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2025 International Conference on Electrical Automation and Artificial Intelligence, ICEAAI 2025

作者： Yang, Ruixiong Chen, Yong Zeng, Yingjie Gao, Shuping China Guangdong Power Grid Co. Ltd. DC Distribution Power Research Center Zhuhai519000 China College of Electrical and Control Engineer Xi'an University of Science and Technology Xi'an710054 China Xi'an Key Laboratory of Electrical Equipment Condition Monitoring and Power Supply Security Xi'an710054 China

ISBN: (纸本)9798331506797

To address the challenge of series arc fault detection in DC microgrid systems, this research proposes an arc fault diagnosis approach based on feature frequency extraction and kernel extreme learning machine (KELM). The arc fault characteristic frequency is chosen by means of the signal's variational mode decomposition (VMD) and Hilbert marginal spectrum (HMS) analysis. The singular value, sample entropy, and energy entropy of the modal component that corresponds to the eigenfrequency are computed in order to generate the eigenvector. Subsequently, the KELM is utilized for arc fault diagnosis. Experimental results demonstrate that the proposed method effectively extracts fault characteristics, achieving a recognition accuracy of 98.26% in arc fault diagnosis. © 2025 IEEE.

关键词： arc fault DC microgrid fault diagnosis Hilbert marginal spectrum kernel extreme learning machine

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Dielectric response, nonlinear electrical characteristics, and gradient defect distribution of (In3+, Nb5+) co-doped Bi2/3Cu3Ti4O12 ceramics

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Ceramics International 2025年

作者： Yang, Longhai Li, Kai Gao, Wenjie Wu, Fengjuan Zhang, Tao School of Electrical and Control Engineering Xi'an University of Science and Technology Shaanxi Xi'an710054 China Xi'an Key Laboratory of Electrical Equipment Condition Monitoring and Power Supply Security Xi'an710054 China School of Science Xi'an University of Science and Technology Shaanxi Xi'an710054 China

(In + Nb) co-doped Bi2/3Cu3Ti4O12 (BCTO) ceramics were prepared via conventional solid-state method. The cubic perovskite phase with dense microstructure and uniform dispersion of dopants was obtained. In3+ and Nb5+ substitution of Ti sites can simultaneously increase dielectric constant and reduce dielectric loss. And the nonlinearity coefficient and breakdown voltage also increased. The variable electrode experiments show that the dielectric constant of the ceramics at low-frequency was due to the contribution from surface barrier layer capacitors (SBLC). The complex impedance spectrum and current density-voltage characteristic curve show that the ceramic has a significant electrical heterostructure, and the barrier height calculation confirms that the barrier at the grain boundary of the ceramic is Schottky barrier. It is shown that the dielectric constant of the ceramic at mid-frequency comes from the contribution of internal barrier layer capacitors (IBLC). The X-ray photoelectron spectroscopy tests were carried out at various thicknesses of the ceramic, highlighting significant differences in elemental content and valence states between the surface and interior of the ceramic. In particular, more Bi and O elements were detected in the surface layer, whereas numerous Bi0, Cu+, and Ti3+ metal ions appeared in the interior of the ceramic. This gradient distribution of different valence ions, as well as the complex defect structure formed by these point defects, might be the main reason for the gradual increase in dielectric constant and the decrease in dielectric loss with the increase of In3+ and Nb5+ co-doping in the mid-frequency range. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Perovskite

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DC Microgrid Arc Fault Diagnosis Based on Feature Frequency Extraction and Kernel Extreme Learning Machine

DC Microgrid Arc Fault Diagnosis Based on Feature Frequency ...

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Electrical Automation and Artificial Intelligence (ICEAAI), International Conference on

作者： Ruixiong Yang Yong Chen Yingjie Zeng Shuping Gao China Guangdong Power Grid Co. Ltd. DC Distribution Power Research Center Zhuhai China College of Electrical and Control Engineer Xi'an University of Science and Technology Xi'an China Xi'an Key Laboratory of Electrical Equipment Condition Monitoring and Power Supply Security Xi'an China

ISBN: (数字)9798331506797

ISBN: (纸本)9798331506803

关键词： Fault diagnosis Accuracy Extreme learning machines Simulation Fault detection Microgrids Feature extraction Entropy Vectors Kernel

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Dynamic analysis of a concentrating photovoltaic/concentrating solar power (CPV/CSP) hybrid system

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Science China(Technological Sciences) 2019年第11期62卷 1987-1998页

