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2023 3rd International Conference on Power system and Energy Internet, PoSEI 2023

作者： Peng, Fang Gao, Houlei Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Shandong Jinan250061 China

Sympathetic inrush is a phenomenon caused by the energization of the neighboring unloaded transformer. It may cause current differential protection to operate in the wrong way. Due to the lack of a special and continuous identification method, this paper studies the inherent feature of the two transformers during sympathetic inrush. Then a substation-area current signal based on the feature is constructed and its characteristics are analyzed. The time-frequency energy of the current signal is extracted based on the synchrosqueezed wavelet transform (SWT) since the SWT can process the transient signals accurately. The extracted energy is taken as the basis of the identification criterion. The simulation results conducted by PSCAD/EMTDC software prove the accuracy and effectiveness of the proposed method. © Published under licence by IOP Publishing Ltd.

关键词： Wavelet transforms

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Transient Synchronous Stability Analysis and Assessment of PLL-Based VSC systems by Bifurcation Theory

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IEEE Transactions on Energy Conversion 2024年第2期40卷 1312-1324页

作者： Han, Miao Ma, Rui Zhan, Meng Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Wuhan430074 China Shandong University Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education School of Electrical Engineering Jinan250061 China

For the transient synchronous stability of phase-locked loop based voltage source converter grid-tied systems, the generalized swing equation (GSE) is believed as very important. In this paper, the GSE is studied deeply by bifurcation theory. For instance, the co-dimension-2 Bogdanov-Takens (BT) bifurcation is rigorously analyzed, and the formulations for three co-dimension-1 bifurcations near the BT bifurcation point including the generalized saddle-node, Hopf, and homoclinic bifurcations are explicitly obtained. Moreover, all Hopf bifurcations in the GSE have been theoretically proven to be subcritical by the normal form method. Therefore, after the Hopf and homoclinic bifurcations, two different types of basin of attraction occur widely including a closed loop surrounded by an unstable limit cycle and a fish- like pattern surrounded by the stable manifold of unstable equilibrium point (UEP), respectively. In addition, for the transient synchronous stability assessment after the homoclinic bifurcation, based on the linear approximation of the stable manifold of the UEP, an index for the distance between the stable equilibrium point and the approximated stability boundary is formulated. All these theoretical results are well verified and supported by numerical calculations and real-time simulations, making all previous phenomenal observations of the GSE stand on the solid foundation of rigorous mathematics. © 1986-2012 IEEE.

关键词： Phase locked loops

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Dehazing Network Based on U-Net Structure and Residual Block 41

Dehazing Network Based on U-Net Structure and Residual Block

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第41届中国控制会议

作者： Wenbo Zhang Haoze Li Han Sun Yongqiang Bai School of Automation Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Beijing Institute of Technology

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

With the development of deep learning technology,the dehazing method based on convolutional neural network has also developed ***,it still faces some problems such as incomplete dehazing and difficulty in detail *** at the problems,we propose a dehazing network based on U-Net structure and residual *** the down sampling process,we introduce the residual block of attention mechanism,which effectively improves the feature extraction and expression ability of the *** the middle part of the network,the smooth dilation convolution residual block is used to expand the receptive field of the network and improve the restoration effect of small *** the same time,we introduce a feature fusion mechanism based on attention mechanism,which can reduce the loss of information and weight the down-sampling features into intermediate *** the process of up sampling,the method of adding elements instead of feature stitching is used to reduce the number of parameters and realize the function of jump ***,dense convolution residual blocks are added to the jump connection between input and output to further improve the *** experimental results show that the PSNR of this method can reach 32.893,which is better than the existing methods.

关键词： Image Dehazing Residual Network Attention mechanism

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High-performance chiral all-optical OR logic gate based on topological edge states of valley photonic crystal

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Chinese Physics B 2023年第7期32卷 392-398页

作者：王晓蓉费宏明林瀚武敏康丽娟张明达刘欣杨毅彪肖连团 College of Physics Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China School of Science RMIT UniversityMelbourneVictoria 3000Australia

For all-optical communication and information processing,it is necessary to develop all-optical logic gates based on photonic structures that can directly perform logic ***-optical logic gates have been demonstrated based on conventional waveguides and interferometry,as well as photonic crystal ***,any defects in those structures will introduce high scattering loss,which compromises the fidelity and contrast ratio of the information *** on the spin-valley locking effect that can achieve defect-immune unidirectional transmission of topological edge states in valley photonic crystals(VPCs),we propose a high-performance all-optical logic OR gate based on a VPC *** tuning the working bandwidth of the two input channels,we prevent interference between the two channels to achieve a stable and high-fidelity *** transmittance of both channels is higher than 0.8,and a high contrast ratio of 28.8 dB is ***,the chirality of the logic gate originated from the spin-valley locking effect allows using different circularly polarized light as inputs,representing“1”or“0”,which is highly desired in quantum *** device’s footprint is 18μm×12μm,allowing high-density on-chip *** addition,this design can be experimentally fabricated using current nanofabrication techniques and will have potential applications in optical communication,information processing,and quantum computing.

