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13 results on '"Huang, Xiancheng"'

8. Faulty Feeder Detection Based on Space Relative Distance for Compensated Distribution Network With IIDG Injections

Author

Song Qin, Chen Qiaoshan, Xiangjun Zeng, Yuanyuan Wang, and Huang Xiancheng

Subjects
Boosting (machine learning), Distribution networks, Computer science, Energy Engineering and Power Technology, Kalman filter, Current source, Symmetrical components, Control theory, Electromagnetic coil, Electrical and Electronic Engineering, MATLAB, Electrical impedance, computer, computer.programming_language
Abstract

To improve the accuracy of faulty feeder selection based on zero sequence current mutation, distribution networks with inverter-interfaced distributed generators (IIDGs) are analyzed in detail. It is found that the IIDGs cannot be completely equivalent to a positive sequence current source due to their boosting increments. Thereby, a more accurate IIDG current estimation model based on the Gauss-Seidel method that considers the control strategy at the moment of fault is established. Moreover, a real-time estimation algorithm is introduced for faulty feeder detection to adjust the compensation degree of the Petersen coil. On this basis, this paper proposes a novel faulty feeder detection approach using the zero-sequence current space relative distance between the increments of each feeder and an estimation of the faulty path generated by Kalman filtering (KAF). The feasibility of the proposed approach is demonstrated in both a PSCAD/EMTDC simulation and a MATLAB experimental laboratory. The test results indicate that the proposed approach can achieve a high speed when employed for different fault conditions.

Published
2021

10. Studies on stator single-line-to-ground faults protection for a Powerformer considering the winding electromotive force distribution

Author

Jun Liang, Yuanyuan Wang, Xiangjun Zeng, Chen Xiaoqiao, Yang Kong, Yongsheng Guo, Ying Liu, Yao Xu, and Huang Xiancheng

Subjects
Electromotive force, Stator, Computer science, 020209 energy, 020208 electrical & electronic engineering, Energy Engineering and Power Technology, 02 engineering and technology, Fault (power engineering), law.invention, Generator (circuit theory), Reliability (semiconductor), law, Control theory, Electromagnetic coil, 0202 electrical engineering, electronic engineering, information engineering, Sensitivity (control systems), Electrical and Electronic Engineering, Voltage
Abstract

The Powerformer is very different from a traditional generator in terms of the stator winding material, the winding process and the grid-connection schemes. Therefore, the electrical parameters of the stator winding and the distribution characteristics of the electrical fault component are considerably different from those of a conventional generator. If the traditional protection scheme of a generator is simply applied to a Powerformer, the reliability and sensitivity of the protection will be lowered. Therefore, this paper carefully analyzes the tooth width of a Powerformer, the flux density distribution of the tooth, and the distribution of the electromotive force (emf) between the segments of the winding. A distributed parameter model of a Powerformer is established by considering the emf distribution of the Powerformer windings. Accordingly, the zero-sequence fundamental voltage distribution caused by the emf distribution is analyzed. Then, a stator single-line-to-ground (SLG) relay protection scheme is proposed for the Powerformer. The scheme considers the influence of the emf distribution on the fault characteristics and improves the suitability of traditional zero-sequence fundamental voltage protection for the Powerformer. The simulation results show that the scheme has good sensitivity and reliability.

Published
2020

12. A simple method for preparing chelated calcium based on the black liquor generated by the pulp and paper industry.

Author

Yang, Guiting, Cheng, Donghong, Liu, Yan, Dongdong, Cheng, Zhang, Min, Zhao, Hongmeng, Sun, Yao, Huang, Songjun, Sao, Junfei, Xu, Ting, and Huang, Xiancheng

Subjects
SULFATE waste liquor, PAPER industry, CALCIUM, SCANNING electron microscopes, SILICATE cements (Dentistry), CHELATION
Abstract

A simple method for preparing chelated calcium from black liquor produced in the paper industry was studied. Various factors influencing the chelation rate of Ca2+ were studied, including the system pH, reaction temperature, reaction time, reaction solution ratio. The optimum reaction conditions are as follows: the system pH, reaction temperature, reaction solution ratio (V(CaCl2):m (Black liquor)) and time were 5.6, 25°C, 1:20 and 60 min, respectively. The maximum Ca2+ chelation rate was 88.75%. The characteristics of chelated calcium fertilizer in black liquor were studied by Fourier transform infrared, scanning electron microscope. The results indicated that the CaCl2 could be chelated by the black liquor from paper-making industry, and showed a high chelating rate. [ABSTRACT FROM AUTHOR]

Published
2019
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13. Characterization of the Microbial Community Structures, Soil Chemical Properties, and Enzyme Activity of Stellera chamaejasme (Thymelaeaceae) and Its Associated Forages in Alpine Grassland of Northwestern China.

Author

Jin H, Cheng J, Liu H, Yang X, Dai L, Huang X, Yan Z, Min D, Xu X, and Qin B

Subjects
Grassland, Soil chemistry, Rhizosphere, Soil Microbiology, China, Nitrogen, Thymelaeaceae, Microbiota
Abstract

The invasion of toxic weeds was detrimental to the growth of original vegetation and speed up the degraded grasslands. The purpose of this study was to explore the difference in microbial community, soil physicochemical properties, and enzyme activity in the rhizosphere of Stellera chamaejasme and its associated forages (Stipa purpurea and Polygonum viviparum). The rhizosphere soil microbial communities of S. chamaejasme and its associated forages were determined by high-throughput sequencing technology, the physicochemical properties, and enzyme activities were also measured using soil chemical methods. We performed biological statistical analyses to explore the correlation of rhizosphere micro-ecological environment between the invading poisonous herb S. chamaejasme and its associated forages. The Ascomycota community in the rhizosphere soil of S. chamaejasme was significantly decreased when compared with its associated forages. S. chamaejasme and S. purpurea had a similar bacterial composition, while the rhizosphere of P. viviparum was associated with more Acidobacteria and Bacteroidetes. The RDA analysis showed S. chamaejasme had highly correlated with acid proteinase, invertase, polyphenol oxidase, cellulose, and neutral protease and S. purpurea had highly associated with N-acetyl-beta-D-glucosaminidase, β-D-Glucosidase, and the P. viviparum had highly associated with total phosphorus, total nitrogen, ammonium nitrogen, soil organic matter, pH, acid phosphatase, and catalase. Along with the invasion of S. chamaejasme, the microbial composition, soil physicochemical properties, and enzyme activity of the growing area changed considerably compared with the associated forages. Taken together, our results suggested that the composition and diversity of microbial communities associated with S. chamaejasme and its associated forages exhibited different patterns, and the rhizosphere soil microbial communities in different plants were regulated by different environmental factors in this alpine grassland ecosystem., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Published
2023
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