A Numerical Method to Reduce the Stray Magnetic Field Around the Asymmetrical Wireless Power Transfer Coils for Electric Vehicle Charging

Zhang Wenjie,Song Jiancheng,Lin Lingyan,Ren Hui,Zheng Lijun,Gao Yunguang,Song Yuan 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

Wireless power transfer (WPT) is becoming increasingly popular in stationary electric vehicle charging. Unfortunately, the adverse health eff ects due to the stray magnetic fi eld created by the WPT coils have increasingly caused concern. However, the traditional stray magnetic fi eld optimization design method based on fi nite element simulation is time-consuming and resource intensive. In this paper, a numerical method to reduce the stray magnetic fi eld around the asymmetrical wireless power transfer coils is proposed while maintaining the transmission power constant. The formulas of the stray magnetic fi eld around the WPT coils are derived, and the distribution characteristics of the stray magnetic fi eld are analyzed in detail. The stray magnetic fi eld around the asymmetrical wireless power transfer coils is optimized by the numerical method, and the number of the turns for the WPT coils corresponding to the minimum stray magnetic fi eld intensity is obtained. The eff ectiveness of the numerical method is verifi ed via the fi nite element analysis tool JMAG, and it is proved that the numerical method require less computational time than the fi nite element simulation. The experiments have also been carried out to evaluate the validity of the theoretical analysis.

An Adaptive Fault-tolerant Control Method for Robot Manipulators

Wenjie Zhang,Xiaohui Yang,Zhenghong Xu,Wei Zhang,Li Yang,Xiaoping Liu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.12

This paper presents a new method for adaptive continuous nonsingular fast terminal sliding mode control (ACNFTSMC) based on a novel structure-improved extended state observer (SIESO) for fault-tolerant control (FTC). In response to the initial peaking phenomenon in traditional ESO (TESO), which can severely degrade the accuracy and stability of the control system, The SIESO is designed to replace TESO to estimate the lump disturbances/faults. Besides, to address the problem of the unknown estimation error of ESO, an adaptive technique is applied to compensate for the observation error in real-time. To guarantee fast convergence and chattering-free, the CNFTSMC method is employed. Afterward, the stability and rapid convergence of the control system is demonstrated using Lyapunov theory. Finally, the simulation results verify the superiority of the proposed control strategy compared to the other existing advanced control techniques.

Bacterial Community Structure and Function Shift in Rhizosphere Soil of Tobacco Plants Infected by Meloidogyne incognita

Wenjie Tong(Wenjie Tong),Junying Li(Junying Li),Wenfeng Cong(Wenfeng Cong),Cuiping Zhang(Cuiping Zhang),Zhaoli Xu(Zhaoli Xu),Xiaolong Chen(Xiaolong Chen),Min Yang(Min Yang),Jiani Liu(Jiani Liu),Lei Yu 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.6

Root-knot nematode disease is a widespread and catastrophic disease of tobacco. However, little is known about the relationship between rhizosphere bacterial community and root-knot nematode disease. This study used 16S rRNA gene sequencing and PICRUSt to assess bacterial community structure and function changes in rhizosphere soil from Meloidogyne incognita-infected tobacco plants. We studied the rhizosphere bacterial community structure of M. incognita-infected and uninfected tobacco plants through a paired comparison design in two regions of tobacco planting area, Yuxi and Jiuxiang of Yunnan Province, southwest China. According to the findings, M. incognita infection can alter the bacterial population in the soil. Uninfested soil has more operational taxonomic unit numbers and richness than infested soil. Principal Coordinate Analysis revealed clear separations between bacterial communities from infested and uninfested soil, indicating that different infection conditions resulted in significantly different bacterial community structures in soils. Firmicutes was prevalent in infested soil, but Chloroflexi and Acidobacteria were prevalent in uninfested soil. Sphingomonas, Streptomyces, and Bradyrhizobium were the dominant bacteria genera, and their abundance were higher in infested soil. By PICRUSt analysis, some metabolism-related functions and signal transduction functions of the rhizosphere bacterial community in the M. incognita infection-tobacco plants had a higher relative abundance than those uninfected. As a result, rhizosphere soils from tobacco plants infected with M. incognita showed considerable bacterial community structure and function alterations.

Modeling and Analysis of Conducted EMI for a Modular Multilevel Converter

Zhang Bin,Chen Wenjie,Huang Lang,Zhang Jiao,Yang Xu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Currently, the modular multilevel converters (MMCs) based high voltage direct current (HVDC) transmission system have been widely applied due to its better characteristics, such as the stringent modular structure and good line-side behavior. This paper studies the conducted common mode electromagnetic interference (EMI) in MMC based HVDC system. As a matter of fact, interference sources are very complicated for large amounts of switches in large scale MMCs. This paper proposed a novel EMI model of MMC for the first time. Based upon that model, the influence of parasitic parameters of switches, the voltages stage of direct current side and the switching frequency on the leakage current are studied in detail. Useful information about the distribution of conducted interference both in time domain and in frequency domain can be acquired from the proposed model. Theoretical analysis and simulations demonstrated the proposed EMI model provides an intensively investigation and discussion for the conducted EMI in MMC based HVDC system.

