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基于ICEEMDAN和时变权重集成预测模型的变压器油中溶解气体含量预测

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高电压技术 2024年第1期50卷 210-220页

作者：马宏忠肖雨松孙永腾李勇朱雷许洪华河海大学能源与电气学院南京211100 国网江苏省电力有限公司南京供电分公司南京210008

为了实现对变压器油中溶解气体体积分数的精确预测,同时克服仅使用单一预测模型导致预测精度及泛化能力不足的局限,提出了一种基于改进完全自适应噪声集合经验模态分解(improved complete ensemble empirical mode decomposition,ICEEMD... 详细信息

为了实现对变压器油中溶解气体体积分数的精确预测,同时克服仅使用单一预测模型导致预测精度及泛化能力不足的局限,提出了一种基于改进完全自适应噪声集合经验模态分解(improved complete ensemble empirical mode decomposition,ICEEMDAN)和灰色关联系数时变权重集成预测模型的变压器油中溶解气体预测方法。首先将溶解气体含量序列模态分解为一系列具有不同时间尺度的子序列。然后,使用门控循环神经网络和麻雀搜索算法优化支持向量机对各子序列进行训练,组合为一个集成预测模型;并比较不同预测方法的预测精度,计算灰色关联系数时变权重,形成各子系列的预测结果。最后将各子序列的预测结果叠加重构,得到最终预测结果。算例分析结果显示:该方法单步预测的均方根误差、平均绝对误差和相关系数分别为0.593、0.422和0.768,相比其他算法在预测精度上有明显提升,同时具有很强的泛化性能,可以为油浸式变压器内部状态监测提供依据。

关键词：油中溶解气体 ICEEMDAN 麻雀搜索算法支持向量机门控循环神经网络时变权重集成模型

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可再生能源综合系统现状与未来发展趋势研究

太阳能 2024年第7期 127-132页

作者：邵桂萍许洪华中国科学院电工研究所北京100190

通过分析中国能源结构现状与能源转型面临的主要挑战,结合未来能源需求,研究适合中国国情的低碳、低成本的能源转型现实路径,提出以可再生能源为主体、多能源互补、“冷热电”联供、集“源网荷”于一体的新型能源系统解决方案——可再... 详细信息

通过分析中国能源结构现状与能源转型面临的主要挑战,结合未来能源需求,研究适合中国国情的低碳、低成本的能源转型现实路径,提出以可再生能源为主体、多能源互补、“冷热电”联供、集“源网荷”于一体的新型能源系统解决方案——可再生能源综合系统;然后对可再生能源综合系统的现状与关键技术进行了研究,并分析了其未来发展趋势。研究结果表明:围绕用户侧构建分层次、分场景的以可再生能源为主体的集“冷热电”“源网荷”于一体的新型能源系统,是中国实现能源转型的系统解决方案。

关键词：可再生能源综合系统碳中和新型能源系统能源转型能源结构多能互补

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基于近邻成分分析与优化核极限学习机的光伏接入配电网漏电识别

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高压电器 2024年第6期60卷 203-211页

作者：汪自虎王文天惠慧王铭李刚许洪华国网江苏省电力有限公司南京供电分公司南京210019 中国电力科学研究院有限公司北京100192

在光伏接入的配电网中,现有漏电保护装置无法区分光伏设备漏电流与发生生物触电时的故障漏电流,导致系统存在安全隐患。针对此问题,提出一种基于近邻成分分析(neighborhood component analysis,NCA)与核极限学习机(kernel extreme learn... 详细信息

