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Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

Le YANG, Shuo WANG, Jianghua FENG

《机械工程前沿（英文）》 2018年 第13卷 第3期   页码 329-353 doi: 10.1007/s11465-018-0466-1

摘要：

Electromagnetic interference (EMI) causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive (VFD) systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifier-inverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifier-inverter systems are also summarized. EMI noise suppression techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.

关键词： variable-frequency drive (VFD)     electromagnetic interference (EMI)     motor drive modeling     EMI noise suppression    

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新型双馈变速凸极同步电机

宁玉泉

《中国工程科学》 2004年 第6卷 第12期   页码 27-31

摘要：

提出一种新型双馈变速凸极同步电机，阐述了它的基本原理和结构，电机的转子采用分裂磁极和正交绕组, 结构简单、可靠。转子绕组由低频交流变频电源供电，使电机具有变速恒频的特性。通过原型样机的试验，验证了该项发明的正确性和实用性，它将在大型水电、风电中得到广泛应用。

关键词： 凸极同步电机 变速恒频 交流励磁 双馈    

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Dynamic contribution of variable-speed wind energy conversion system in system frequency regulation

Yajvender Pal VERMA, Ashwani KUMAR

《能源前沿（英文）》 2012年 第6卷 第2期   页码 184-192 doi: 10.1007/s11708-012-0185-y

摘要： Frequency regulation in a generation mix having large wind power penetration is a critical issue, as wind units isolate from the grid during disturbances with advanced power electronics controllers and reduce equivalent system inertia. Thus, it is important that wind turbines also contribute to system frequency control. This paper examines the dynamic contribution of doubly fed induction generator (DFIG)-based wind turbine in system frequency regulation. The modified inertial support scheme is proposed which helps the DFIG to provide the short term transient active power support to the grid during transients and arrests the fall in frequency. The frequency deviation is considered by the controller to provide the inertial control. An additional reference power output is used which helps the DFIG to release kinetic energy stored in rotating masses of the turbine. The optimal speed control parameters have been used for the DFIG to increases its participation in frequency control. The simulations carried out in a two-area interconnected power system demonstrate the contribution of the DFIG in load frequency control.

关键词： doubly fed induction generator (DFIG)     load frequency control     inertial control     wind energy conversion system (WECS)    

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用遗传算法求解供水泵站的效率优化问题

廖莉,林家恒,张承慧

《中国工程科学》 2002年 第4卷 第9期   页码 54-58

摘要：

供水企业向来是城市的用电大户，其用电量主要体现在泵站水泵机组的电耗上。供水泵站的高效运行对节约电能、安全供水具有极为重要的意义。文章对供水泵站的效率优化问题进行了探讨，在提出用指数曲线准确地拟合水泵性能曲线的基础上，建立了供水栗站效率优化问题的数学模型，并设计了相应的遗传算法进行求解，仿真实验结果表明了该算法合理、有效。

关键词： 供水泵站     数值拟合     优化     遗传算法    

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刮板输送机用隔爆型变频调速三相异步电动机设计

何惠明,杨晓洲,肖红,范作智,钱良,范光

《中国工程科学》 2012年 第14卷 第2期   页码 59-68

摘要：

基于煤矿井下变频调速装置与电动机一体式的隔爆型变频调速三相异步电动机实现高效、节能的研发项目，根据传统的感应电动机电磁计算程序增加变频调速电动机的计算方案，并结合ANSOFT 2D有限元针对三相异步电动机的数值分析方法，进行设计核算。详细论述了变频电机的变频调速原理、控制策略，并给出实际样机，介绍其设计与制造技术。

关键词： 防爆变频调速     三相异步电机     结构设计     电磁计算    

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风力发电变流器发展现状与展望

马伟明,肖飞

《中国工程科学》 2011年 第13卷 第1期   页码 11-20

摘要：

风电机组宽泛的使用环境，使作为机组关键设备之一的大容量变流器必须满足高功率密度、高可靠性与优良控制性能等要求。国产风电变流器的研发近几年有了较快的发展，但总体上依然落后于国外先进水平。文章对风电变流器，重点是直驱式全功率变流器的若干关键技术做了介绍，给出了相关问题的解决思路。

关键词： 风力发电     变速恒频     双馈型     直驱型     变流器    

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Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0691-5

摘要： This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments, such as unstructured or man-made operational errors through comprehensive consideration of cost, accuracy, manufacturing, and application. Based on the concept of mechanical passive compliance, which is widely implemented in robots for interactions, a finger is dedicated to improving mechanical robustness. The finger mechanism not only achieves passive compliance against physical impacts, but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory actuators. It achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust stiffness. The mechanical design of the finger and its stiffness adjusting methods are elaborated. The stiffness characteristics of the finger joint and the actuation unit are analyzed. Experimental results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the model. Fingers have been experimentally proven to be robust against physical impacts. Moreover, the experimental part verifies that fingers have good power, grasping, and manipulation performance.

