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Segmentation multi-dimensional crest factor reduction for multi-service supporting digital radio over fibre system

The Journal of China Universities of Posts and Telecommunications 2018年第2期25卷 10-22页

作者： Wang Jie Tao Xiuli Hu Xiaoguang Guan Enyi Ding Zhushun Li Wen School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China Communication Technology Research Division Beijing Institute of Aerospace Control Devices Beijing 100039 China Fifth Technology Department Beijing Aerospace Times Optical-Electronic Technology Company Limited Beijing 100039 China

A segmentation multi-dimensional crest factor reduction （SMD-CFR） algorithm is proposed for multi-service supporting digital radio over fibre （DRoF） system. Benefit from segmentation dynamic clipping threshold and clipping factor got basing on characteristics of all service bands, the SMD-CFR is able to get better peak clipping and peak to average power ratio （PAPR） reduction for multi-band combined signal. Simulation results show that SMD-CFR gets more than 2.3 reduction in PAPR for two-bands combined signal of long term evolution （LTE） , which is much better than traditional one dimensional （1D）-CFR. Meanwhile, for 64-quadrature amplitude modulation （QAM） modulation and demodulation link, it has very small effect on bit error rate （BER） and error vector magnitude （EVM） , which are controlled less than 0. 1% and 0.2% respectively. For hardware experiment, SMD-CFR obtains 4.5% increase in drain efficiency and about 4 dBc increase in adjacent channel leakage ratio （ACLR）. These are very significant for the wide band power amplifier （PA） in multi-service supporting DRoF system.

关键词： CFR multi-dimensional dynamic crest factor DRoF muhi-service supporting LTE

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de Haas-van Alphen effect and the first-principles study of the possible topological stannide Cu3Sn

arXiv

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arXiv 2022年

作者： Liu, Chengxu Li, Bin Ge, Yongheng Jiao, Wen-He Xi, Chuanying Liu, Yi Xu, Chunqiang Lu, Qi Li, Yunlong Qiu, Hang-Qiang Zhu, Qin-Qing Ren, Zhi Zhu, Ziming Qian, Dong Ke, Xianglin Xu, Xiaofeng Key Laboratory of Quantum Precision Measurement of Zhejiang Province Department of Applied Physics Zhejiang University of Technology Hangzhou310023 China New Energy Technology Engineering Laboratory of Jiangsu Province School of Science Nanjing University of Posts and Telecommunications Nanjing210023 China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal University Changsha 410081 China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory Chinese Academy of Sciences Hefei230031 China School of Physics Key Laboratory of MEMS The Ministry of Education Southeast University Nanjing211189 China Department of Physics and Astronomy Michigan State University East LansingMI48824-2320 United States Shenyang National Laboratory for Materials Science School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Department of Applied Physics Zhejiang University of Science and Technology Hangzhou310023 China Key Laboratory for Quantum Materials of Zhejiang Province School of Science Westlake University Hangzhou310024 China Institute of Natural Sciences Westlake Institute for Advanced Study Hangzhou310024 China Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai200240 China

The quest for quantum materials with diverse symmetry-protected topological states has been the focus of recent research interest, primarily due to their fascinating physical properties and the potential technological utility. In this work, we report on the magnetotransport, de Haas-van Alphen (dHvA) oscillations, and the first-principles calculations of the stannide Cu3Sn that is isostructural with the recently reported topological semimetal Ag3Sn. The magnetoresistance was found to vary quasi-linearly in field. Clear dHvA oscillations were observed under a field as low as 1 Tesla at 2 K, with three major oscillation frequencies Fα=8.74 T, Fβ=150.19 T and Fγ=229.66 T and extremely small effective masses. The analysis of dHvA quantum oscillations revealed a possible nonzero Berry phase, suggestive of the nontrivial band topology. The corroborating evidence for the nontrivial electronic topology also comes from the first-principles calculations which yield a nonzero 2 topological index. These results collectively suggest that Cu3Sn, in analogy to its homologue Ag3Sn, may be another intermetallic stannide hosting topological Dirac fermions. Copyright © 2022, The Authors. All rights reserved.

