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抑制载荷的大型风电机组滑模变桨距控制

电工技术学报 2013年第7期28卷 145-150页

作者：肖帅杨耕耿华清华大学自动化系北京100084

随着现代风电机组的不断大型化,风机机械零部件(塔架、桨叶和传动轴等)的柔性不断增大,从而产生较大的疲劳载荷。从控制方法上减少这些载荷将会有效地延长风电机组的使用寿命。对于高风速工作区,传统的桨距角控制采用比例积分线性调节器... 详细信息

随着现代风电机组的不断大型化,风机机械零部件(塔架、桨叶和传动轴等)的柔性不断增大,从而产生较大的疲劳载荷。从控制方法上减少这些载荷将会有效地延长风电机组的使用寿命。对于高风速工作区,传统的桨距角控制采用比例积分线性调节器,且控制目标仅考虑风机转速,该方法并未考虑风机的载荷信息,因而无法有效抑制其载荷。本文基于滑模控制理论,在传统控制目标的基础上,提出了一种降低风电机组载荷的多目标变桨距控制策略,在控制风电机组转速恒定的同时,可有效抑制风机塔架和桨叶的机械振动。采用FAST仿真软件,通过与传统桨距角控制方法相比,验证了所提出控制策略的有效性。此外,所设计的滑模控制策略原理简单、易于实现,且对系统参数变化也具有较好的鲁棒性。

关键词：大型风电机组变桨距控制载荷抑制滑模控制

配置STATCOM的DFIG风电场在不对称电网故障下的控制策略

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中国电机工程学报 2013年第19期33卷 27-38,22页

作者：郑重杨耕耿华清华大学自动化系北京市海淀区100084

该文研究在不对称电网故障穿越的第2阶段,双馈式(doubly-fed induction generator,DFIG)风电场如何实现"自身不脱网安全运行并同时满足并网导则无功支撑要求"的问题。由于受限于变流器的容量,DFIG机组无法保证在所有故障情况下实现既定... 详细信息

该文研究在不对称电网故障穿越的第2阶段,双馈式(doubly-fed induction generator,DFIG)风电场如何实现"自身不脱网安全运行并同时满足并网导则无功支撑要求"的问题。由于受限于变流器的容量,DFIG机组无法保证在所有故障情况下实现既定的控制目标。为此,通过引入最优化的方法,分析了变流器容量限制条件下DFIG机组的可控性问题,得到了以电网电压不平衡度所量化表示的可控区,指出为确保在不对称跌落故障较严重时能满足并网导则要求,有必要在DFIG风电场层面配置静止同步补偿器(staticsynchronous compensator,STATCOM)以降低场内DFIG机组的机端电压不平衡度。最后,设计了STATCOM所需容量最小的电压补偿控制策略,并给出了相应的容量匹配方法。仿真结果验证了该文提出的在不对称低电压穿越(lowvoltage ride-through,LVRT)第2阶段DFIG机组可控区的正确性、STATCOM辅助控制策略的有效性以及相应容量匹配方法的可行性。

关键词：风力发电双馈感应发电机不对称电网故障低电压穿越静止同步补偿器容量匹配

Tirapazamine encapsulated hyaluronic acid nanomicelles realized targeted and efficient photo-bioreductive cascading cancer therapy

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Chinese Chemical Letters 2021年第8期32卷 2400-2404页

作者： Chunhui Wu Qiuyue Liu Yikun Wang Zhengxin Xie Honglin Huang Ningxi Li Xiaodan Wei geng yang Tingting Li Hong yang Shun Li Xiang Qin Yiyao Liu Department of Biophysics School of Life Science and TechnologyUniversity of Electronic Science and Technology of ChinaChengdu 610054China TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province Hospital of Chengdu University of Traditional Chinese MedicineChengdu 610072China

Currently,architecting a ratio nal and efficient nanoplatform combing with multi-therapeutic modalities is highly obligatory for advanced cancer *** order to remedy the self-limiting hypoxic dilemma of photodynamic therapy(PDT),herein,a facile photosensitizer(i.e.,chlorin e6,Ce6) and bioreductive prodrug(i.e.,tirapazamine,TPZ)-coloaded hyaluronic acid(HA) nanomicelles(denoted as TPZ@HA-Ce6)was developed for the cascading mode of photo-bioreductive cancer *** the typical advantage of Ce6 coupled HA conjugate,TPZ was easily and successfully accommodated into the hydrophobic core of HA-Ce6 nanomicelles,yielding TPZ@*** showed good dispersibility and stability with the hydrodynamic size of ca.170 *** targeted the CD44 overexpressed cancer cells by receptor-mediated endocytosis way and killed them effectively with singlet oxygen and the subsequent TPZ radicals resulting from the oxygen depletion of *** later was further verified by the hypoxia probe in *** murine mammary carcinoma 4 T1 model,TPZ@HA-Ce6 nanomicelles exhibited cascading and synergistic anticancer effect of PDT and TPZ bioreductive therapy compared with each *** work suggests the promising prospect of the hybrid hyaluronic nanomicelles for highly efficient cancer combination treatment.

