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Input-series hybrid dual active bridge DC-DC converter combined with LC resonant tank
Fu, Chao,Xu, Chongwei,Sun, Yuwei The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8
This paper presents an input-series hybrid dual active bridge (DAB) converter for efficiency improvement. The proposed converter is achieved by integrating a series resonant tank (SRT) into a single phase-shift (SPS) controlled DAB that shares one H-bridge at the secondary side. By using the super-resonant state of the LC tank, the phase correction of the secondary side H-bridge current can be obtained to realize zero voltage switching (ZVS), zero current switching (ZCS), and full load ZVS for the primary side bridges. In addition, the circulating current is reduced when compared to that of the traditional input-series DAB converter based on SPS control, which improves the overall efficiency. The system modelling and parameters design procedures are provided. Finally, a 1-kW experimental prototype was built, and the soft-switching performance was tested. The obtained results verify the effectiveness of the proposed topology and demonstrate a significant efficiency improvement.
Research and Validation of Pipe Acoustic Transmission Mechanism
Sun Fuchao,Pei Xiaohan,Zheng Lichen,Wang Guoqing,Jia Deli 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.11
During oil production an acoustic communication mode with downhole oil pipe as channel is one of feasible downhole control method. Based on a mechanism analysis, this paper presents a pipe acoustic transmission mechanism model. The model is derived to obtain a pipe dispersive equation. The simulation of phase velocity, group velocity and dispersion curves of three common oil pipes indicates that spectral distribution of longitudinal wave transmission in pipe presents a comb filter structure, and the passband/stopband distribution approximates periodicity and symmetry on spectrogram. The passband range, stopband range and amplitude value changes with length, cross area, density of oil pipe and joint. And the influence rule is given. Then the optimal frequency is suggested through simulation for downhole wireless communication tools design.
Deli Jia,Xiaohan Pei,He Liu,Fuchao Sun,Mingxin Zhao 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12
Integrated separate layer water injection technology is an effective approach to reduce the workload of injection oilfield. The primary equipment which consists of flowmeter, motor and control value is placed underground for a long time. Injection rate allocation fault diagnosis is a problem with character of multiformity. The fault symptoms and reasons are random, and it is hard to differentiate them. Weighted fuzzy C-means clustering algorithm combining symptoms signals and fuzzy mathematics approach is used on the technology. The algorithm is based on fuzzy C-means clustering algorithm, and increase weight to each fault sample to reduce the impact of samples on fault classifications. Simulation and analysis illustrates that the algorithm is able to reflect the real structure of the sample data. And it improves the accuracy of fault classification.
An efficient process for co-production of γ-aminobutyric acid and probiotic Bacillus subtilis cells
Hongbo Wang,Jinge Huang,Lei Sun,Fuchao Xu,Wei Zhang,Jixun Zhan 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.1
This study was to establish an integrated processfor the co-production of c-aminobutyric acid (GABA) andlive probiotics. Six probiotic bacteria were screened andBacillus subtilis ATCC 6051 showed the highest GABAproducingcapacity. The optimal temperature and initial pHvalue for GABA production in B. subtilis were found to be30 C and 8.0, respectively. A variety of carbon andnitrogen sources were tested, and potato starch and peptonewere the preferred carbon and nitrogen sources for GABAproduction, respectively. The concentrations of carbonsource, nitrogen source and substrate (sodium L-glutamate)were then optimized using the response surface methodology. The GABA titer and concentration of viable cells ofB. subtilis reached 19.74 g/L and 6.0 9 108 cfu/mL at120 h. The GABA titer represents the highest production ofGABA in B. subtilis. This work thus demonstrates a highlyefficient co-production process for GABA and probiotic B. subtilis cells.
Research of the Mechanism of Low Frequency Oscillation Based on Dynamic Damping Effect
Wenying Liu,Rundong Ge,Dandan Zhu,Weizhou Wang,Wei Zheng,Fuchao Liu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
For now, there are some low frequency oscillations in the power system which feature low frequency oscillation with positive damping and cannot be explained by traditional low frequency oscillation mechanisms. Concerning this issue, the dynamic damping effect is put forward on the basis of the power-angle curve and the study of damping torque in this article. That is, in the process of oscillation, damping will dynamically change and will be less than that of the stable operating point especially when the angle of the stable operating point and the oscillation amplitude are large. In a situation with weak damping, the damping may turn negative when the oscillation amplitude increases to a certain extent, which may result in an amplitude-increasing oscillation. Finally, the simulation of the two-machine two-area system verifies the arguments in this paper which may provide new ideas for the analysis and control of some unclear low frequency phenomena.
