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Simulation study on an improved frequency-doubled triangular-shaped pulse train generator with reduced harmonic distortion

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Chinese Optics Letters 2014年第12期12卷 13-18页

作者：李晶宁提纲裴丽郑晶晶李月琴袁瑾王一群张婵陈宏尧 Key Lab of All Optical Network & Advanced Telecommunication Network of EMC Beijing Jiaotong University Institute of Lightwave Technology Beijing Jiaotong University

An approach to reducing the harmonic distortion in frequency-doubled triangular-shaped pulse train generation is proposed. It requires a dual-parallel Mach Zehnder modulator followed by a section of dispersive fiber, as the key component. The basic principle is to make the expression of optical intensity approximately equal to the Fourier expansion of idea triangular-shaped waveform. A detailed expression of the final optical intensity is given by theory and then verified by simulation. It is found that the impact of the undesired harmonic distortion is greatlv reduced.

关键词： Fiber optic sensors Frequency doublers harmonic analysis harmonic distortion Light modulators

harmonic distortion Modeling of Fully-BalancedThird-order Butterworth Gm-C Filter by a Block Diagram Approach

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Harmonic Distortion Modeling of Fully-BalancedThird-order Bu...

Model Predictive Current Control for Low-Cost Shunt Active Power Filter

2011 International Conference on Computer Science and Information Technology(ICCSIT 2011)

作者： Yingwu Miao Yuxing Zhang School of Electronic Engineering University of Electronic Science and Technology of China

ISBN: (纸本)9781612848334

Accurate distortion modeling of fully-balanced Gm-C filter is the main subject of this paper. Based on the phasor method, a block diagram approach was developed in this paper. To demonstrate the flexibility of this approach, a third-order Butterworth Gm-C filter was analyzed by using the proposed approach. A good agreement is shon between theoretical analysis and transistor level simulation by Spectre. The approach is suitable to be used in early steps of the design and it can give the designer a thorough understanding of the distortion of fully-balanced Gm-C filters.

关键词： harmonic distortion nonlinear distortion Gm-C filter block-diagram approach phasor method.

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1589-1598页

作者： Ali A.Abdel-Aziz Mohamed A.Elgenedy Barry W.Williams the Electronic and Electrical Engineering Department Strathclyde UniversityGlasgowG11XQUK School of Computing Engineering and the Built Environment(SCEBE)Glasgow Caledonian UniversityGlasgowG40BAUK

Performance of a three-phase shunt active power filter(SAPF)relies on the capability of the controller to track the reference ***,designing an accurate current controller is crucial to guarantee satisfactory SAPF *** paper presents a model predictive current controller(MPCC)for a low-cost,four-switch,shunt active power filter for power quality improvement.A four-switch,B4,converter topology is adopted as an SAPF,hence offering a simple,robust,and low-cost *** addition,to further reduce overall cost,only two interfacing filter inductors,instead of three,are used to eliminate switching current *** proposed SAPF model MPCC is detailed for implementation,where simulation and experimental results validate effectiveness of the proposed control algorithm showing a 20%improvement in total harmonic distortion compared with a conventional hysteresis band current controller.

关键词： Four-switch converter harmonic distortion model predictive current control power quality shunt active power filter

Optimum Control Scheme of Output Voltage Based on Cascaded H-bridge DVR

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CSEE Journal of Power and Energy Systems 2020年第2期6卷 249-258页

作者： Fei Jiang Siju Cheng Chunming Tu Qi Guo Qing Li Cheng Chen School of Electrical and Information Engineering Changsha University of Science&TechnologyChangsha 410004China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Engineering Sciences and Mathematics LuleåUniversity of TechnologyLuleå97187Sweden

This study presents an optimum control scheme to maximize the output voltage level number of the cascaded Hbridge dynamic voltage restorer(CHB–DVR).The relationship between the modulation index and the output voltage level number is analyzed in *** compensation reference voltage value is adjusted with the voltage drop depth to obtain high-quality output voltage with an acceptable total harmonic ***,the modulation index remains within a certain range and thus meets the requirements of the maximum level number technique(MLNT).In addition,an improvement method based on the MLNT is proposed to achieve minimum active power absorption from a direct current link of the CHB–*** traditional in-phase compensation and optimum control strategies are implemented to analyze the output voltage quality for verifying the feasibility of the proposed *** and experimental results show the effectiveness of the proposed control scheme.

关键词： Compensation scheme DC-link voltage dynamic voltage restorer harmonic distortion

ADAPTIVE harmonic CANCELLATION APPLIED IN ELECTRO-HYDRAULIC SERVO SYSTEM WITH ANN

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Chinese Journal of Mechanical Engineering 2004年第4期17卷 628-630页

作者： YaoJianjun WuZhenshun HanJunwei YueDonghai SchoolofMechanicalandElectncalEngineering HarbinInstituteofTechnologyHarbin150001.China

The method for harmonic cancellation based on artificial neural network (ANN)is proposed. The task is accomplished by generating reference signal with frequency that should beeliminated from the output. The reference input is weighted by the ANN in such a way that it closelymatches the harmonic. The weighted reference signal is added to the fundamental signal such thatthe output harmonic is cancelled leaving the desired signal alone. The weights of ANN are adjustedby output harmonic, which is isolated by a bandpass filter. The above concept is used as a basis forthe development of adaptive harmonic cancellation (AHC) algorithm. Simulation results performedwith a hydraulic system demonstrate the efficiency and validity of the proposed AHC control scheme.