关键词： multifingered hand     mechanism design     robot safety     variable stiffness actuator    

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Effect of variable heat capacities on performance of an irreversible Miller heat engine

Xingmei YE

《能源前沿（英文）》 2012年 第6卷 第3期   页码 280-284 doi: 10.1007/s11708-012-0203-0

摘要： Based on the variable heat capacities of the working fluid, the irreversibility coming from the compression and expansion processes, and the heat leak losses through the cylinder wall, an irreversible cycle model of the Miller heat engine was established, from which expressions for the efficiency and work output of the cycle were derived. The performance characteristic curves of the Miller heat engine were generated through numerical calculation, from which the optimal regions of some main parameters such as the work output, efficiency and pressure ratio were determined. Moreover, the influence of the compression and expansion efficiencies, the variable heat capacities and the heat leak losses on the performance of the cycle was discussed in detail, and consequently, some significant results were obtained.

关键词： Miller cycle     variable heat capacity     irreversibility     parametric optimization    

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Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 88-94 doi: 10.1007/s11465-013-0361-8

摘要：

Planetary gearboxes operate usually in non-stationary conditions generated mainly by variable loads applied to these transmissions. In order to understand the dynamic behavior of planetary gearboxes in such conditions, a mathematic model is developed including driving unit, transmission and load. The variability of load induces a variable speed of the transmission which is taken into account when characterizing the main dynamic parameter of the transmission which is the mesh stiffness function. This function is not periodic following the variability of the transmission speed. The computation of the dynamic response shows an intimate relation between the vibration amplitude level and the load value. As the load increase the vibration level increase. A combined amplitude and frequency modulation is observed which is well characterized using Short Time Fourier transform more suited than the spectral analysis.

关键词： planetary gearbox     non-stationary conditions     variable load     dynamic response     time frequency analysis    

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A neural network-based production process modeling and variable importance analysis approach in corn

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 358-371 doi: 10.1007/s11705-022-2190-y

摘要： Corn to sugar process has long faced the risks of high energy consumption and thin profits. However, it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of the related processes. Big data technology provides a promising solution as its ability to turn huge amounts of data into insights for operational decisions. In this paper, a neural network-based production process modeling and variable importance analysis approach is proposed for corn to sugar processes, which contains data preprocessing, dimensionality reduction, multilayer perceptron/convolutional neural network/recurrent neural network based modeling and extended weights connection method. In the established model, dextrose equivalent value is selected as the output, and 654 sites from the DCS system are selected as the inputs. LASSO analysis is first applied to reduce the data dimension to 155, then the inputs are dimensionalized to 50 by means of genetic algorithm optimization. Ultimately, variable importance analysis is carried out by the extended weight connection method, and 20 of the most important sites are selected for each neural network. The results indicate that the multilayer perceptron and recurrent neural network models have a relative error of less than 0.1%, which have a better prediction result than other models, and the 20 most important sites selected have better explicable performance. The major contributions derived from this work are of significant aid in process simulation model with high accuracy and process optimization based on the selected most important sites to maintain high quality and stable production for corn to sugar processes.

关键词： big data     corn to sugar factory     neural network     variable importance analysis    

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On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 5-15 doi: 10.1007/s11465-012-0310-y

摘要：

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

关键词： cam mechanism     variable input speed     kinematic design     dynamic design     optimal design    

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一种新颖的用于宽输入电压范围的LLC谐振变换器的变模态控制策略 Article

Hui-pin LIN,Xiao-guang JIN,Liang XIE,Jin HU,Zheng-yu LU

《信息与电子工程前沿（英文）》 2017年 第18卷 第3期   页码 410-422 doi: 10.1631/FITEE.1600029

摘要： 本文提出了一种新颖的适用于LLC谐振变换器的混合模态控制策略，可以使得LLC谐振变换器输入宽电压范围。这种控制策略结合了全桥LLC谐振变换器，半桥LLC谐振变换器，变频控制和变脉宽控制的优点。在这种控制策略下，不同的输入电压决定了不同的电路工作模态。当输入电压很低的时候，电路采用了全桥电路和变频控制（FB_VF模态）。当输入电压升高到一定值，电路切换到全桥电路和移相控制（FB_PS模态）。当输入电压进一步上升时，电路切换到半桥电路和变频控制（FB_VF模态）。这种电路模态的切换是由数字信号处理器（digital signal processor, DSP）来实现的，不需要外加辅助电路，只需要修改一下软件。从轻载到重载下，LLC谐振变换器的原边MOSFET可以实现零电压开通（zero-voltage switching, ZVS），副边二极管可以实现零电流关断（zero-current switching, ZCS）。本文用一个额定功率300 W，输出电压450 V的LLC，输入电压20 V到120 V的谐振变换器的样机验证了这个优化的控制策略。实验结果显示，在这种控制策略下，变换器的最大工作效率可以达到95.7%，并且输入电压范围扩大了3倍。