关键词： topological photonics topological edge state valley photonic crystal all-optical logic gate

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Distributionally Robust Transmission Expansion Planning Considering Uncertainty of Contingency Probability

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Journal of Modern Power systems and Clean Energy 2022年第4期10卷 894-901页

作者： Weilun Wang Mingqiang Wang Xueshan Han Ming Yang Qiuwei Wu Ran Li Key Laboratory of Power System Intelligent Dispatch and Control Ministry of EducationShandong UniversityJinan 250002China Department of Electrical Engineering Technical University of DenmarkRegion HovedstadenDenmark

The outage of power system equipment is one of the most important factors that affect the reliability and economy of power *** is crucial to consider the influence of contingencies elaborately in planning *** this paper,a distributionally robust transmission expansion planning model is proposed in which the uncertainty of contingency probability is *** uncertainty of contingency probability is described by uncertainty interval based on the outage rate of single *** epigraph reformulation and Benders decomposition are applied to solve the proposed ***,the feasibility and effectiveness of the proposed model are illustrated on the IEEE RTS system and the IEEE 118-bus system.

关键词： Benders decomposition distributionally robust equipment outage rate transmission expansion planning

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Online Queue-Aware Service Migration and Resource Allocation in Mobile Edge Computing

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IEEE Transactions on Vehicular Technology 2025年第5期74卷 8063-8078页

作者： Du, An Jia, Jie Chen, Jian Wang, Xingwei Huang, Ming Northeastern University School of Computer Science and Engineering Engineering Research Center of Security Technology of Complex Network System Key Laboratory of Intelligent Computing in Medical Image Ministry of Education Shenyang110819 China Northeastern University School of Computer Science and Engineering Shenyang110819 China

Mobile edge computing (MEC) integrated with Network Functions Virtualization (NFV) helps run a wide range of services implemented by Virtual Network Functions (VNFs) deployed at MEC networks. This emerging paradigm offers flexible edge resource management for Internet Service Providers (ISPs) and improves service satisfaction of diverse applications. However, a critical challenge lies in processing extremely unpredictable and bursty traffic flow, especially in event-trigger sensing tasks. In this paper, we study queue-aware service migration and resource allocation in an MEC network, where different devices with different arrival patterns request different network services. To this end, we first formulate a novel long-term operation cost minimization problem subject to the stability of multiple queues by adopting a simultaneous migration scheme and determining resource allocation dynamically. To address the problem efficiently, we propose an online control framework to make decisions without any prior system information. We first adopt the Lyapunov optimization technique to decompose the long-term optimization problem into multi-per-slot subproblems. Then, we adopt a decoupled optimization algorithm based on the coordinate descent method and augmented Lagrangian method to solve the offline mixed integer non-linear programming (MINLP) subproblems. Extensive results reveal that the proposed online optimization framework can efficiently balance queue stability and cost consumption. © 1967-2012 IEEE.

关键词： Mobile edge computing

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Distributed Secondary control of DC Microgrids with Operation Loss Reduction 43

Distributed Secondary Control of DC Microgrids with Operatio...

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43rd Chinese control Conference, CCC 2024

作者： Qiu, Maoxiang Zhang, Zhicheng Zuo, Zhiqiang Wang, Yijing Tianjin University Tianjin Key Laboratory of Intelligent Unmanned Swarm Technology and System School of Electrical and Information Engineering Tianjin300072 China Key Laboratory of System Control and Information Processing Ministry of Education Shanghai200240 China

ISBN: (纸本)9789887581581

In DC microgrids, current sharing and voltage regulation are two main objectives for real-time control, while the operation loss reduction is typically achieved by steady-state optimization. However, the ratio of current sharing is generally determined by the result of the centralized optimization in the classical hierarchical control framework of DC microgrids. Such an issue brings insufficient capability in respond to the changes of photovoltaic power and stored energy in the solar-powered energy systems. To handle this, this work proposes a distributed control scheme for single-bus DC microgrids. Under the proposed controller, the objectives of current sharing, bus voltage regulation and the total operation loss (converter loss and line loss) reduction can be guaranteed simultaneously. Moreover, the constraints on line currents and bus voltage are tackled as well. Finally, simulations verify the performance of the proposed control scheme. © 2024 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Microgrids

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Application of Digital Twin in Power Equipment Operation and Maintenance 17th

Application of Digital Twin in Power Equipment Operation and...