关键词： Dead zone Higher harmonic harmonic distortion Artificial neural network (ANN) Adaptive harmonic cancellation (AHC)

Resonance Active Damping and PCC Voltage Quality Improvement of DFIG System Connected to Parallel Compensated Grid

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Chinese Journal of Electrical Engineering 2018年第4期4卷 33-40页

作者： Yipeng Song Nian Heng Frede Blaabjerg Department of Energy Technology Aalborg UniversityAalborg East 9220Denmark College of Electrical Engineering Zhejiang UniversityHangzhou 310027China

Under the connection to a weak grid,the Doubly Fed Induction Generator(DFIG)based wind power system has potential risk from two operational *** first issue is the High Frequency Resonance(HFR)mode due to the impedance interaction between the DFIG system and the weak *** order to ensure safe and reliable operation of the DFIG system,it is necessary to implement effective active damping strategies to mitigate the *** second issue is low order voltage harmonic distortion at the Point of Common Coupling(PCC),where consequently the performance of other grid-connected devices may *** could be advantageous that the DFIG system is able to improve the voltage quality at PCC by eliminating the low order harmonic *** this paper,both of the above mentioned DFIG operational characters,i.e.,active damping of HFR and the improvement of voltage quality at PCC,will be achieved by implementing advanced control strategies in the Rotor Side Converter(RSC)and the Grid Side Converter(GSC)*** are provided to verify the proposed control strategies for DFIG system connected to a weak grid.

关键词： DFIG system weak grid High Frequency Resonance(HFR) harmonic distortion active damping

Performance Evaluation of Energy Meters Under Nonlinear Loads

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Journal of Shanghai Jiaotong university(Science) 2017年第2期22卷 133-138页

作者： GUL Mehr 邰能灵 MAHAR Mukhtiar Ahmed 黄文焘 LARIK Abdul Sattar Department of Electrical Engineering Shanghai Jiao Tong University Department of Electrical Engineering Balochistan University of Information Technology Engineering and Management Sciences (BUITEMS) Department of Electrical Engineering Mehran University of Engineering & Technology

Due to rapid advancements in power electronics, the utilization of electronically switched loads and nonlinear loads is increasing gradually in the electrical power system. These loads create problems of measuring instruments, when connected to the power distribution systems. In this paper, an experimental investigation has been carried out to analyze the performance of single-phase watt-hour (induction and electronic types) energy meters that are being used in Pakistan. The accuracy of the energy meters has been tested under different household nonlinear loads, at various power factors and also at different supply voltage levels. Power factor and total harmonic distortion (THD) of different household loads are also recorded in the experimental work. A hardware based experimental setup has been designed to perform the experimental work. The experimental results have been compared to Water and Power Development Authority (WAPDA) standards for energy meters. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

关键词： energy meter accuracy nonlinear loads experimental investigation harmonic distortion power factor

A Fully Differential Interface Circuit of Closed-loop Accelerometer with Force Feedback Linearization

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Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 18-23页

作者： Hong-Lin Xu Hong-Na Liu Chong He Liang Yin Xiao-Wei Liu Micro-Electromechanical System Center Harbin Institute of Technology Key Laboratory of Micro-Systems and Micro-Structures Manufacturing Ministry of Education

In this paper,a fifth-order fully differential interface circuit( IC) is presented to improve the noise performance for micromechanical sigma-delta( Σ-Δ) accelerometer. A lead compensator is adopted to ensure the stability of the closed-loop high-order system. A low noise capacitance detection circuit is described with a correlated-double-sampling( CDS) technique to decrease 1 /f noise and offset of the operational amplifier. This paper also proposes a self-test technique for the interface circuit to test the harmonic distortion. An electrostatic force feedback linearization circuit is presented to reduce the harmonic distortion resulting in larger dynamic range( DR). The layout of the IC is implemented in a standard 0. 6 μm CMOS technology and operates at a sampling frequency of 250 kHz. The interface consumes 20 mW from a 5 V supply. The post-simulation results indicate that the noise floor of the digital accelerometer is about- 140 dBV /Hz1 /2at low frequency. The sensitivity is 2. 5 V /g and the nonlinearity is 0. 11%. The self-test function is achieved with 98. 2 dB thirdorder harmonic distortion detection based on the electrostatic force feedback linearization.

关键词： sigma-delta accelerometer self-test harmonic distortion electrostatic force feedback linearization

Impact of welding equipment on power quality

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China Welding 2024年第3期33卷 44-51页

作者： Kovács Attila Molnár Judit Jármai Károly Institute of Physics and Electrical Engineering Department of Electrical and Electronic Engineering Institutional DepartmentUniversity of MiskolcMiskolc H3515Hungary Institute of Energy and Chemical Engineering University of MiskolcMiskolc H3515Hungary

In an industrial facility,many electrical consumers can affect the quality of ***,the freedom from interference sources of these devices and equipment can be crucial for quality and uninterrupted electricity *** welding equipment is also a possible source of *** electrical harmonic injections created by welding equipment into the electrical network can affect the operation of other consumers connected to the given distribution points and cause unjustified overheating and shutdowns of some network *** aim of the research is to analyse the current harmonic injection of welding equipment of different types and modes of operation connected to the internal distribution network of the industrial *** effectiveness of the active harmonic filter built into the welding equipment was also examined in the *** results showed that the built-in active harmonic filter of the DC045 laser welding equipment was ineffective because the total harmonic distortion(THD)was about three times the 8%allowed by IEEE 519−2022 *** current harmonic injection of MIG 320 and MM403 type welding equipment was more than five times the permissible value of 5%.The current harmonic distortion of the PLAS140 type plasma-jet cutter equipment was below the 5% value allowed in the standard,thus it complied with *** on the measurement results,it can be concluded that the use of protection against harmonics is also necessary for welding ***,proposals were made in the paper to reduce the effect of harmonics.

关键词： electrical transients harmonic distortion electrical network disturbances voltage breaks total harmonic distortion(THD)