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Transient synchronous stability analysis and enhancement control strategy of a PLL-based VSC system during asymmetric grid faults

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Protection and Control of Modern Power systems 2023年第2期8卷 304-320页

作者： Yi Luo Jun Yao Zhaoyang Chen Sen Huang Shiyue Chen Qi Zhang Zhentao Qin State Key Laboratory of Power Transmission Equipment and System Security and New Technology School of Electrical EngineeringChongqing UniversityChongqing 400044China State Grid Changzhou Power Supply Company Changzhou 2131261China

The stability of a voltage source converters(VSC)system based on phase-locked loop(PLL)is very important issue during asymmetric grid *** paper establishes a transient synchronous stability model of a dual-sequence PLL-based VSC system during low voltage ride-through by referring to the equivalent rotor swing equation of syn-chronous *** on the model,the synchronization characteristics of the VSC system under asymmetric grid faults are described,and the interaction mechanisms,as well as the transient instability phenomena of positive and negative sequence PLL during asymmetric faults are *** the equal area criterion,the influences of sequence control switching action,detection delay,and interaction between the positive and negative sequence PLL on the transient synchronous stability of the VSC system are analyzed,*** addition,a transient stabil-ity assessment criterion based on the critical fault clearance angle and time and an enhancement control strategy based on the improved positive and negative sequence PLL are ***,the analytical results are validated through simulation and experiments.

关键词： Voltage source converters(VSC) Asymmetric grid faults Dual-sequence PLL Transient synchronous

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The electromagnetic transient simulation acceleration algorithm based on delay mitigation of dynamic critical paths

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Energy Informatics 2025年第1期8卷 1-12页

作者： Guo, Qi Lu, Yuanhong Zhang, Jie Zhang, Jingyue Huang, Libin Guo, Haiping Guo, Tianyu Tu, Liang State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid Guangzhou510663 China National Energy Power Grid Technology R & D Centre Guangzhou510663 China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Guangzhou510663 China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou510663 China

The task scheduling problem based on directed acyclic graphs (DAGs) has been proven to be NP-complete in general cases or under certain restrictions. In this paper, building upon existing scheduling algorithms, we introduce a static task scheduling algorithm based on directed acyclic graphs. By incorporating the proportion of task transmission delay as a guiding metric in the optimization process, processors can be prioritized for tasks with high latency, thereby improving computational efficiency. We first validate the theoretical feasibility of the algorithm using a theoretical case study and illustrate the algorithmic effectiveness using two real case studies, direct current (DC) model and alternating current (AC) model respectively. The research indicates that the scheduling algorithm proposed in this paper achieves an average scheduling length improvement of over 1.2% compared to the Heterogeneous Earliest-Finish-Time algorithm (HEFT) in topologies with high latency tasks. Additionally, the experiments show that the HEFT algorithm consumes 39.85us and the EMT-DM algorithm consumes 38.29us during simulation using DC, and the HEFT algorithm consumes 31.23us and the EMT-DM algorithm consumes 26.51us during simulation using AC, both of which are improved compared to the HEFT algorithm. © The Author(s) 2025.

关键词： Flow graphs

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Design of Angle-stable and High-transmittance Frequency Selective Rasorber Based on Bilateral Connected Interdigital Resonator

Design of Angle-stable and High-transmittance Frequency Sele...

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2024 Photonics and Electromagnetics Research Symposium, PIERS 2024

作者： Xu, Yixuan Shi, Tongtong Hu, Xueyi Yan, Yuchen Wu, Weiwei National University of Defense Technology State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Changsha China