作者： HAN Xue XU Chao PAN XinYu JU Xing DU XiaoZe Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of MOE North China Electric Power University

Concentrating photovoltaic/concentrating solar power(CPV/CSP)systems suffer from varying irradiation and extreme working *** this study,a dynamic physical model is developed for the CPV/CSP hybrid system to analyze the dynamic responses of several key parameters,such as the solar radiation saltation or linear variation to represent the typical weather *** results show that the hybrid system could rapidly reach the steady state in less than about 53 s after the solar radiation saltation increases or decreases by 10%.The response time reflects that the thermal hysteresis of the hybrid system is mainly determined by varying the outlet temperature of R134a from the solar thermal ***,when the solar radiation changes linearly,a lower gradient is beneficial to remit the thermal hysteresis of the hybrid system and improve the thermal stability,and the parameters could be treated as the steady state values with a gradient of less than 0.2 W m^-2 s^-***,the quasi-steady state model was used to analyze the all-day dynamic performance of the hybrid *** shows that the power output and the flow rate are directly related to the direct normal irradiance(DNI),while the outlet temperature of R134a vapor could be almost constant except for the starting and stopping periods.

关键词： concentrating photovoltaic concentrating solar power transient simulation solar radiation disturbance dynamic performance

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Arc fault detection method for DC microgrid based on multiple features 3

Arc fault detection method for DC microgrid based on multipl...

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2024 3rd International Conference on Energy Internet and power Systems, ICEIPS 2024

作者： Chen, Yong Yang, Ruixiong Zeng, Yingjie Gao, Shuping China Guangdong Power Grid Co. Ltd. DC Distribution Power Research Center Zhuhai519000 China College of Electrical and Control Engineer Xi'An University of Science and Technology Xi'an710054 China Xi'An Key Laboratory of Electrical Equipment Condition Monitoring and Power Supply Security Xi'an710054 China

DC microgrids can improve energy structure change and enhance the use of new energy sources. However, it is challenging to find series arcs in DC microgrid systems. In order to detect series arc faults in DC microgrids, this study suggests a multi-feature based approach. By calculating the standard deviation of the system arc current, the root mean square(RMS) of the d5 wavelet coefficients and the marginal spectral eigenfrequency amplitude, a triple fault criterion is constituted. Then the threshold comparison weighting method is utilized to achieve fault identification. Finally, the simulation verification of the triple-criteria-based DC microgrid fault arc detection method shows that the method proposed in this paper has good anti-interference and reliability. © Published under licence by IOP Publishing Ltd.

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Multi-objective Optimization Design and Experimental Investigation of Centrifugal Fan Performance

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1267-1276页

作者： ZHANG Lei WANG Songling HU Chenxing ZHANG Qian Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education North China Electric Power University

Current studies of fan performance optimization mainly focus on two aspects： one is to improve the blade profile, and another is only to consider the influence of single impeller structural parameter on fan performance. However, there are few studies on the comprehensive effect of the key parameters such as blade number, exit stagger angle of blade and the impeller outlet width on the fan performance. The G4-73 backward centrifugal fan widely used in power plants is selected as the research object. Based on orthogonal design and BP neural network, a model for predicting the centrifugal fan performance parameters is established, and the maximum relative errors of the total pressure and efficiency are 0.974% and 0.333%, respectively. Multi-objective optimization of total pressure and efficiency of the fan is conducted with genetic algorithm, and the optimum combination of impeller structural parameters is proposed. The optimized parameters of blade number, exit stagger angle of blade and the impeller outlet width are seperately 14, 43.9~, and 21 cm. The experiments on centrifugal fan performance and noise are conducted before and after the installation of the new impeller The experimental results show that with the new impeller, the total pressure of fan increases significantly in total range of the flow rate, and the fan efficiency is improved when the relative flow is above 75%, also the high efficiency area is broadened. Additionally, in 65% -100% relative flow, the fan noise is reduced. Under the design operating condition, total pressure and efficiency of the fan are improved by 6.91% and 0.5%, respectively. This research sheds light on the considering of comprehensive effect of impeller structrual parameters on fan performance, and a new impeller can be designed to satisfy the engineering demand such as energy-saving, noise reduction or solving air pressure insufficiency for power plants.

