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Eddy Loss Analysis and Parameter Optimization of the WPT System in Seawater
Zhang, Ke-Han,Zhu, Zheng-Biao,Du, Luo-Na,Song, Bao-Wei The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3
Magnetic resonance wireless power transfer (WPT) in the marine environment can be utilized in many applications. However, energy loss in seawater through eddy loss (EL) is another consideration other than WPT in air. Therefore, the effect of system parameters on electric field intensity (EFI) needs to be measured and ELs calculated to optimize such a system. In this paper, the usually complicated analytical expression of EFI is simplified to the product of frequency, current, coil turns, and a coefficient to analyze the eddy current loss (ECL). Moreover, as the calculation of ECL through volume integral is time-consuming, the equivalent eddy loss impedance (EELI) is proposed to help designers determine the optimum parameters quickly. Then, a power distribution model in seawater is conceived based on the introduction of EELI. An optimization flow chart is also proposed according to this power distribution model, from which a prototype system is developed which can deliver 100 W at 90% efficiency with a gap of 30 mm and a frequency of 107.1 kHz.
Eddy Loss Analysis and Parameter Optimization of the WPT System in Seawater
Ke-Han Zhang,Zheng-Biao Zhu,Luo-Na Du,Bao-Wei Song 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3
Magnetic resonance wireless power transfer (WPT) in the marine environment can be utilized in many applications. However, energy loss in seawater through eddy loss (EL) is another consideration other than WPT in air. Therefore, the effect of system parameters on electric field intensity (EFI) needs to be measured and ELs calculated to optimize such a system. In this paper, the usually complicated analytical expression of EFI is simplified to the product of frequency, current, coil turns, and a coefficient to analyze the eddy current loss (ECL). Moreover, as the calculation of ECL through volume integral is time-consuming, the equivalent eddy loss impedance (EELI) is proposed to help designers determine the optimum parameters quickly. Then, a power distribution model in seawater is conceived based on the introduction of EELI. An optimization flow chart is also proposed according to this power distribution model, from which a prototype system is developed which can deliver 100 W at 90% efficiency with a gap of 30 mm and a frequency of 107.1 kHz.
Zhang, Chuan-Jin,Tang, Yi,Han, Dong,Zhang, Hui,Zhang, Xiao,Wang, Ke The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.3
A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.
Ying Zhang,Yunrun Zhang,Jianyong Dong,Xiaoxia He,Min Qiao,Hans-Otto Baral,Ke-Qin Zhang,Zefen Yu 한국미생물학회 2016 The journal of microbiology Vol.54 No.1
A new species of Orbilia related to O. luteorubella is described mainly based on morphological characters of its asexual morph and molecular data. The sexual morph does not significantly differ from O. luteorubella, whereas the asexual morph obtained from its ascospore isolate resembles members of the non-predacious genus Dactylella, because it has fusiform phragmoconidia borne singly at the apex of conidiophores. Phylogenetic analysis showed that this strain clustered with a clade that included available strains of the O. luteorubella aggregate and was distant from all analysed Dactylella species. Within this clade, the new strain fell between species with filiform conidia and those of a Pseudotripoconidium anamorph. By combining morphological and phylogenetic analyses, we conclude that our isolate belongs to a new taxon. Pleomorphism of the new taxon is described and discussed.
Chuan-Jin Zhang,Yi Tang,Dong Han,Hui Zhang,Xiao Zhang,Ke Wang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.3
A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.