ISBN: (纸本)9798350375909

This paper presents a novel frequency selective rasorber (FSR) design with a highly transparent window. FSR is a two-dimensional periodic structure consisting of a lossless FSS layer, an air layer, and a lossy resistive thin layer. The lossless bandpass layer consists of a bimetallic square ring. It provides a bandpass response with double transmission zeros by parallel resonance. The impedance layer consists of bilaterally connected interdigital resonator (BCIR) and crossed metal wires loaded with resistors. Among them, the BCIR can produce parallel resonance. When the lossless layer coincides with the parallel resonance frequency of the lossy layer, the FSR can produce a high transmittance window. The whole structure can produce a frequency response with low-frequency absorption and high-frequency transmission. The simulation results show that the structure has almost the same response under both TM and TE polarization conditions. the reflection coefficient of the FSR in the band of 5.03-11.61 GHz under TE polarization is below -10 dB. The transmission coefficient of the FSR in the 8.57-9.73 GHz band is higher than -3 dB, where the minimum insertion loss of the transmission window can reach -0.00652 dB near 9.12 GHz. Meanwhile, the FSR has good angular stability up to 40° angle of incidence. Finally, the equivalent circuit model (ECM) of FSR is also presented. © 2024 IEEE.

关键词： Equivalent circuits

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Impact of Revised Trigger and Closure of the Double-Plume Convective Parameterization on Precipitation Simulations over East Asia

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Advances in Atmospheric Sciences 2023年第7期40卷 1225-1243页

作者： Xiaohan LI Yi ZHANG Yanluan LIN Xindong PENG Baiquan ZHOU Panmao ZHAI Jian LI State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China 2035 Future Laboratory PIESAT Information Technology Co Ltd.Beijing 100195China Department of Earth System Science Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China CMA Earth System modeling and Prediction Center Beijing 100081China

A double-plume convective parameterization scheme is revised to improve the precipitation simulation of a global model(Global-to-Regional Integrated Forecast system;GRIST).The improvement is achieved by considering the effects of large-scale dynamic processes on the trigger of deep *** closure,based on dynamic CAPE,is improved accordingly to allow other processes to consume CAPE under the more restricted convective trigger *** revised convective parameterization is evaluated with a variable-resolution model setup(110–35 km,refined over East Asia).The Atmospheric Model Intercomparison Project(AMIP)simulations demonstrate that the revised convective parameterization substantially delays the daytime precipitation peaks over most land areas,leading to an improved simulated diurnal cycle,evidenced by delayed and less frequent afternoon ***,changes to the threshold of the trigger function yield a small impact on the diurnal amplitude of precipitation because of the consistent setting of dCAPE-based trigger and *** simulated mean precipitation remains reasonable,with some improvements evident along the southern slopes of the Tibetan *** revised scheme increases convective precipitation at the lower levels of the windward slope and reduces the large-scale precipitation over the upper slope,ultimately shifting the rainfall peak southward,which is in better agreement with the observations.

关键词： convective parameterization diurnal cycle of precipitation East Asia variable-resolution modeling

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In-flight performance analysis of the navigation augmentation payload on LEO communication satellite:a preliminary study on WT01 mission

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Geo-Spatial Information Science 2022年第1期25卷 88-103页

作者： Ziqian Wu Baoguo Yu Chuanzhen Sheng Jingkui Zhang Song Xie Cailun Wu State Key Laboratory of Satellite Navigation System and Equipment Technology ShijiazhuangChina The 54th Research Institute of China Electronics Technology Group Corporation ShijiazhuangChina

With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation *** by volume,weight,power consumption,and running time,the in-flight performance of navigation augmentation payload remains to be *** this paper,we analyze the data quality of on-board GNSS observation and evaluate the precision of short-arc dynamic Precise Orbit Determination(POD)performance based on the WangTong-01(WT01)***,the downlink navigation measurement data of WT01 satellites are analyzed and compared with the GNSS *** results show that the average multipath errors of the WT01 on-board GPS L1,L2 and BeiDou Satellite Navigation system(BDS)B1,B2 code observation are 0.54,0.74,0.65,and 0.58 m,*** short-arc dynamic POD three-dimensional(3D)overlapping accuracy is 7.1 *** average multipath errors of downlink navigation signal Z1 and Z2 are 0.81 and 0.80 m,respectively,which at the same order of magnitude as GNSS *** maximum Carrier-to-Noise Ratio(C/N0)value of WT01 downlink measurement data can reach 60 dB Hz,which is much stronger than GNSS and indicates the navigation signals of LEO satellites can meet the basic requirement of navigation augmentation.