The Impact of O2O Service Influencing Factors on Repurchase Intention

Zhang Wenjie,Taesoo Moon 한국경영정보학회 2019 한국경영정보학회 학술대회논문집 Vol.2019 No.5

Chemokine Signaling Pathway Involved in CCL2 Expression in Patients with Rheumatoid Arthritis

Lin Zhang,Changyi Li,Min Yu,Jiayin Deng,Xing Lv,Jun Liu,Yu Xiao,Wenjie Yang,Yuru Zhang 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.4

Purpose: Rheumatoid arthritis (RA) is an inflammatory joint disorder, the progressionof which leads to the destruction of cartilage and bone. Chemokines are involvedin RA pathogenesis. In this study, we investigated the chemokine signaling pathway associated with CCL2 in peripheral blood (PB) and synovial tissues (ST) of RA patients based on our previous work about chemokine signaling pathway involvedin the activation of CCL2 production in collagen-induced arthritis rat ST. Materials and Methods: Total RNA was isolated from PB leukocytes and synoviumof the knee joint in both RA patients and control populations. Real-time polymerasechain reaction was used to determine CCL4, CCR5, c-Jun, c-Fos, and CCL2 expressions. Serum level of CCL2 was assessed by enzyme-linked immunosorbent assay, and the production of CCL2 in ST was analyzed immunohistochemically. Results: The expressions of CCL4, CCR5, c-Jun, c-Fos, and CCL2 messenger RNA in RA patients were significantly higher than those in healthy controls, both in ST and on PB leukocyte. Serum CCL2 levels were elevated in RA patients. Histological examination of rheumatoid joints revealed extensive CCL2 expression in RA ST. Conclusion: CCL2, CCL4, c-Jun, c-Fos, and CCR5 may play an important role in the recruitment of PB leukocytes into the RA joints. These data provide evidence that the chemokine signaling pathway is involved in CCL2 expression in RA patient tissues, which may contribute to chronic inflammation associated with RA. Targetingthis signaling pathway may provide a novel therapeutic avenue in RA.

Optimal design of EMI filters for PV system based on parasitic parameter and stability analysis

Jiao Zhang,Wenjie Chen,Bin Zhang,Xiaomei Song,Hao Huang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Electromagnetic magnetic interference (EMI) issue has become one of the urgent problems to be solved in the photovoltaic (PV) inverter system. Therefore, it should not be ignored. In order to optimize the EMI filter design, high frequency characteristic of a PV system is studied in this paper. A conducted EMI model is proposed. The proposed model take into consider the influences of PV array parameters, DC side cable impedance, inverter parasitic capacitance and the unbalance of AC side impedance. Based upon that model, a passive EMI filter used for the DC side of a PV system is designed and fabricated. And the designing steps have been given thoroughly. To acquire the best performance of the filter, a stabilization analysis based on Routh criterion is also made. Finally, experimental results are presented to verify the efficient of the proposed EMI filter.

Design of Intelligent Window System Based on ZigBee

张,文洁,(Zhang Wenjie),张,燚,(Zhangyi),程琳(Chenglin),李青,嵩(Li Qingsong) 아시아사회과학학회 2022 International Science Research Vol.2 No.1

由于网络技术与电子技术的飞速发展, 智能家居系统已成为发展的必然趋势, 窗户作为一种必不可少的住宅结构, 但是普遍存在着功能单一的问题, 而基于ZigBee的智能窗户相较于传统窗户和窗帘, 可以根据外界光照强度、温度湿度、下雨等情况, 自动调节光线、防盗保护隐私等众多优点。本文主要介绍了基于ZigBee制作的自动控制窗户系统, 从而达到智能效果。 Due to the rapid development of network technology and electronic technology, smart home system has become an inevitable trend of development. As an essential residential structure, windows generally have the problem of single function. Compared with traditional windows and curtains, smart windows based on ZigBee can be based on external light intensity, temperature and humidity, rain and so on, Automatic light adjustment, anti-theft, privacy protection and many other advantages. This paper mainly introduces the automatic control window system based on ZigBee, so as to achieve intelligent effect.

Backstepping Sliding Mode Control Based on Extended State Observer for Robotic Manipulators with LuGre Friction

Zhenghong Xu,Xiaohui Yang,Wenjie Zhang,Wei Zhang,Liufang Zhang,Peter Xiaoping Liu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.6

In this paper, we propose a backstepping integral nonsingular fast terminal sliding mode control approach based on an extended state observer to the trajectory tracking control of robotic manipulators with LuGre friction. In order to improve convergence speed and tracking precision, an integral fast terminal sliding surface is introduced. An appropriate saturation function is designed in the control input to avoid singularity. An extended state observer is employed to estimate the uncertainties and disturbances, and they are compensated by the control laws, for which the chattering can be effectively eliminated. The backstepping method is used to design the control input of the system to ensure the globally asymptotic stability based on the Lyapunov criterion. In comparison with other control methods, simulation results show effectiveness and superiority of this proposed control scheme.

An Isolated Soft-Switching Bidirectional Buck-Boost Inverter for Fuel Cell Applications

Zhang, Lianghua,Yang, Xu,Chen, Wenjie,Yao, Xiaofeng The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.3

This paper presents a new isolated soft-switching bidirectional buck-boost inverter for fuel cell applications. The buck-boost inverter combines an isolated DC-DC converter with a conventional inverter to implement buck-boost DC-DC and DC-AC conversion. The main switches achieve zero voltage switching and zero current switching by using a novel synchronous switching SVPWM and the volume of the transformer in the forward and fly-back mode is also minimized. This inverter is suitable for wide input voltage applications due to its high efficiency under all conditions. An active clamping circuit reduces the switch's spike voltage and regenerates the energy stored in the leakage inductance of the transformer; therefore, the overall efficiency is improved. This paper presents the operating principle, a theoretical analysis and design guidelines. Simulation and experimental results have validated the characteristics of the buck-boost inverter.