?VEC Department of Electrical Power Engineering Czech Technical University in Prague

This paper describes new methodology in the current unbalance calculations in meshed grids. The meshed grids, mainly the transmission ones, consist of more parts connected together which are formed using different conductor types, phase sequence arrangements,tower constructions, and various number of lines on the same tower. Therefore several computational challenges arise in comparison with the widely discussed point-topoint configuration. The methodology divides the grid into a number of impedance matrices respecting all the self and mutual impedances among all conductors and all parallel lines. Another challenging issue for the line impedancedescription is changing the number of shield wires along the line if the line is composed of several sections with different tower configurations. For the current unbalance calculation, shield wires must also be included in the algorithms, and matrices of various dimensions can be obtained. For the overall matrix description to be used,dimensions of all matrices in final equations must be equal,and therefore the virtual shield wires are created. To compare more conductor transposition cases with each other, the line loadings caused by voltage sources should be equal. This is necessary mainly in case of meshed grids where the supplying sources on different lines can have strong mutual couplings. This can be achieved by an appropriately designed optimization of the connected voltage sources.

关键词： Current unbalance Phase sequence arrangement Shield wire unbalance factor Zero-sequence set

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improved direct power control of a grid-connected voltage source converter during network unbalance

引用

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第10期11卷 817-823页

作者： Peng ZHOU Wei ZHANG Yi-kang HE Rong ZENG School of Electrical Engineering Zhejiang University Hangzhou 310027 China

This paper deals with an improved direct power control(DPC) strategy for the pulse width modulation(PWM) voltage source converter(VSC) under unbalanced grid voltage conditions.In order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid faults.In this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential decomposition.As a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.

关键词： Voltage source converter Direct power control unbalance Resonant controller

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic analysis and identification of unbalance and misalignment in a rigid rotor with two offset discs levitated by active magnetic bearings:a novel trial misalignment approach

引用

Propulsion and Power Research 2021年第1期10卷 58-82页

作者： Prabhat Kumar Rajiv Tiwari Department of Mechanical Engineering Indian Institute of Technology GuwahatiGuwahatiAssam781039India

Rotating machinery is an essential and crucial component of numerous mechanical systems in modern industries,transport vehicles,and in several other applications.Excessive vibrations on rotating equipment due to multiple faults may cause catastrophic failure in machines and lead to hazardous accidents.So,there is a need for perceiving the dynamic nature and identifying the faults for the safe,smooth and effective operation of machines.This paper proposes a novel trial misalignment approach to estimate the misalignment with a similar concept as the trial unbalance in the rotor balancing.Active magnetic bearing(AMB)misalignment with the rotor has been investigated with residual misalignment and additional trial misalignment cases.Additional trial misalignments are provided in addition to the unknown misalignments of the residual misalignment case.For the execution of this methodology,the dynamic model of a four-degree-of-freedom unbalanced and misaligned rigid rotor with two offset discs supported by two active magnetic bearings has been mathematically developed.The offset discs result in the gyroscopic effect at high rotor speeds.Equations of motion of the rotor-AMB system have been derived and solved to generate the time domain rotor displacement and controlling current responses at AMB positions.A fast Fourier transform technique has been utilized to convert the time domain responses into the frequency domain for estimation of unbalance eccentricities and phases together with force-displacement and forcecurrent stiffnesses of misaligned AMBs as well as AMB's constant forces using the developed identification algorithm.Identified values of AMB's parameters for both residual and additional trial misalignment cases are evaluated to estimate the four unknown misalignments.Testing of the algorithm has also been carried out at multiple spin speeds against measurement signal noise in rotor responses and bias errors in rotor system parameters to check its effectiveness and robustness.The algorithm is found to be exhi

关键词： Misalignment unbalance Active magnetic bearing Gyroscopic moment Fast Fourier transform Identification

来源：

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

A Practical Strategy of unbalance Identification and Correction for 2-DOF Precision Centrifuges

引用

Journal of Harbin Institute of Technology(New Series) 2018年第1期25卷 29-38页

作者： Xin Huo Shuangpeng Zheng Yu Yao Weishan Chen Control and Simulation Center School of AstronauticsHarbin Institute of Technology School of Mechatronics Engineering Harbin Institute of Technology

unbalance existing in the mechanical systems is one of the most common causes which leads to unexpected vibration,nonsmooth motions,uncertain dynamics and even instability. In this paper,the problem of unbalance identification and correction is investigated for the countershaft system of a precision centrifuge with two degrees of freedom. According to the characteristics of the load under test installed on the countershaft,a gradual subdivision algorithm is proposed to identify the phase of the unbalance,and its amplitude is calculated by using a space vector algorithm,where the vibration information of the mainshaft system is obtained by utilizing two axis-layout displacement transducers installed associated to the mainshaft.Based on ADAMS software,some numerical simulations are presented and compared,and further,the validity of the strategy is demonstrated by experimental examples.