Stability Analysis of Closely Star-battened Member of Transmission Tower
Han Jun-ke,Zhang Chun-lei,Li Zhen-bao,Wang Xu-ming 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.3
Stability of the closely star-battened member of a power transmission tower were researched in this paper, a theoretical analysis was conducted for the buckling mode of the closely star-battened member by different plate batten arrangements. The analytical method of the buckling capacity on the closely star-battened member was proposed here considering an arrangement type of the plate batten and they are compared with the results of a full-scale test. The conclusions are follows: the flexuraltorsional buckling did not happened for the closely star-battened member; the flexural buckling need to be calculated only after the strength reduction factor was considered; the stability-bearing capacity of the closely star-battened member of the line-shape type batten is slightly less than that of the cross-shape type batten; the stability-bearing capacity of the closely star-battened member can be improved when the number of bolts in the plate batten increases in a suitable extent; and the stability-bearing capacity calculated and test results agree well with each other when the stability-bearing capacity analytical method of the closely star-battened member was used to analyze the full-scale test tower. The experimental results show the calculation method is reasonable.
Zhang, Ziyu,Tan, Jibo,Wu, Xinqiang,Han, En-Hou,Ke, Wei Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.9
Corrosion fatigue crack growth (FCG) behavior of 316LN stainless steel was investigated in high-temperature pressurized water at different temperatures, load ratios (R = K<sub>max</sub>/K<sub>min</sub>) and rise times (t<sub>R</sub>). The environmental assisted effect on FCG rate was observed when both the R and t<sub>R</sub> exceeded their critical values. The FCG rate showed a linear relation with stress intensity factor range (ΔK) in double logarithmic coordinate. The environmental assisted effect on FCG rate depended on the ΔK and quantitative relations were proposed. Possible mechanisms of environmental assisted FCG rate under different testing conditions are also discussed.
Analysis and preventive measures for spangle formation in antiveiling photoelectric glass
Ke Wang,Meilun Zhang,Zhenbo Cao,Shengyun Yang,Yu Han,Qiao Wang,Shaohua Li,Yang Zhang,Haifeng Lv,You Zhou,Jinsheng Jia 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.4
The effective region of Antiveiling Photoelectric Glass (AVG) has high transmittance for ultraviolet, visible and near-infraredlight. At the same time, a high-efficiency light absorption layer can be generated from the substrate outside the effective regionto eliminate stray light and improve the clarity of optical imaging. It is widely used in the fields of low-light night vision andspace optical imaging. However, the spangle in AVG will affect its optical properties and reduce the transmittance and opticaluniformity of the glass. In this paper, AVG was prepared by platinum crucible, and the morphology and size of spangle inAVG were observed by scanning electron microscope (SEM). The surface of the glass substrate containing the spangle wassprayed with carbon. The composition of the spangle and the glass substrate was analyzed by Energy Dispersive Spectroscopy(EDS) energy spectrum. The results showed that the main component of the spangle was Pt element. The valence state ofplatinum in the spangle was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the Pt element inthe spangle was mainly in the form of 0 valence and +2 valence. The mechanism and preventive measures of AVG platinumspangle were proposed.
( Zhiming Zhang ),( Jianqiu Wang ),( En-hou Han ),( Wei Ke ) 한국부식방식학회 2019 Corrosion Science and Technology Vol.18 No.1
To find proper lathe machining parameters for SA182 Grade 304 stainless steel (SS), six kinds of samples with different machining surface states were prepared using a lathe. Surface morphologies and microstructures of near surface deformed layers on different samples were analysed. Surface morphologies and chemical composition of oxide films formed on different samples in simulated primary water with 100 μg/L O<sub>2</sub> at 310 ℃ were characterized. Results showed that surface roughness was mainly affected by lathe feed. Surface machining caused grain refinement at the top layer. A severely deformed layer with different thicknesses formed on all samples. In addition to high defect density caused by surface deformation, phase transformation, residual stress, and strain also affected the oxidation behaviour of SA182 Grade 304 SS in the test solution. Machining parameters used for # 4 (feed, 0.15 mm/r; back engagement, 2 mm; cutting speed, 114.86 m/min) and # 6 (feed,0.20 mm/r; back engagement, 1 mm; cutting speed, 73.01 m/min) samples were found to be proper for lathe machining of SA182 Grade 304 SS.