在光伏接入的配电网中,现有漏电保护装置无法区分光伏设备漏电流与发生生物触电时的故障漏电流,导致系统存在安全隐患。针对此问题,提出一种基于近邻成分分析(neighborhood component analysis,NCA)与核极限学习机(kernel extreme learning machine,KELM)的光伏接入配电网漏电识别方法。首先,构建了9维原始故障特征集,并采用NCA从9维特征集中选择得到4维高相关性特征子集;然后,将得到的4维特征子集作为KELM的输入,建立基于KELM的漏电识别模型,并通过麻雀搜索算法(sparrow search algorithm,SSA)对KELM模型中的参数进行优化;最后,将所提SSA-KELM方法应用于漏电识别,并与标准核极限学习机(KELM)、支持向量机(SVM)、BP神经网络(BPNN)进行了对比。比较结果表明:SSA-KELM对光伏接入配电网漏电类型的识别率最高,平均识别准确率达97.98%,为有效识别生物体触电与光伏漏电提供一定理论参考。

关键词：光伏接入的配电网生物触电光伏设备漏电近邻成分分析核极限学习机麻雀搜索算法

Robust current control design of a three phase voltage source converter

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Journal of Modern Power Systems and Clean Energy 2014年第1期2卷 16-22页

作者： Wenming GONG Shuju HU Martin SHAN honghua xu University of Chinese Academy of Sciences Beijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China Control Engineering and Energy Storage Systems Fraunhofer IWES34119 KasselGermany

In this paper,a robust design method for current control is proposed to improve the performance of a three phase voltage source converter(VSC)with an inductorcapacitor-inductor(LCL)*** presence of the LCL filter complicates the dynamics of the control system and limits the achievable control bandwidth(and the overall performance),particularly when the uncertainty of the parameters is *** solve this problem,the advanced H?control theory is employed to design a robust current controller in stationary *** control of the fundamental frequency current and suppression of the potential LC resonance are *** design procedure and the selection of the weight functions are presented in detail.A conventional proportional-resonant PR controller is also designed for *** showed that the proposed H∞ current controller achieved a good frequency response with explicit *** conclusion was verified on a 5 kW VSC that had a LCL filter.

关键词： Current control H∞control Robust control Inductor-capacitor-inductor(LCL)filter Voltage source converter(VSC)

Single-phase-to-ground Fault Detection with Distributed Parameters Analysis in Non-direct Grounded Systems

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CSEE Journal of Power and Energy Systems 2019年第1期5卷 139-147页

作者： Baowen Liu Hongzhong Ma honghua xu Ping Ju College of Energy and Electrical Engineering Hohai UniversityNanjing 211100China State Grid Jiangsu Electric Power Company Nanjing Power Supply Company Nanjing 210008China

The fast and accurate detection of the single-phaseto-ground fault is of great significance for the reliability and safety of the power *** this paper,novel algorithms for distribution network protection were proposed with distributed parameters analysis in non-direct grounded *** first,novel generating mechanisms of zero-sequence voltage and residual current were *** the compositions of residue parameters,including residual current and residual admittances,were decomposed in *** that,an improved algorithm for a fault resistance calculation of a single phase-to-earth fault was also proposed,and the algorithm is much more convenient as it only needs to measure the variation of the zero-sequence voltage and does not need the prerequisites of the faulty feeder ***,the fault feeder can also be selected by an improved calculation algorithm of zero-sequence admittance of the faulty feeder,which cannot be affected by the asymmetry of the *** analysis and the MATALB/Simulink simulation results demonstrate the effectiveness of the proposed algorithms.

关键词： Fault resistance calculation fault feeder selection non-direct grounded system residual parameters residual current zero-sequence voltage

High-performance grinding of ceramic matrix composites

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Nanotechnology and Precision Engineering 2024年第3期7卷 45-55页

作者： Jingfei Yin Jiuhua xu honghua Su College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Technology Center AECC Shenyang Liming Aero-engine Co.Ltd.Shenyang 110043China

Ceramic matrix composites(CMCs)are highly promising materials for the next generation of ***,machining of CMCs suffers from low efﬁciency and poor surfaceﬁnish,which presents an obstacle to their wider *** overcome these problems,this study investigates high-efﬁciency deep grinding of CMCs,focusing on the effects of grinding *** results show that both the sur-face roughness and the depth of subsurface damage(SSD)are insensitive to grinding *** material removal rate can be increased sixfold by increasing the grinding depth,while the surface roughness and SSD depth increase by only about 10%.Moreover,it is found that the behavior of material removal is strongly dependent on grinding *** the grinding depth is increased,ﬁbers are removed in smaller sizes,with theﬁber length in chips being reduced by about 34%.However,too large a grinding depth will result in blockage by chip powder,which leads to a dramatic increase in the ratio of tangential to normal grinding *** study demonstrates that increasing the depth of cut is an effective approach to improve the machining efﬁciency of CMCs,while maintaining a good surfaceﬁ*** provides the basis for the further development of high-performance grinding methods for CMCs,which should facilitate their wider application.