关键词： Navigation payload in-flight performance augmentation communication satellites LEO

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Design and Validation of Maintenance system for Space Manipulator Grapple Fixture 14

Design and Validation of Maintenance System for Space Manipu...

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14th International Conference on Reliability, Maintainability and Safety, ICRMS 2023

作者： Zeng, Lei Gao, Ben Zhu, Chao Hu, Chengwei Xiong, Minghua Beijing Key Laboratory of Intelligent Space Robotic System Technology and Applications Beijing Institute of Spacecraft System Engineering Beijing100094 China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin300458 China

ISBN: (纸本)9798350329988

The space manipulator plays an integral role in the assembly and construction of the China space station. The grapple fixture is positioned at designated locations on the space station as the foundation for the space manipulator. It is utilized in conjunction with the space manipulator to capture target objects and complete crawling tasks. The performance of the space manipulator is directly impacted by the grapple fixture, and a failure of the grapple fixture can even jeopardize the space station mission. This paper analyzed the maintenance requirements of the grapple fixture, proposed a maintenance system for it, and executed replacement tasks with the assistance of maintenance tools and astronauts in orbit. The feasibility of this approach is verified through ground testing and simulation analysis. The results will serve as a valuable reference and engineering guidance for future space manipulator maintenance. © 2023 IEEE.

关键词： Fixtures (tooling)

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Design and Experimental Validation of a Worm-Like Tensegrity Robot for In-Pipe Locomotion

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Journal of Bionic Engineering 2023年第2期20卷 515-529页

作者： Xiaolin Dai Yixiang Liu Wei Wang Rui Song Yibin Li Jie Zhao School of Control Science and Engineering Shandong UniversityJinan250061China Engineering Research Center of Intelligent Unmanned System of Ministry of Education Jinan250061China Shandong Research Institute of Industrial Technology Jinan250061China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin150080China

Traditional rigid-body in-pipe robots usually have complex and heavy structures with limited flexibility and *** soft in-pipe robots have great improvements in flexibility,they still have manufacturing difficulties due to their reliance on high-performance soft *** structure is a kind of self-stressed spatial structure consisting discrete rigid struts connected by a continuous net of tensional flexible strings,which combines the advantages of both rigid structures and soft *** applying tensegrity structures into robotics,this paper proposes a novel worm-like tensegrity robot for moving inside ***,a robot module capable of body deformation is designed based on the concept of tensegrity and its deformation performance is ***,the optimal parameters of the module are obtained based on the tensegrity *** deformation ability of the tensegrity module is tested ***,the worm-like tensegrity robot that can crawl inside pipes is developed by connecting three modules in *** performance and load capacity are tested on the prototype of the worm-like tensegrity robot by experiments of moving in horizontal pipe,vertical pipe,and elbow *** results demonstrate the effectiveness of the proposed design and suggest that the robot has high compliance,mobility,and adaptability although with simple structure and low cost.

关键词： Bio-inspired robot Soft robot application Tensegrity structure Pipe crawling

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In situ quantification of NO synthesis in a warm air glow discharge by WMS-based Mid-IR QCL absorption spectroscopy

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Plasma Science and technology 2022年第4期24卷 155-163页

作者： Chuanqi WANG Junjie QIAO Yijia SONG Qi YANG Dazhi WANG Qingyuan ZHANG Zhan SHU Qing XIONG State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044People's Republic of China

