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Studies on the active SISFCL and its impact on the distance protection of the EHV transmission line

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Protection and Control of Modern Power Systems 2016年第1期1卷 164-169页

作者： Chao Li Bin Li Fengrui Guo jianzhao geng Xiuchang Zhang Tim Coombs EPEC Superconductivity Group University of CambridgeCambridge CB30FAUK Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China State Grid Tianjin Electric Power Company Tianjin 300010China.

The active saturated iron-core superconductive fault current limiter(SISFCL)is a good choice to decrease fault *** paper introduced the principles and impedance characteristic of the active ***,it shows the current-limiting effects of the ***,the impact of the active SISFCL on the distance protection of the EHV transmission line is *** on that,the coordination scheme of the distance protections is proposed.A 500 kV double-circuit transmission system with SISFCLs is simulated by Electro-Magnetic Transients Program including DC(EMTDC).Simulation tests demonstrate the correctness and validity of theoretical analyses.

关键词： Superconductive Fault current limiter(SFCL) Saturated iron core Distance protection Current-limiting effects

基于介质击穿原理的配电线路高阻接地故障精确建模

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电力系统自动化 2014年第12期38卷 62-66,106页

作者：王宾耿建昭董新洲清华大学电机工程与应用电子技术系北京市100084 电力系统及发电设备控制和仿真国家重点实验室清华大学北京市100084

配电线路负荷率快速增加和电缆线路的广泛应用使得配电网中性点有效接地方式得到越来越多的应用。中性点有效接地配电线路受送电走廊、自然环境等因素影响,容易发生弧光高阻接地故障;此类故障电流幅值小,保护难以检测跳闸,很少能获取到... 详细信息

配电线路负荷率快速增加和电缆线路的广泛应用使得配电网中性点有效接地方式得到越来越多的应用。中性点有效接地配电线路受送电走廊、自然环境等因素影响,容易发生弧光高阻接地故障;此类故障电流幅值小,保护难以检测跳闸,很少能获取到现场录波数据;而人工接地试验成本高,难以频繁使用,因此挖掘有限的试验数据,实现弧光高阻接地模型的精确建模尤为重要。文中在详细分析基于热平衡原理的电弧模型机理的基础上,指出了该类模型不完全适用于开放空间,以及弱故障电流的高阻弧光接地故障。针对以上问题,文中基于固体介质电击穿原理,提出并建立了配电线路高阻接地故障点非线性电阻模型,理论分析及现场试验数据验证了模型的准确性;为后续的高阻接地故障检测算法研究奠定了理论基础。

关键词：中性点有效接地配电系统高阻接地间歇性电弧伏安特性介质击穿

利用单相跳闸后信息的输电线路单相接地单端精确测距方法

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电工技术学报 2015年第16期30卷 184-193页

作者：耿建昭王宾董新洲清华大学电机系电力系统及发电设备安全控制和仿真国家重点试验室北京100084

输电线路单端阻抗测距方法受过渡电阻和对端系统阻抗的影响,测距精度较低。输电线路单相接地故障普遍采用单相跳闸的运行方式,非全相运行过程仍包含对端系统信息,使单端精确测距成为可能。现存的利用单相跳闸后信息的测距方法利用简单的... 详细信息

输电线路单端阻抗测距方法受过渡电阻和对端系统阻抗的影响,测距精度较低。输电线路单相接地故障普遍采用单相跳闸的运行方式,非全相运行过程仍包含对端系统信息,使单端精确测距成为可能。现存的利用单相跳闸后信息的测距方法利用简单的R-L线路模型,未考虑线路分布电容、相间耦合、潜供电流等因素影响,针对该问题,本文基于分布参数模型,利用故障后以及单相跳闸后两个时间断面的信息描述输电线路方程,能精确计算出包括对端系统电动势、对端系统阻抗、故障距离和过渡电阻在内的所有网络未知参数。本文理论分析和仿真结果表明:所提出的算法具有较高的测距精度,能够满足现场应用的要求。