关键词： Hyaluronic acid Photosensitizer Bioreductive prodrug Hypoxia Cascading cancer therapy

Remarkable Wear Resistance in a Complex Concentrated Alloy with Nanohierarchical Architecture and Composition Undulation

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Research 2024年第1期2023卷 403-416页

作者： Yushan geng Wenyuan Chen Hui Tan Jun Cheng Shengyu Zhu Jun yang Weimin Liu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000PR China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049PR China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264000PR China

Sustained wear damages on the sliding surfaces of alloys are generally the culprit responsible for the failure of various mechanical *** by high-entropy effects,here we deliberately deploy nanohierarchical architecture with composition undulation in a Ni50(AlNbTiV)_(50) complex concentrated alloy,which yields ultralow wear rate within the order of 10^(−7) to 10^(−6) mm^(3)/Nm between room temperature and 800℃.Such remarkable wear resistance heretofore represents one of the highest wear resistance reported for the bulk alloys or composites,and originates from the multi-type adaptive friction interface protection governed by intrinsically nano-coupled grains and *** cooperative heterostructure releases gradient frictional stress in stages upon wear at room temperature through the coexistence of multiple deformation pathways while activating a dense nanocrystalline glaze layer upon wear at 800℃ to minimize adhesive and oxidative *** work uncovers a practical avenue for tailoring wear properties with multicomponent heterostructures over a wide temperature range.

关键词： wear alloys friction

Standardized Volume Power Density Boost in Frequency-Up Converted Contact-Separation Mode Triboelectric Nanogenerators

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Research 2024年第2期2023卷 691-702页

作者： Zhongjie Li Chao yang Qin Zhang geng Chen Jingyuan Xu Yan Peng Hengyu Guo School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444P.R.China Institute of Artificial Intelligence Shanghai UniversityShanghai 200444P.R.China National Engineering Research Center of Turbo-Generator Vibration School of Energy and EnvironmentSoutheast UniversityNanjing 210096P.R.China institute of Microstructure Technology Karlsruhe Institute of TechnologyKarlsruhe 76344Germany Shanghai Artificial Intelligence Laboratory Shanghai 200444P.R.China Department of Applied Physics Chongqing UniversityChongqing 400044P.R.China

The influence of a mechanical structure's volume increment on the volume power density (VPD) of triboelectric nanogenerators (TENGs) is often neglected when considering surface charge density and surface power density. This paper aims to address this gap by introducing a standardized VPD metric for a more comprehensive evaluation of TENG performance. The study specifically focuses on 2 frequency-up mechanisms, namely, the integration of planetary gears (PG-TENG) and the implementation of a double-cantilever structure (DC-TENG), to investigate their impact on VPD. The study reveals that the PG-TENG achieves the highest volume average power density, measuring at 0.92 W/m^(3). This value surpasses the DC-TENG by 1.26 times and the counterpart TENG by a magnitude of 69.9 times. Additionally, the PG-TENG demonstrates superior average power output. These findings introduce a new approach for enhancing TENGs by incorporating frequency-up mechanisms, and highlight the importance of VPD as a key performance metric for evaluating TENGs.

关键词： increment neglected considering

Intelligent overheating fault diagnosis for overhead transmission line using semantic segmentation

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High Voltage 2024年第2期9卷 309-318页

作者： Xiangyu yang Youping Tu Zhikang Yuan Zhong Zheng geng Chen Cong Wang Yan Xu Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijingChina College of Electronic and Information Engineering Tongji UniversityShanghaiChina