关键词： Ceramic matrix composite Grinding Surfaceﬁnish Subsurface damage Fiber breakage

一种多模块图注意力机制和词库构建的电力敏感数据识别算法

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电力信息与通信技术 2024年第7期22卷 27-34页

作者：朱红勤余璟王黎明许洪华马楠国网江苏省电力有限公司南京供电分公司江苏省南京市210019

在大数据时代下,电力行业的数据共享和融合存在巨大的风险。为此,文章提出了一种基于多模块图注意力机制的新文本分类算法。首先将图注意力机制与Transformer相结合,引入句法关系并运用图注意力机制提取文本特征;其次,为了提高敏感词识... 详细信息

在大数据时代下,电力行业的数据共享和融合存在巨大的风险。为此,文章提出了一种基于多模块图注意力机制的新文本分类算法。首先将图注意力机制与Transformer相结合,引入句法关系并运用图注意力机制提取文本特征;其次,为了提高敏感词识别准确性以及改善分词工具对敏感词的识别,提出了一种新型敏感词库构建方法。实验证明,文章提出的方法在敏感文本分类任务中表现出色,同时具备良好的可扩展性。

关键词：敏感数据词库构建和扩展智能识别和分类

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Research and practice of designing hydro/ photovoltaic hybrid power system in microgrid

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Engineering Sciences 2013年第3期11卷 80-84,96页

作者： Wang Yibo xu honghua Solar Thermal Technology and Photovoltaic System Laboratory Chinese Academy of Science

Small-hydro power station is often used in remote areas beside a river,but it doesn't match electricity demand so well,especially in dry seasons. A photovoltaic (PV) system with battery is a suitable option to complement the electricity gap. In this paper,a new structure of megawatt-class PV system integrating battery at DC-bus (DC: direct current) is proposed to be used in hydro/PV hybrid power system,and 4 main designing considerations and several key equipments are discussed. In 2011,a 2 MWp PV station with the proposed structure was built up in Yushu,China. From stability analysis,the station shows a strong stability under load cut-in/off and solar irradiance's fluctuation.

关键词： photovoltaic system with battery hydro/PV hybrid power system isolated microgrid

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不同挤压参数对大豆粕蛋白质结构的影响

农业工程学报 2007年第7期23卷 267-271页

作者：徐红华申德超东北农业大学食品学院

该文系统研究了油脂提取前挤压膨化预处理工艺对大豆粕蛋白质表面疏水性、游离巯基含量的影响,分析了物料水分、膨化温度、δ段长度、模孔长度、螺杆转速等不同挤压参数与蛋白质结构变化的关系,建立了挤压参数与粕蛋白质游离巯基含量关... 详细信息

该文系统研究了油脂提取前挤压膨化预处理工艺对大豆粕蛋白质表面疏水性、游离巯基含量的影响,分析了物料水分、膨化温度、δ段长度、模孔长度、螺杆转速等不同挤压参数与蛋白质结构变化的关系,建立了挤压参数与粕蛋白质游离巯基含量关系的量化模型。结果表明:低物料水分、低膨化温度、短模孔可以减少挤压膨化预处理工艺过程中蛋白质结构的破坏程度。相反,高物料水分、高温挤压膨化时,会加剧蛋白质分子内部疏水基的暴露和蛋白质的交联。在此基础上改进的挤压膨化预处理工艺更有利于蛋白质结构的改善。

关键词：挤压膨化大豆粕蛋白表面疏水性溶解性