关键词：输电线路单端故障测距单相跳闸分布参数

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配网高阻接地故障伏安特性分析及检测

中国电机工程学报 2014年第22期34卷 3815-3823页

作者：王宾耿建昭董新洲电力系统及发电设备控制和仿真国家重点实验室(清华大学电机工程与应用电子技术系) 北京市海淀区100084

中性点有效接地中压配电网常发生弧光高阻接地故障,短路电流小,零序保护无法动作切除,但存在的电弧易引发火灾、人身伤亡等恶性事故。传统故障检测算法一般基于电弧热平衡模型,采用基于傅里叶变换的频域信号分析方法,但在非线性电弧的... 详细信息

中性点有效接地中压配电网常发生弧光高阻接地故障,短路电流小,零序保护无法动作切除,但存在的电弧易引发火灾、人身伤亡等恶性事故。传统故障检测算法一般基于电弧热平衡模型,采用基于傅里叶变换的频域信号分析方法,但在非线性电弧的强噪声环境下检测成功率较低。针对该问题,首先提出了基于固体介质电击穿原理的非线性电弧模型,分析了电路线性元件和高阻接地非线性电阻的伏安特性,从时域角度采用最小二乘线性拟合抽取故障特征,提出了基于故障电阻非线性识别的高阻接地故障检测算法。大量仿真数据和现场试验数据证明了该故障模型比传统模型更精确,且所提检测算法具有较高的灵敏性和可靠性。

关键词：配电系统高阻接地故障伏安特性最小二乘拟合非线性识别

中性点有效接地配电网高阻接地故障特征分析及检测

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电力系统自动化 2013年第16期37卷 85-91页

作者：耿建昭王宾董新洲 Bak DOMINIK 清华大学电机工程与应用电子技术系北京市100084 电力系统及发电设备控制和仿真国家重点实验室清华大学北京市100084 浙江清华长三角研究院浙江省嘉兴市314006

中性点经小电阻等有效接地方式能有效地克服配电系统单相接地故障暂态过电压超标及故障选线不灵敏等问题,逐渐在城市配电网、大型厂矿企业电网中得到了推广应用;但这种运行方式仍然存在弧光接地等高阻接地故障正确动作率较低的问题。针... 详细信息

中性点经小电阻等有效接地方式能有效地克服配电系统单相接地故障暂态过电压超标及故障选线不灵敏等问题,逐渐在城市配电网、大型厂矿企业电网中得到了推广应用;但这种运行方式仍然存在弧光接地等高阻接地故障正确动作率较低的问题。针对该问题,文中分析了高阻接地故障的特征,给出并验证了适用于配电网高阻故障检测的故障点电弧模型。针对现有方法中主要利用频域特征来检测高阻接地故障导致成功率低的缺点,提出了一种基于零序电流波形畸变凹凸性的高阻接地故障检测方法,仿真实验与现场试验数据验证了该算法的灵敏性和可靠性。

关键词：配电系统高阻接地故障弧光接地凹凸性

Quantum purification for coherent states and its application

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 37-50页

作者： Lei Wang geng Chai Zhengwen Cao Xinlei Chen Kexin Liang Jinye Peng Laboratory of Quantum Information and Technology School of Information Science and TechnologyNorthwest UniversityXi'an 710127China

The inevitable decoherence of quantum states leaks information to the environments and reduces the practical performance of quantum-information *** purification of coherent states provides an easy-to-implement approach to decouple from the environments utilizing the correlation of several ***,repeated transmission of quantum states reduces the randomness of the collectivity and generates security *** this paper,we propose a modified purification scheme and apply it to the continuous-variable quantum secure direct communication(CV-QSDC)protocol based on coherent *** designed purification scheme improves the security capacity of communication systems through the effective suppression of excess noises,accompanied by the maintenance of source-side *** conduct a proof-of-principle experiment of the purification scheme in the CV-QSDC *** appearance of transmitted quantum states in phase space and two-dimensional Gaussian distributions have high goodness of fit at two *** security capability of this system is improved by 43.6%as the excess noise is reduced to 0.58 times the original noise by purification.