关键词： 串并联谐振变换器；全桥；半桥；变频；移相；宽范围输入电压    

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Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 711-725 doi: 10.1007/s11465-021-0647-1

摘要： The safety of human–robot interaction is an essential requirement for designing collaborative robotics. Thus, this paper aims to design a novel variable stiffness actuator (VSA) that can provide safer physical human–robot interaction for collaborative robotics. VSA follows the idea of modular design, mainly including a variable stiffness module and a drive module. The variable stiffness module transmits the motion from the drive module in a roundabout manner, making the modularization of VSA possible. As the key component of the variable stiffness module, a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously, which can eliminate the additional bending moment caused by the asymmetric structure. The design of the double-deck grooves in the lever allows the pivot to move freely in the groove, avoiding the geometric constraint between the parts. Consequently, the VSA stiffness can change from zero to infinity as the pivot moves from one end of the groove to the other. To facilitate building a manipulator in the future, an expandable electrical system with a distributed structure is also proposed. Stiffness calibration and control experiments are performed to evaluate the physical performance of the designed VSA. Experiment results show that the VSA stiffness is close to the theoretical design stiffness. Furthermore, the VSA with a proportional–derivative feedback plus feedforward controller exhibits a fast response for stiffness regulation and a good performance for position tracking.

关键词： variable stiffness actuator     variable stiffness module     drive module     symmetrical structure     double-deck grooves     expandable electrical system    

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Parametric study on the Multangular-Pyramid Concave Friction System (MPCFS) for seismic isolation

Wei XIONG, Shan-Jun ZHANG, Li-Zhong JIANG, Yao-Zhuang LI

《结构与土木工程前沿（英文）》 2020年 第14卷 第5期   页码 1152-1165 doi: 10.1007/s11709-020-0659-7

摘要： A series of comprehensive parametric studies are conducted on a steel-frame structure Finite-Element (FE) model with the Multangular-Pyramid Concave Friction System (MPCFS) installed as isolators. This new introduced MPCFS system has some distinctive features when compared with conventional isolation techniques, such as increased uplift stability, improved self-centering capacity, non-resonance when subjected to near-fault earthquakes, and so on. The FE model of the MPCFS is first established and evaluated by comparison between numerical and theoretical results. The MPCFS FE model is then incorporated in a steel-frame structural model, which is subjected to three chosen earthquakes, to verify its seismic isolation. Further, parametric study with varying controlling parameters, such as isolation foundation, inclination angle, friction coefficient, and earthquake input, is carried out to extract more detailed dynamic response of the MPCFS structure. Finally, limitations of this study are discussed, and conclusions are made. The simulations testify the significant seismic isolation of the MPCFS. This indicates the MPCFS, viewed as the beneficial complementary of the existing well-established and matured isolation techniques, may be a promising tool for seismic isolation of near-fault earthquake prone zones. This verified MPCFS FE model can be incorporated in future FE analysis. The results in this research can also guide future optimal parameter design of the MPCFS.

关键词： seismic isolation     variable frequency     near-fault earthquake     numerical study     Multangular-Pyramid Concave Friction System    

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Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 546-552 doi: 10.1007/s11708-010-0116-8

摘要： Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed.

关键词： convective heat transfer     helical coils     high Reynolds number     supercritical pressure     variable property    

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标题 作者 时间 类型 操作

Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

Le YANG, Shuo WANG, Jianghua FENG

期刊论文

新型双馈变速凸极同步电机

宁玉泉

期刊论文

Dynamic contribution of variable-speed wind energy conversion system in system frequency regulation

Yajvender Pal VERMA, Ashwani KUMAR

期刊论文

用遗传算法求解供水泵站的效率优化问题

廖莉,林家恒,张承慧

期刊论文

刮板输送机用隔爆型变频调速三相异步电动机设计

何惠明,杨晓洲,肖红,范作智,钱良,范光

期刊论文

风力发电变流器发展现状与展望

马伟明,肖飞

期刊论文

Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

期刊论文

Effect of variable heat capacities on performance of an irreversible Miller heat engine

Xingmei YE

期刊论文

Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

期刊论文

A neural network-based production process modeling and variable importance analysis approach in corn

期刊论文

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

期刊论文

一种新颖的用于宽输入电压范围的LLC谐振变换器的变模态控制策略

Hui-pin LIN,Xiao-guang JIN,Liang XIE,Jin HU,Zheng-yu LU

期刊论文

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

期刊论文

Parametric study on the Multangular-Pyramid Concave Friction System (MPCFS) for seismic isolation

Wei XIONG, Shan-Jun ZHANG, Li-Zhong JIANG, Yao-Zhuang LI

期刊论文

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

期刊论文