关键词： dynamic unbalance identification and correction precision centrifuge countershaft system ADAIMS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

unbalance Level Regulating Algorithm in Power Distribution Networks

引用

Energy and Power Engineering 2018年第2期10卷 65-76页

作者： Eugene Alekseevich Shutov Tatyana Evgenievna Turukina Ilya Igorevich Elfimov Tomsk Polytechnic University Tomsk Russia

The paper dwells on the unified power quality indexes characterizing the phenomenon of voltage unbalance in three-phase systems. Voltage unbalance is one of the commonest occurrences in the town mains of 0.38 kV voltage. The phenomenon describes as inequality of vector magnitude of phase voltage and shearing angle between them. Causes and consequences of the voltage unbalance in distribution networks have been considered. The algorithm, which allows switching one-phase load, has been developed as one of the methods of reducing the unbalance level. The algorithm is written in the function block diagram programming language. For determining the duration and magnitude of the unbalance level it is proposed to introduce the forecasting algorithm. The necessary data for forecasting are accumulated in the course of the algorithm based on the Function Block Diagram. The algorithm example is given for transforming substation of the urban electrical power supply system. The results of the economic efficiency assessment of the algorithm implementation are shown in conclusion. The use of automatic switching of the one-phase load for explored substation allows reducing energy losses (active electric energy by 7.63%;reactive energy by 8.37%). It also allows improving supply quality to a consumer. For explored substation the average zero-sequence unbalance factor has dropped from 3.59% to 2.13%, and the negative-sequence unbalance factor has dropped from 0.61% to 0.36%.

关键词： unbalance Supplementary Power Losses Load Switching Algorithm Electric Power Quality Distributing Networks Function Block Balancing System Forecasting Microcontroller

来源：

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

Mitigation of unbalanced Voltage Sags and Voltage unbalance in CIGRE Low Voltage Distribution Network

引用

Energy and Power Engineering 2013年第9期5卷 551-559页

作者： Ghullam Mustafa Bhutto Birgitte Bak-Jensen Pukar Mahat Carlo Cecati Department of Energy Technology Aalborg University Aalborg Denmark Department of Energy Technology Aalborg University Aalborg Denmark Department of Electrical Power Quaid-E-Awam University of Sciences & Technology Nawabshah Pakistan Department of Information Engineering Computer Sciences and Mathematics Via G. Gronchi L’Aquila Italy

Any problem with voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM) etc. can be used to mitigate the voltage problems in the distribution system. The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and networks like this. The voltage unbalances, for the tested cases in the CIGRE LV test network are mainly due to single phase loads and due to unbalanced faults. The compensation of unbalanced voltage sags and voltage unbalance in the CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0.

关键词： Power Quality unbalanced Voltage Sags Mitigation of Voltage unbalance Voltage unbalance Factor (VUF) Distributed Static Compensator (STATCOM)

来源：

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

Performance Analysis of unbalance Radial Feeder with Time Varying Composite Load

引用

Journal of Power and Energy Engineering 2015年第5期3卷 56-70页

作者： Jagdish Prasad Sharma H. Ravishankar Kamath Mewar University Chittorgarh India Malwa Institute of Technology Indore India

The focus of this paper is to present performance indices for unbalance radial feeder having different characteristic and composition of time varying static ZIP load models. These provide a framework for benchmarking of distribution automation projects. 15 minutes characteristics time interval for load flow and load modeling are considered to meet smart grid implementation criterion. A forward-backward sweep method is employed for load flow solution. Developed performance indices were illustrated on modified IEEE 37 node test feeder. Performance indices are useful for analysis, operational, planning and integration of stochastic renewable sources.

关键词： Voltage sensitive load Performance Indices unbalance load flow Radial distribution feeder Stochastic load modeling Modeling

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：