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Supplementary Control for Mitigation of Successive Commutation Failures Considering the Influence of PLL Dynamics in LCC-HVDC Systems

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CSEE Journal of Power and Energy Systems 2022年第3期8卷 872-879页

作者： Jun Lu Xiaoming Yuan Meiqing Zhang Jiabing Hu State Key Laboratory of Advanced Electromagnetic Engineering and Technology and the School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan430074China

Line commutated converter based high voltage direct current(LCC-HVDC)links are widely employed for long distance bulk power transmission and asynchronous alternating current(AC)grid ***,LCC-HVDC systems often suffer from commutation failures when AC voltage is distorted,oscillating or reduced by AC faults,which leads to overheating of converter valves and interruptions in transmitted *** of which can have an adverse impact on the safety and stability of the entire power *** paper proposes a supplementary control for mitigation of successive commutation failures on the basis of analyzing the influence of phase-locked loop(PLL)dynamics on the commutation *** analyzing the impact of PLL dynamics on the actual leading angle,it is found that changes in the AC voltage phase remarkably influence ***,the error between the AC voltage phase and PLL’s output angle is added to the output of the extinction angle or DC voltage control to mitigate the successive commutation failures of LCC-HVDC *** conducted on the CIGRE benchmark model in PSCAD/EMTDC validate the performance of the supplementary control,which effectively mitigates successive commutation failures.

关键词： Commutation failure dynamics LCC-HVDC mitigation PLL supplementary control

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electromagnetic interaction between local surface plasmon polaritons and an atmospheric surface wave plasma jet

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Chinese Physics B 2014年第3期23卷 404-411页

作者：陈兆权胡东刘明海夏广庆郑晓亮胡业林叶秋波陈明功祝龙记胡希伟 College of Electrical & Information Engineering Anhui University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology State Key Laboratory of Structure Analysis for Industrial Equipment Dalian University of Technology

We analyze the electromagnetic interaction between local surface plasmon polaritons （SPPs） and an atmospheric surface wave plasma jet （ASWPJ） in combination with our designed discharge device. Before discharge, the excitation of the SPPs and the spatial distribution of the enhanced electric field are analyzed. During discharge, the critical breakdown electric field of the gases at atmospheric gas pressure and the surface wave of the SPPs converted into electron plasma waves at resonant points are studied. After discharge, the ionization development process of the ASWPJ is simulated using a two- dimensional fluid model. Our results suggest that the local enhanced electric field of SPPs is merely the precondition of gas breakdown, and the key mechanism in maintaining the discharge development of a low-power ASWPJ is the wave-mode conversion of the local enhanced electric field at the resonant point.

关键词： surface wave plasma surface plasmon polaritons numerical simulation electromagnetic interac-tion

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Unveiling high-performance single-atom alloy catalysts for alkane dehydrogenation through DFT and machine learning synergy

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Journal of Catalysis 2025年 448卷

作者： Feng, Haisong Ge, Zhen Deng, Yuan Pu, Pengxin Zhao, Shiquan Song, Xin Yuan, Hao Wu, Yaze Yang, Jing Si, Yubing Politano, Antonio Zhang, Xin Zhang, Yong-Wei State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing100029 China 1 Fusionopolis Way #16-16 Connexis Singapore138632 Singapore College of Chemistry Pingyuan Laboratory Zhengzhou University Zhengzhou450001 China Department of Physical and Chemical Sciences University of L'Aquila Via Vetoio L'Aquila67100 Italy

The recent surge in shale gas production has renewed interest in efficient alkane dehydrogenation for the synthesis of fuels and high-value chemicals. However, developing cost-effective catalysts that exhibit high catalytic activity while minimizing over-dehydrogenation and carbon deposition remains a significant challenge. Here, we integrate density functional theory (DFT) calculations with machine learning (ML) to design single-atom alloy (SAA) catalysts for efficient alkane dehydrogenation. Using DFT, we calculate 92 C[sbnd]H bond disassociation energy barriers to construct a dataset, which is used to train eight ML algorithms with 12 features. The top-performing Bagging Regression (BAR) model is then employed to predict C[sbnd]H bond activation energy barriers on the surfaces of 53 SAA candidates, enabling rapid screening of methane dehydrogenation activity. Among these, the Ru1Cu SAA catalyst exhibits outstanding activity, outperforming pure Pt. Detailed DFT calculations confirm that Ru1Cu(111) not only exhibits superior performance in methane dehydrogenation, but also exceptional activity in the dehydrogenation of propane, ethane, and isobutane. Moreover, microkinetic simulations further confirm the high selectivity of the Ru1Cu(111) surface toward propylene during propane dehydrogenation. Feature engineering analyses reveal the critical roles of dehydrogenation steps and the surface energy of the single-atom metal in influencing C[sbnd]H bond activation. These findings underscore the effectiveness of the DFT–ML framework for catalyst discovery and highlight Ru1Cu SAA as a highly active, selective, and stable catalyst with strong resistance to over-dehydrogenation and carbon deposition, making it a highly promising candidate for alkane dehydrogenation. © 2025 Elsevier Inc.