关键词： centrifugal fan impeller structural parameters optimization experimental investigation

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Determination of the Minimum Wave Speed for the Modelling of Ventilated Cavitation

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Chinese Physics Letters 2016年第11期33卷 78-81页

作者：陈婷张宇宁杜小泽 Key Laboratory of Condition Monitoring and Control for Power Plant Equipment(Ministry of Education) North China Electric Power University

Ventilated cavitation plays an important role on the drag reduction of underwater vehicles and surface ships. For the modelling of ventilated cavitation, the minimum speed of the pressure wave is a crucial parameter for the closure of the pressure-density coupling relationship. In this study, the minimum wave speed is determined based on a theoretical model coupling the wave equation and the bubble interface motion equation. The influences of several paramount parameters （e.g., frequency, bubble radius and void fraction） on the minimum wave speed are quantitatively demonstrated and discussed. Compared with the minimum wave speed in the traditional cavitation, values for the ventilated cavitation are much higher. The physical mechanisms for the above difference are briefly discussed with the suggestions on the usage of the present findings.

关键词： of is for Determination of the Minimum Wave Speed for the Modelling of Ventilated Cavitation in

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Kinetics for hydrogen production by methanol steam reforming in fluidized bed reactor

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Science Bulletin 2016年第5期61卷 401-405页

作者： Fuxiang Zhang Yingshuang Shi Lijun Yang Xiaoze Du Key Laboratory of Condition Monitoring and Control for Power Plant Equipment (North China Electric Power University) Ministry of Education

Hydrogen is one of the best energy *** bed reactor provides a promising approach for hydrogen production. To describe the hydrogen generating rate with methanol steam reforming in fluidized bed reactor quantitatively, dual-rate kinetic models of the reactions with exponent form were developed, including that of steam reforming reaction(SR) and decomposition reaction(DE).The reaction rate per unit mass of catalyst was related to partial pressures of components. The exponentials in kinetic equations were obtained by linear least-squares method based on the experimental data. The variance homogeneity test(F test) shows that the dynamic models are feasible with high accuracy, which can be used to predict the generating rate of hydrogen under different reaction temperatures and feed flow rates in fluidized bed reactor. The SR and DE activation energy obtained indicates that ESR\ EDE, which can explain the previous observation that the CO_2 selectivity decreased with the temperature increase.

关键词： Kinetics model Methanol steam reforming Hydrogen production Fluidized bed reactor

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Microstructure and corrosion properties of laser cladding MoNi based alloy coatings

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Science China(Technological Sciences) 2014年第5期57卷 980-989页

作者： LI XinZhi LIU ZongDe WANG YongTian Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education North China Electric Power University

Mo-based alloys are widely used for their excellent wear and corrosion resistance as well as high temperature ***-NiCrBSi and Mo-Ni alloy coatings were prepared on 1020 water wall tube by laser cladding technology in the present *** microstructure and phase compositions were analyzed by means of the scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS)and X-ray diffractometry(XRD).The corrosion properties of the coatings were evaluated by an electrochemical experiment at room temperature in 3.5 wt.%NaCl *** increasing content of Mo,the structure homogeneity in Mo-Ni coatings deteriorated,the grain size increased,the average hardness and the corrosion resistance declined,due to the more content of harmful *** to the Mo-Ni coatings,the overall performance was better for the Mo-NiCrBSi,which had the higher hardness contributed by the element B and Si as well as the better corrosion resistance due to the addition of Cr.

关键词： laser cladding Mo-Ni Mo-NiCrBSi corrosion resistance

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Ti-based composite coatings with gradient TiC_x reinforcements on TC4 titanium alloy prepared by laser cladding

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Science China(Technological Sciences) 2014年第7期57卷 1454-1461页

作者： LIU ShuNv LIU ZongDe WANG Yang YUE Peng Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education North China Electric Power University

TiCx-NiTi2/Ti cermet composite coatings C1 and C2 with gradient TiCx reinforcements were prepared on TC4 titanium alloy by laser cladding *** microstructure and phase compositions were analyzed by means of scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS)and X-ray diffraction(XRD)*** TiCx exhibited a dendritic microstructure,and homogeneously dispersed in the Ti-based matrix where NiTi2 was *** increasing ingredient supercooling,temperature gradient and cooling temperature,the dendrites displayed a finer morphology with longer primary trunks and intensified side branches in the dilution *** the smoothed,coarse columnar ones became dominant in the upper clad layer due to the repeated energy input during multi-track *** Vickers microhardness presented a linear change trend through the cross-sections,which well confirmed the gradient distribution of *** more TiCx,C1 presented higher hardness than C2.

关键词： laser cladding composite coating TiCx-NiTi2 titanium alloy microhardness

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