Nitric oxide(NO)is one of the most crucial products in the plasma-based nitrogen fixation *** this work,in situ measurements were performed for quantifying the NO synthesis spatially in a warm air glow discharge,through the method of Mid-infrared quantum cascade laser absorption spectroscopy(QCL-AS).Two ro-vibrational transitions at 1900.076 cm^(-1) and 1900.517 cm^(-1) of the ground-state NO(X)were probed sensitively by the help of the wavelength modulation spectroscopy(WMS)approach to increase the signal/noise(S/N)*** results show a decline trend of NO synthesis rate along the discharge channel from the cathode to the ***,from the point of energy efficiency,the cathode region is of significantly low energy efficiency of NO *** disproportionality was found for the high energy consumption but low NO production in the region of cathode area,compared to that in the positive column *** analysis demonstrates the high energy cost of NO production in the cathode region,is ascribed to the extremely high reduced electric field E/N therein not selectively preferable for the processes of vibrational excitation or dissociation of N_(2) and O_(2) *** drags down the overall energy efficiency of NO synthesis by this typical warm air glow discharge,particularly for the ones with short electrode *** of further improving the energy cost of NO synthesis by variations of the discharge operation conditions,such as discharge current or airflow rate,imply other effective manners able to tune the energy delivery selectively to the NO formation process,are sorely needed.

关键词： nitric oxide QCL absorption spectroscopy WMS energy efficiency warm air discharge

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Microstructure and Mechanical Properties of B-Bearing Austenitic Stainless Steel Fabricated by Laser Metal Deposition In-Situ Alloying

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Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 453-465页

作者： Sheng Huang Xiaoyu Zhang Dichen Li Qingyu Li State Key Laboratory for Manufacturing Systems Engineering Xian Jiaotong UniversityXian 710049China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

In the field repair application of laser metal deposition(LMD),the kinds of powder materials that can be used are limited,while the equipment components are made of various *** many components have to be repaired with heterogeneous ***,it is difficult to match the mechanical properties between the repaired layer and the substrate due to the diff erent *** on the high flexibility of raw materials and processes in LMD,an in-situ alloying method is proposed herein for tailoring the mechanical properties of LMDed *** diff erent mixing ratios of Fe314 and 316 L stainless steel powders as the control parameter,the microstructure and mechanical properties of B-bearing austenitic stainless steel fabricated by LMD in-situ alloying with diff erent proportions of Fe314 and 316 L particles were *** the increase in the concentration of 316 L steel,the volume fraction of the eutectic phase in deposited B-bearing austenitic stainless steel reduced,the size of the austenite dendrite increased,the yield strength and ultimate tensile strength decreased monotonically,while the elongation increased ***,the fracture mode changed from quasi-cleavage fracture to ductile *** adding 316 L powder,the yield strength,tensile strength,and elongation of deposited B-bearing austenitic stainless steel could be adjusted within the range of 712 MPa–257 MPa,1325 MPa–509 MPa,and 8.7%–59.3%,***,this work provides a new method and idea for solving the performance matching problem of equipment components in the field repair.

关键词： Additive manufacturing Laser metal deposition In-situ alloying B-bearing austenitic stainless steel Mechanical properties

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On Fast N-1 Contingency Analysis: A Graph Neural Network Approach 16

On Fast N-1 Contingency Analysis: A Graph Neural Network App...

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16th IEEE PES Asia-Pacific Power and Energy Engineering Conference, APPEEC 2024

作者： Tang, Ningkai Zhang, Tao Liu, Junjun Lu, Jixiang Yang, Weiyong State Grid Electric Power Research Institute State Key Laboratory of Technology and Equipment for Defense against Power System Operational Risks Nanjing China

ISBN: (纸本)9798350386127

Rapid N-1 contingency analysis is crucial for ensuring the stability and reliability of power systems, but traditional methods can be computationally prohibitive for large-scale grids. This paper proposes a novel approach leveraging graph neural networks (GNNs) to accelerate this process. By exploiting the inherent graph structure of power systems and the learning capabilities of GNNs, this study train specialized models to predict post-contingency branch flows for each credible N-1 contingency. This eliminates the need for repeated online power flow (PF) calculations, significantly reducing computational burden. Evaluation on the IEEE 118-bus test system demonstrates a remarkable 89.33% reduction in computation time compared to the Newton-Raphson (NR) method, while maintaining high accuracy exceeding 97% and outperforming other GNN architectures. This fast and accurate GNN-based approach promises to enable real-time contingency analysis and enhance situational awareness for improved grid resilience and operational decision-making. © 2024 IEEE.

关键词： Power system analysis

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