关键词： Activation energy

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Centralized control of parallel connected power conditioning system in electric vehicle charge-discharge and storage integration station

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Journal of Modern Power Systems and Clean Energy 2015年第2期3卷 269-276页

作者： Jiuqing CAI Changsong CHEN Peng LIU Shanxu DUAN State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhanChina

This study presents a centralized control scheme that coordinates parallel operations of power conditioning system(PCS)for the grid interactions of electric vehicles(EVs)in EV charge-discharge and storage integration *** issues for the control and operation of PCS under various operation modes are discussed,including vehicle to grid(V2G)mode,stand-alone mode and seamless transfer *** intelligent multi-mode charge-discharge method is utilized for the V2G mode,and the parallel control method based on communication network is adopted for the standalone *** addition,a novel seamless transfer strategy is proposed,which is able to implement PCS transition between V2G mode and stand-alone *** detailed process of the seamless transfer between the two modes is *** results are presented to show the performance and feasibility of this strategy.

关键词： Centralized control Power conditioning system(PCS) Charge-discharge and storage integration station Vehicle to grid(V2G) Seamless transfer

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CHANNEL ACCESS PROTOCOLS FOR KU-BAND VSAT NETWORKS - A COMPARATIVE-EVALUATION

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IEEE COMMUNICATIONS MAGAZINE 1988年第5期26卷 34-44页

作者： RAYCHAUDHURI, D JOSEPH, K State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

The performance of candidate protocols for first-generation Ku-band very small aperture terminal (VSAT) satellite networks is compared. The goal is to assist the process of selecting a protocol. The performance comparison is carried out over a range of possible traffic, channel and satellite parameters, leading to an understanding of the appropriate regime for each of the protocols under consideration. The protocols considered are unslotted Aloha, slotted Aloha, selective-reject (SRE) Aloha, and demand-assigned time-division multiple-access (TDMA) or DAMA.< >

关键词： Access protocols Satellite broadcasting Costs Satellite ground stations Artificial satellites Time division multiplexing Local area networks Apertures Wide area networks Power generation economics

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A 30 mm Wide DC-Driven Brush-Shaped Cold Air Plasma Without Airflow Supplement

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Plasma Science and technology 2014年第4期16卷 329-334页

作者：陈兆权郑晓亮夏广庆李平胡业林杜志文祝龙记刘明海陈明功胡希伟 College of Electrical&Information Engineering Anhui University of Science and Technology State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

This paper reports a cold atmospheric pressure DC-driven air plasma brush. Three stainless steel needles are symmetrically mounted on a slot shaped PVC slab to act as the elec- trodes. The brush driven by a direct current （DC） power supply can generate an air plasma glow up to 30 mm wide with no inert gas addition and no air flow supplement. The plasma glow appears uniform no matter what kinds of material are processed. The measured current and the simulated current all show that each pulsed discharge including two peaks always oc- curs for different gaps between electrodes. Emission spectra measurement result shows that the obtained rotational temperatures are 300 K and the vibrational temperatures are 2250 K. Some reactive species are presented in the plasma glow, which suggest that the proposed plasma brush is beneficial to practical applications.

关键词： atmospheric pressure plasma cold plasma plume DC-driven discharge airplasma

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Semi-coherent and coherent nanoprecipitation induced superior strength-ductility combination in additively manufactured CoCrMoW alloy

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Journal of Materials Science & technology 2026年 242卷 1-14页

作者： Canjuan Xiao Weijin Cai Ruidi Li Song Ni Wenting Jiang Zhangwei Wang Khurram Yaqoob Zibin Chen Yi Huang Min Song State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China College of Materials and Advanced Manufacturing Hunan University of Technology Zhuzhou 412007 China School of Chemical and Materials Engineering National University of Sciences and Technology H-12 Islamabad Pakistan Research Institute for Advanced Manufacturing Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong 999077 China Department of Design and Engineering Faculty of Science and Technology Bournemouth University Poole Dorset BH12 5BB UK Materials Research Group Department of Mechanical Engineering University of Southampton Southampton SO17 1BJ UK

The interface coherence between precipitates and the matrix—whether coherent, semi-coherent, or incoherent—significantly impacts both the strength and ductility of metallic materials. An optimal balance between these properties can be achieved through manipulation of the precipitate/matrix interface. In this study, 1 wt.% and 2 wt.% TiN nanoparticles were introduced into a laser powder bed fusion (LPBF) fabricated CoCrMoW alloy as a reinforcing phase. Compared to the unreinforced alloy, the alloy with 1 wt.% TiN exhibited substantial improvements in yield strength, ultimate tensile strength, and fracture elongation, increasing from 876 MPa, 1190 MPa, and 15 % to 1071 MPa, 1421 MPa, and 17 %, respectively. Although the addition of TiN nanoparticles did not significantly affect the average grain size, it inhibited the formation of fine grains at the fusion line and influenced the overall grain size distribution. More importantly, the incorporation of TiN nanoparticles during the LPBF process led to the in-situ formation of semi-coherent precipitates rich in Ti and N, as well as coherent precipitates rich in Ti, N, and O. The semi-coherent precipitates, which exhibit well-defined orientation relationships and periodic misfit dislocations, enhanced strength by blocking stacking faults and ε laths. They also preserved plasticity by promoting self-relaxation through twinning at intersected areas, thus preventing crack nucleation at the interface. Furthermore, the chemical inhomogeneity between the coherent phase and the matrix increased resistance to dislocation cutting of the precipitates, thereby improving the material’s strength without compromising ductility.