关键词： quantum purification coherent state quantum secure direct communication

Explaining the better generalization of label distribution learning for classification

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Science China(Information Sciences) 2025年

作者： Jing WANG Xin geng School of Computer Science and Engineering Southeast University Key Laboratory of New Generation Artificial Intelligence Technology and Its Interdisciplinary Applications(Southeast University) Ministry of Education

Label distribution learning (LDL) has shown advantages over traditional single-label learning (SLL) in many realworld applications, but its superiority has not been theoretically understood. In this paper, we attempt to explain why LDL generalizes better than SLL. Label distribution has rich supervision information such that an LDL method can still choose the sub-optimal label from label distribution even if it neglects the optimal one. In comparison, an SLL method has no information to choose from when it fails to predict the optimal label. The better generalization of LDL can be credited to the rich information of label distribution. We further establish the label distribution margin theory to prove this explanation; inspired by the theory,we put forward a novel LDL approach called LDL-LDML. In the experiments, the LDL baselines outperform the SLL ones, and LDL-LDML achieves competitive performance against existing LDL methods, which support our explanation and theories in this paper.

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Edge-aware Feature Aggregation Network for Polyp Segmentation

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Machine Intelligence Research 2025年第1期22卷 101-116页

作者： Tao Zhou Yizhe Zhang geng Chen Yi Zhou Ye Wu Deng-Ping Fan PCA Lab Key Laboratory of Intelligent Perception and Systems for High-dimensional Information of Ministry of EducationSchool of Computer Science and EngineeringNanjing University of Science and TechnologyNanjing210094China School of Computer Science and Engineering Northwestern Polytechnical University(NPU)Xi’an710129China School of Computer Science and Engineering Southeast UniversityNanjing211189China Computer Vision Lab ETH ZürichZürich8092Switzerland

Precise polyp segmentation is vital for the early diagnosis and prevention of colorectal cancer(CRC)in clinical ***,due to scale variation and blurry polyp boundaries,it is still a challenging task to achieve satisfactory segmentation performance with different scales and *** this study,we present a novel edge-aware feature aggregation network(EFA-Net)for polyp segmentation,which can fully make use of cross-level and multi-scale features to enhance the performance of polyp ***,we first present an edge-aware guidance module(EGM)to combine the low-level features with the high-level features to learn an edge-enhanced feature,which is incorporated into each decoder unit using a layer-by-layer ***,a scale-aware convolution module(SCM)is proposed to learn scale-aware features by using dilated convolutions with different ratios,in order to effectively deal with scale ***,a cross-level fusion module(CFM)is proposed to effectively integrate the cross-level features,which can exploit the local and global contextual ***,the outputs of CFMs are adaptively weighted by using the learned edge-aware feature,which are then used to produce multiple side-out segmentation *** results on five widely adopted colonoscopy datasets show that our EFA-Net outperforms state-of-the-art polyp segmentation methods in terms of generalization and *** implementation code and segmentation maps will be publicly at https://***/taozh2017/EFANet.

关键词： Colorectal cancer polyp segmentation edge-aware guidance module scale-aware convolution module cross-level fusion module

Impact of aerosol-radiation interaction and heterogeneous chemistry on the winter decreasing PM_(2.5)and increasing O_(3)in Eastern China 2014–2020

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Journal of Environmental Sciences 2025年第5期151卷 469-483页

作者： Yasong Li Tijian Wang Qin’geng Wang Mengmeng Li Yawei Qu Hao Wu Min Xie School of the Environment Nanjing UniversityNanjing 210023China School of Atmospheric Sciences Nanjing UniversityNanjing 210023China College of Intelligent Science and Control Engineering Jinling Institute of TechnologyNanjing 211169China Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041China School of Environment Nanjing Normal UniversityNanjing 210023China

In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern *** analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)*** reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis *** reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)*** and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,*** response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)*** ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)*** investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.

关键词： Aerosol-radiation interaction Heterogeneous chemistry O_(3)increase PM_(2.5)decrease Emission reduction