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17th Annual Conference of China Electrotechnical Society, CES 2022

作者： Zhang, Keqi Chen, Jing Liang, Zhenguang Du, Zongzhan Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Shandong Province Jinan250061 China

ISBN: (纸本)9789819903566

At present, with the increasing complexity of power system, the continuous upgrading of power equipment and the continuous improvement of power grid voltage level, the operation and maintenance of power equipment has attracted more and more attention, and the requirements for its accuracy, real-time and visualization are higher and higher. Digital twin is an emerging technology that can perceive, simulate and predict the physical world. It integrates multi-physical, multi-scale and multi-disciplinary attributes, has the characteristics of real-time interaction and closed-loop feedback, and can realize the interaction and integration of the physical world and the information world. Its emergence and development provide a new idea for solving the problem of power equipment operation and maintenance. Firstly, this paper introduces the concept and characteristics of digital twinning, summarizes the application status of digital twinning in power system, discusses the key technologies needed to realize digital twinning of power equipment, and analyzes the feasibility and technical bottleneck. Finally, the development of digital twin and its application prospect in power system are prospected. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Maintenance

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Grid Strength Assessment Method for Evaluating Small-signal Synchronization Stability of Grid-following and Grid-forming Converters Integrated systems

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Journal of Modern Power systems and Clean Energy 2025年第1期13卷 55-65页

作者： Qianhong Shi Wei Dong Guanzhong Wang Junchao Ma Chenxu Wang Xianye Guo Vladimir Terzija Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education School of Electrical EngineeringShandong UniversityJinan 250061China Electric Power Research Institute State Grid Zhejiang Electric Power Co.Ltd.Hangzhou 310014China School of Engineering Newcastle UniversityNewcastle upon TyneUK

Oscillations caused by small-signal instability have been widely observed in AC grids with grid-following(GFL)and grid-forming(GFM)*** generalized short-circuit ratio is commonly used to assess the strength of GFL converters when integrated with weak AC systems at risk of *** paper provides the grid strength assessment method to evaluate the small-signal synchronization stability of GFL and GFM converters integrated ***,the admittance and impedance matrices of the GFL and GFM converters are analyzed to identify the frequency bands associated with negative damping in oscillation modes dominated by heterogeneous synchronization ***,based on the interaction rules between the short-circuit ratio and the different oscillation modes,an equivalent circuit is proposed to simplify the grid strength assessment through the topological transformation of the AC *** risk of sub-synchronization and low-frequency oscillations,influenced by GFL and GFM converters,is then reformulated as a semi-definite programming(SDP)model,incorporating the node admittance matrix and grid-connected device *** effectiveness of the proposed method is demonstrated through a case analysis.

关键词： Grid-following converter grid-forming converter grid strength assessment small-signal stability

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Mechanism and Methods for Fault Recovery of Grid-Forming Inverter by Graphical Illustration

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IEEE Transactions on Power systems 2025年第2期40卷 1973-1976页

作者： Yang, Jialun Ye, Hua Wang, Yantuan Liu, Yutian Li, Yujun Du, Zhengchun Shandong Research Institute of Industrial Technology Jinan250061 China Shandong University Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education Jinan250061 China Xi'an Jiaotong University Department of Electrical Engineering Xi'an710049 China

The existing priority-based current limiting control (CLC) for grid-forming (GFM) inverters may lead to failures in fault recovery, including being locked in CLC and mode oscillation between CLC and constant voltage control (CVC). To resolve these problems, this letter first reveals the fault recovery mechanism of droop controlled GFM inverters by illustrating the conditions of three fault recovery states in the phasor diagram. Then, two methods including determination of the optimal range of current angle and upper limit of saturation block are presented to guarantee successful fault recovery of GFM inverters. The correctness of theoretical analyses is verified and validated by multiple experimental tests. © 1969-2012 IEEE.

关键词： Fault current limiters

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