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A Robust Deep Learning-Based DOA Super-Resolution Estimation Method With Single Snapshot

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IEEE Transactions on Vehicular technology 2025年

作者： Luo, Tao Chen, Peng Yang, Zihan Zheng, Le Zhang, Yudong Liu, Jun Southeast University State Key Laboratory of Millimeter Waves Nanjing210096 China Beijing Institute of Technology School of Information and Electronics Beijing100081 China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120 China University of Leicester School of Computing and Mathematical Sciences LeicesterLE1 7RH United Kingdom Army Engineering University of PLA National Key Laboratory on Electromagnetic Environment Effects and Electro-optical Engineering Nanjing210007 China

At present, deep learning (DL) has attracted widespread attention and has been widely applied in different areas of wireless communication, and signal processing. Due to its excellent feature extraction capability, it has been extensively used in the direction of arrival (DOA) estimation. In this paper, a robust network for super-resolution single-snapshot DOA estimation called DeepDOA is proposed. Different from other network-based DOA algorithms, DeepDOA takes the normalized real and imaginary parts of the received signal as inputs. Meanwhile, the network output is a vector instead of a spatial spectrum, and the corresponding spatial spectrum can be obtained by a simple transformation, which makes the spectrum smoother. Moreover, a sparse constraint is first introduced into the loss function, which improves the accuracy of the algorithm. Numerical simulations are conducted to verify its excellent performance. Finally, a frequency-modulated continuous wave (FMCW) radar location system is built to validate the proposed algorithm. © 1967-2012 IEEE.

关键词： Frequency modulation

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Physical design of FEL injector based on the performance-enhanced EC-ITC RF gun

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Chinese Physics C 2014年第1期38卷 79-85页

作者：胡桐宁陈曲珊裴元吉李骥秦斌 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology National Synchrotron Radiation Laboratory University of Science and Technology of China

To meet the requirements of high performance THz-FEL （Free Electron Laser）, a compact scheme of FEL injector was proposed. A thermionic cathode was chosen to emit electrons instead of a photo-cathode with its complex structure and high cost. The effective bunch charge was improved to ~200 pC by adopting an enhanced EC-ITC （External Cathode Independently Tunable Cells） RF gun to extract micro-bunches; back bombardment effects were almost eliminated as well. Constant gradient accelerator structures were designed to improve energy to ~14 MeV, while the focusing system was applied for emittance suppressing and bunch state maintenance. The physical design and beam dynamics of the key components for the FEL injector were analyzed. Furthermore, start- to-end simulations with multi-pulses were performed using homemade MATLAB and Parmela. The results show that continual high brightness electron bunches with a low energy spread and emittance could be obtained stably.

关键词： RF gun EC-ITC beam dynamics LINAC FEL injector

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Distribution Dynamic Operating Security Space Characterization for Aggregation and Congestion Capacity Evaluation of Virtual Power Plant

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IEEE Transactions on Smart Grid 2025年

作者： Song, Meng Xu, Zekai Gao, Ciwei Yan, Mingyu Hu, Qinran Southeast University School of Electrical Engineering Nanjing210096 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan430074 China

Virtual power plant(VPP) can manage distributed energy resources (DERs) to serve the grid, which should satisfy the power flow constraints. However, the distribution system operator(DSO) monopolies system parameters and VPP cannot directly access them. To solve the coordination problem between distribution operation security and VPP management, the distribution dynamic operating security space (DOSS) is proposed to constrain the DER output power for VPP aggregation and congestion capacity evaluation. First, a hybrid fuzzy modeling method based on the distribution system security region is employed to characterize DOSS, and less information exchange between VPP and DSO is required. Data privacy is well respected, and the computational complexity is also reduced. Second, the enhanced opposite direction searching algorithm and the generalized credibility-based piecewise membership crisp method are applied to achieve DOSS's type-reduction and defuzzification for VPP aggregation. This clarifies distribution security risks on VPP through DOSS’s credibility levels. Finally, VPP congestion capacity is proposed to quantify security constraint impacts on the VPP aggregation capacity, which can help coordinate the VPP economic and DSO secure operations. Case studies demonstrate that the proposed methodology can effectively embed the distribution operation security constraints into VPP aggregation and show higher applicability and lower conservativeness than existing approaches. © 2010-2012 IEEE.

关键词： Sensitive data

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