关键词： Copper alloys

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Active disturbance rejection control design with suppression of sensor noise effects in application to DC-DC buck power converter

arXiv

引用

arXiv 2020年

作者： Lakomy, Krzysztof Madonski, Rafal Dai, Bin Yang, Jun Kicki, Piotr Ansari, Maral Li, Shihua The Poznaá Universitńy of Technology Poznan60-965 Poland The Energy Electricity Research Center International Energy College Jinan University Zhuhai519070 China The School of Automation Southeast University Key Laboratory of Measurement and Control of CSE Ministry of Education Nanjing210096 China The Institute of Robotics and Machine Intelligence Poznań University of Technology Poznań60-965 Poland The Faculty of Engineering and Information Technology University of Technology Sydney SydneyNSW2007 Australia

The performance of active disturbance rejection control (ADRC) algorithms can be limited in practice by high-frequency measurement noise. In this work, this problem is addressed by transforming the high-gain extended state observer (ESO), which is the inherent element of ADRC, into a new cascade observer structure. Set of experiments, performed on a DC-DC buck power converter system, show that the new cascade ESO design, compared to the conventional approach, effectively suppresses the detrimental effect of sensor noise over-amplification while increasing the estimation/control performance. The proposed design is also analyzed with a low-pass filter at the converter output, which is a common technique for reducing measurement noise in industrial applications. Copyright © 2020, The Authors. All rights reserved.

关键词： Spurious signal noise

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Analytical form of Fisher information matrix of bipoloar-activation-function-based multilayer perceptrons

Analytical form of Fisher information matrix of bipoloar-act...

引用

International Joint Conference on Neural Networks (IJCNN)

作者： Weili Guo Liping Xie Zhenyong Fu Jianhui Guo Guochen Pang Jian Yang PCA Lab Key Lab of Intelligent Perception and Systems for High-Dimensional Information of Ministry of Education Nanjing University of Science and Technology Nanjing P.R. China Key Laboratory of Measurement and Control of CSE Ministry of Education School of Automation Southeast University Nanjing P.R. China School of Automation and Electrical Engineering Linyi University Linyi P.R. China

ISBN: (数字)9781728169262

ISBN: (纸本)9781728169279

For the widely used multilayer perceptrons (MLPs), the existed singularities in the parameter space have seriously affected the learning dynamics of MLPs, which cause several singular learning behaviors. Since the Fisher information matrix (FIM) plays a significant role in analyzing the singular learning dyanmics of MLPs, it is very worthy to obtain the analytical form of FIM to do further investigation. In this paper, by choosing the bipolar error function as the activation function, the analytical form of FIM are obtained, where the validity of the obtained results are verified by taking three experiments.

关键词： Training Analytical models Multilayer perceptrons Indexes Mathematical model Standards

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A Novel Learning Method for Electric Circuit Course

A Novel Learning Method for Electric Circuit Course

引用

第一届计算机科学与教育信息化国际会议

作者： Xufeng Zhao Xiangyang Mu Yaming Zhang School of Electronic Engineering Xi'an Shiyou University School of Electrical Engineering Shaanxi University of Technology Shaanxi key Laboratory of Measurement and Control Technology for Oil and Gas Wells School of Electronic Engineering Xi'an Shiyou University Key Laboratory of Education Informalization for Nationalities Ministry of Education Yunnan Normal University

ISBN: (纸本)9781728123097

In recent years, with the rapid development of mobile Internet technology and intelligent mobile terminal equipment, mobile learning has been widely used in various teaching modes and attained good teaching effectiveness. By introducing the mobile learning mode into the electric circuit teaching in universities and combining with the traditional teaching mode, this paper discussed the notion of the application of Wechat platform to create a learning environment. Then elaborated the designing of mobile learning environment mode and the evaluation mechanism of learning effectiveness, and finally presented and analyzed the data obtained from the new teaching mode. Through nearly three years of application of the mode into the teaching for students majoring in electric automation, the mobile learning effectiveness has become gradually outstanding, compared with the learning method applied in the traditional teaching mode. The number of the students involved in mobile learning in the past three years has increased from 60% to 96.75,%. And the passing rate has risen from 50% to 86.7%. In general, the new teaching methodology has become popular with the students.