Research of the Mechanism of Low Frequency Oscillation Based on Dynamic Damping Effect
Liu, Wenying,Ge, Rundong,Zhu, Dandan,Wang, Weizhou,Zheng, Wei,Liu, Fuchao The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.4
For now, there are some low frequency oscillations in the power system which feature low frequency oscillation with positive damping and cannot be explained by traditional low frequency oscillation mechanisms. Concerning this issue, the dynamic damping effect is put forward on the basis of the power-angle curve and the study of damping torque in this article. That is, in the process of oscillation, damping will dynamically change and will be less than that of the stable operating point especially when the angle of the stable operating point and the oscillation amplitude are large. In a situation with weak damping, the damping may turn negative when the oscillation amplitude increases to a certain extent, which may result in an amplitude-increasing oscillation. Finally, the simulation of the two-machine two-area system verifies the arguments in this paper which may provide new ideas for the analysis and control of some unclear low frequency phenomena.
Huiwen Yan,Lei Sun,Jinge Huang,Yixing Qiu,Fuchao Xu,Riming Yan,Du Zhu,Wei Wang,Jixun Zhan 한국미생물학회 2018 The journal of microbiology Vol.56 No.11
A new type III polyketide synthase gene (Ssars) was discovered from the genome of Shiraia sp. Slf14, an endophytic fungal strain from Huperzia serrata. The intron-free gene was cloned from the cDNA and ligated to two expression vectors pET28a and YEpADH2p-URA3 for expression in Escherichia coli BL21(DE3) and Saccharomyces cerevisiae BJ5464, respectively. SsARS was efficiently expressed in E. coli BL21(DE3), leading to the synthesis of a series of polyketide products. Six major products were isolated from the engineered E. coli and characterized as 1,3-dihydroxyphenyl- 5-undecane, 1,3-dihydroxyphenyl-5-cis-6 -tridecene,1,3-dihydroxyphenyl- 5-tridecane, 1,3-dihydroxyphenyl-5-cis-8 - pentadecene, 1,3-dihydroxyphenyl-5-pentadecane, and 1,3- dihydroxyphenyl-5-cis-10 -heptadecene, respectively, based on the spectral data and biosynthetic origin. Expression of SsARS in the yeast also led to the synthesis of the same polyketide products, indicating that this enzyme can be reconstituted in both heterologous hosts. Supplementation of soybean oil into the culture of E. coli BL21(DE3)/SsARS increased the production titers of 1–6 and led to the synthesis of an additional product, which was identified as 5-(8 Z,11 Z-heptadecadienyl) resorcinol. This work thus allowed the identification of SsARS as a 5-alk(en)ylresorcinol synthase with flexible substrate specificity toward endogenous and exogenous fatty acids. Desired resorcinol derivatives may be synthesized by supplying corresponding fatty acids into the culture medium.
Research on Safety Monitoring and Warning System Based on Information Fusion for Coking Production
Nailu Zhang,Libo Li,Xin Liu,Yuzhe Zhang,Fuchao Li 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8
Coking production process is very complex, and full of risk factors, toxic and harmful substance, it’s a typical high risk industry. In view of the prominent safety hazards and strong interference to safety monitoring in coking production, put forward a kind of safety monitoring and warning system based on information fusion for coking production. To achieve the target that safety condition was monitored accurately and hazardous situation warned reliably, safety information of the monitoring and warning areas was collected by sensor network which include combustible gas sensor, dust sensor, temperature sensor, pressure sensor, flowmeter and IP camera ,and the information fusion model of safety monitoring and warning was established, and then, through the BP neural network and the D-S evidence theory algorithm, various safety information was fused. Actual tests show that it has achieved the goal that monitoring accurately and warning reliably. It is of great significance to ensure the security of coking production.
Lu Dezhi,Yang Yang,Zhang Pingping,Ma Zhenjiang,Li Wentao,Song Yan,Feng Haiyang,Yu Wenqiang,Ren Fuchao,Li Tao,Zeng Hong,Wang Jinwu 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.6
Spinal cord injury (SCI) is a disabling and destructive central nervous system injury that has not yet been successfully treated at this stage. Three-dimensional (3D) bioprinting has become a promising method to produce more biologically complex microstructures, which fabricate living neural constructs with anatomically accurate complex geometries and spatial distributions of neural stem cells, and this is critical in the treatment of SCI. With the development of 3D printing technology and the deepening of research, neural tissue engineering research using different printing methods, bio-inks, and cells to repair SCI has achieved certain results. Although satisfactory results have not yet been achieved, they have provided novel ideas for the clinical treatment of SCI. Considering the potential impact of 3D bioprinting technology on neural studies, this review focuses on 3D bioprinting methods widely used in SCI neural tissue engineering, and the latest technological applications of bioprinting of nerve tissues for the repair of SCI are discussed. In addition to introducing the recent progress, this work also describes the existing limitations and highlights emerging possibilities and future prospects in this field.