关键词： Mobile learning Wechat platform teaching effectiveness learning effectiveness evaluation mechanism

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Nonlinear Virtual Inertia control of WTGs for Enhancing Primary Frequency Response and Suppressing Drive-Train Torsional Oscillations

arXiv

引用

arXiv 2020年

作者： Liu, Bi Huang, Qi Zhao, Junbo Milano, Federico Zhang, Yingchen Sichuan Provincial Key Lab of Power System Wide-area Measurement and Control University of Electronic Science and Technology of China Chengdu Sichuan611731 China Department of Electrical and Computer Engineering Mississippi State University StarkvilleMS39762 United States School of Electrical and Electronic Engineering University College Dublin Dublin Ireland National Renewable Energy Laboratory GoldenCO80401 United States

Virtual inertia controllers (VICs) for wind turbine generators (WTGs) have been recently developed to compensate the reduction of inertia in power systems. However, VICs can induce low frequency torsional oscillations of the drive train of WTGs. This paper addresses this issue and develops a new nonlinear VIC based on objective holographic feedbacks theory. This approach allows transforming the original nonlinear control into a completely controllable system of Brunovsky’s type. Simulation results under various scenarios demonstrate that the proposed method outperforms existing VICs in terms of suppression of low frequency drive-train torsional oscillations, enhancement of system frequency nadir as well as fast and smooth recovery of WTG rotor speed to the original MPP point before the disturbance. The proposed method is also able to coordinate multiple WTGs. Copyright © 2020, The Authors. All rights reserved.

关键词： Frequency response

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Position tracking control of magnetic levitation system based on continuous sliding mode control*

Position tracking control of magnetic levitation system base...

引用

Chinese Automation Congress (CAC)

作者： Lei Zhao Linjie Chen Junxiao Wang Li Yu College of Information Zhejiang University of Technology Hangzhou China Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education School of Automation Southeast University Nanjing Chian

In this paper, aiming at the problem of position tracking control of magnetic levitation system under parameter uncertainties and unknown external disturbance, a continuous sliding mode control(CSMC) method based on extended state observer(ESO) is proposed. Firstly, in order to suppress the adverse effects of disturbance and system unmeasurable states on control performance, an ESO for the system was designed to estimate system disturbances and unmeasured states. Meanwhile, in order to improve the robustness of the system and eliminate the chattering phenomenon caused by the high-frequency switching function in the sliding mode control law, a position tracking controller based on continuous sliding mode control is designed. Then combined with disturbance estimation technology and continuous sliding mode control technology, a composite position tracking controller(CSMC+ESO) is designed for the magnetic levitation system. Simulation and experimental results shows that compared with the general continuous sliding mode control(CSMC), the proposed control method improves the tracking accuracy, convergence rate, obtain better anti-interference capability and noise filtering performance for control input.

关键词： Magnetic levitation Observers Sliding mode control Mathematical model Uncertain systems Robustness

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First-principles study of bulk and two-dimensional structures of the AMnBi family of materials (A=K,Rb,Cs)

引用

Physical Review B 2020年第3期102卷 035444-035444页

作者： Ziming Zhu Chunyan Liao Si Li Xiaoming Zhang Weikang Wu Zhi-Ming Yu Rui Yu Wei Zhang Shengyuan A. Yang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal University Changsha 410081 China Research Laboratory for Quantum Materials Singapore University of Technology and Design Singapore 487372 Singapore School of Materials Science and Engineering Hebei University of Technology Tianjin 300130 China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems and School of Physics Beijing Institute of Technology Beijing 100081 China School of Physics and Technology Wuhan University Wuhan 430072 China Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and Energy Fujian Normal University Fuzhou 350117 China School of Physics and Technology Center for Quantum Transport and Thermal Energy Science Nanjing Normal University Nanjing 210023 China

Magnetic materials with high mobilities are intriguing subjects of research from both fundamental and application perspectives. Based on first-principle calculations, we investigate the physical properties of the already synthesized AMnBi (A=K, Rb, Cs) family materials. We show that these materials are antiferromagnetic (AFM), with Néel temperatures above 300 K. They contain AFM ordered Mn layers, while the interlayer coupling changes from ferromagnetic (FM) for KMnBi to AFM for RbMnBi and CsMnBi. We find that these materials are narrow gap semiconductors. Owing to the small effective mass, the electron carrier mobility can be very high, reaching up to 105cm2/(Vs) for KMnBi. In contrast, the hole mobility is much suppressed, typically lower by two orders of magnitude. We further study their two-dimensional (2D) single layer structures, which are found to be AFM with fairly high mobility ∼103cm2/(Vs). Their Néel temperatures can still reach room temperature. Interesting, we find that the magnetic phase transition is also accompanied by a metal-insulator phase transition, with the paramagnetic metal phase possessing a pair of nonsymmorphic-symmetry-protected 2D spin-orbit Dirac points. Furthermore, the magnetism can be effectively controlled by the applied strain. When the magnetic ordering is turned into FM, the system can become a quantum anomalous Hall insulator with gapless chiral edge states.

关键词： Edge states First-principles calculations Magnetic phase transitions Spin-orbit coupling Topological materials Transport phenomena

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Active Support control Strategy of VSG-based PMSG with DC-Convergence Under Master-slave control

Active Support Control Strategy of VSG-based PMSG with DC-Co...

引用

International Conference on Power Electronics and Motion control (IPEMC)

作者： Liang Wang Yu-heng Yan Xiao-yang He Wei-chun Ge Chuang Liu Yu-tong Liu Power dispatching control center State Grid Liaoning Electric Power Co. Ltd. Shenyang China School of Electrical Engineering Northeast Electric Power University Jilin China Ministry of science and technology communication State Grid Liaoning Electric Power Co. Ltd. Shenyang China

ISBN: (数字)9781728153018

ISBN: (纸本)9781728153025

In order to provide the system with the inertia support through wind turbine rotor kinetic energy when the power of the power system fluctuates, the virtual synchronous generator (VSG) control strategy is adopted to the grid-connected inverter of the permanent magnet synchronous generator (PMSG), which can actively adjust the imbalance power caused by the system fluctuations, and provide the system with inertia support at the initial stage of system disturbance. And meanwhile a new parallel control method is proposed for wind turbines in this paper. The master-slave control strategy is adopted by the wind turbine machine-side converter, which can realize the collection and transmission of DC power, and reduce the number of inverters, save economic costs and avoid many problems caused by the connection of AC power. Finally, the performance and effectiveness of the proposed method are validated by the simulation results.

关键词： Simulation Rotors Master-slave Synchronous generators Inverters Wind turbines Voltage control

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Identification of motor parameters and improvement of voltage error for improvement of back-emf estimation in sensorless control of low speed operation

引用

Transactions of the Korean Institute of Electrical Engineers 2018年第5期67卷 635-643页

作者： Kim, Kyung-Hoon Yun, Chul Cho, Nae-Soo Jang, Min-Ho Kwon, Woo-Hyen School of Electronics Engineering Kyung-pook National University Korea Republic of Development Center Control Technology Control Technology Team 3 Doosan Machine Tools Korea Republic of Dept. of Electronics and Data Communication Keimyung College University Korea Republic of H and A Control R and D Lab. LG Electronics Korea Republic of

This paper propose a method to identify the motor parameters and improve input voltage error which affect the low speed position error of the back-emf(back electromotive force) based sensorless algorithm and to secure the operation reliability and stability even in the case where the load fluctuation is severe and the start and low speed operation frequently occurs. In the model-based observer used in this paper, stator resistance, inductance, and input voltage are particularly influential factors on low speed performance. Stator resistance can cause resistance value fluctuation which may occur in mass production process, and fluctuation of resistance value due to heat generated during operation. The inductance is influenced by the fluctuation due to the manufacturing dispersion and at a low speed where the change of the current is severe. In order to find stator resistance and inductance which have different initial values and fluctuate during operation and have a large influence on sensorless performance at low speed, they are commonly measured through 2-point calculation method by 2-step align current injection. The effect of voltage error is minimized by offsetting the voltage error. In addition, when the command voltage is used, it is difficult to estimate the back-emf due to the relatively large distortion voltage due to the dead time and the voltage drop of the power device. In this paper, we propose a simple circuit and method to detect the voltage by measuring the PWM(Pulse Width Modulation) pulse width and compensate the voltage drop of the power device with the table, thereby minimizing the position error due to the exact estimation of the back-emf at low speed. The suitability of the proposed algorithm is verified through experiment. © The Korean Institute of Electrical Engineers.

关键词： Inductance

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