The strain clamps and leading wires are important components that connect conductors on overhead transmission lines and conduct *** operation,poor contact between these components can cause abnormal overheating,leading to electric failures and threatening power system ***,the use of unmanned aerial vehicles equipped with infrared thermal imagers for strain clamp and leading wire maintenance has become increasingly *** learning-based image recognition shows promising prospects for intelligent fault diagnosis of overheating faults.A pre-treatment method is proposed based on dynamic histogram equalisation to enhance the contrast of infrared *** DeepLab v3+network,loss function,and existing networks with different backbones are *** DeepLab v3+network with ResNet101 and convolutional block attention module added,and the Focal Loss function achieved the highest performance with an average pixel accuracy of 0.614,an average intersection over union(AIoU)of 0.567,an F1 score of 0.644,and a frequency weighted intersection over union of 0.594 on the test *** optimised Atrous rates has increased the AIoU by 12.91%.Moreover,an intelligent diagnosis scheme for evaluating the defect state of the strain clamps and leading wires is proposed and which achieves a diagnostic accuracy of 91.0%.

关键词： union fault diagnosis

大型风电机组的比例-积分-谐振独立变桨距控制策略

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电力自动化设备 2017年第1期37卷 87-92页

作者：杨文韬耿华肖帅杨耕清华大学自动化系北京100084 北京控制工程研究所北京100190

提出一种用于降低风轮不平衡载荷的比例-积分-谐振独立变桨距控制策略,该控制器由比例-积分控制器和谐振控制器两部分组成,其中比例-积分控制器用于抑制不平衡载荷的1p(风轮旋转频率的倍数)分量,谐振控制器则用于抑制不平衡载荷的高频分... 详细信息

提出一种用于降低风轮不平衡载荷的比例-积分-谐振独立变桨距控制策略,该控制器由比例-积分控制器和谐振控制器两部分组成,其中比例-积分控制器用于抑制不平衡载荷的1p(风轮旋转频率的倍数)分量,谐振控制器则用于抑制不平衡载荷的高频分量(2p、4p)。采用FAST软件对所提出的控制策略进行了仿真验证,仿真结果表明所提出的控制策略可以在传统比例-积分控制的基础上,进一步降低风轮所承受的高频不平衡载荷。

关键词：风电机组独立变桨控制不平衡载荷疲劳载荷比例-积分-谐振控制

最大功率跟踪控制下大型风电机组的轴系扭振分析及抑制

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清华大学学报（自然科学版） 2015年第11期55卷 1171-1177页

作者：杨文韬耿华肖帅杨耕清华大学自动化系北京100084 北京控制工程研究所北京100190

随着风电机组向大型化和轻量化发展,机组传动轴扭振现象加剧,风机轴系扭振的研究变得越来越重要。该文分析了3种常用的风机最大功率跟踪控制方法下系统轴系扭振模态,发现利用发电机转速反馈的不同控制方法,都能够提升传动轴阻尼。据此... 详细信息

随着风电机组向大型化和轻量化发展,机组传动轴扭振现象加剧,风机轴系扭振的研究变得越来越重要。该文分析了3种常用的风机最大功率跟踪控制方法下系统轴系扭振模态,发现利用发电机转速反馈的不同控制方法,都能够提升传动轴阻尼。据此提出了一种最大功率跟踪控制的改进方法,该方法在原有转矩指令的基础上叠加了传动轴扭振抑制指令,在保证最大功率跟踪的同时抑制了风机传动轴扭振。通过软件仿真,验证了上述理论分析以及改进方法的有效性。

关键词：大型风电机组最大功率跟踪传动轴扭振

Senescent bone marrow microenvironment promotes Nras-mutant leukemia

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Journal of Molecular Cell Biology 2021年第1期13卷 72-74页

作者： Peiqing Zhou Chengxiang Xia Tongjie Wang Yong Dong Qitong Weng Xiaofei Liu yang geng Jinyong Wang Juan Du CAS Key Laboratory of Regenerative Biology Guangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhou 510530China University of Chinese Academy of Sciences Beijing 100049China Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine Guangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhou 510530China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory) Guangzhou 510005China

Dear Editor,In recent years,there is growing interest regarding the roles of senescent bone marrow(BM)microenvironment in the initiation of *** mice transplanted with AML1-ETO(AML1-ETO fusion protein)-positive hematopoietic stem cells(HSCs)present with a significant increase in the frequency of AMLETO-positive early progenitor cells in BM as well as an in crease of immature myeloid cells compared to young recipients(Vas et aL,2012).BM mesenchymal stem cells(MSCs)from myelodysplastic syndromes(MDS)animal models and MDS patients exhibit impaired proliferation and differentiation potentials,abnormal cytoki ne secretion,and dysregulated gene expression profile(Lopez-Villar et al.,2009;Geyh et al.,2013;Mattiucci et al.,2018).However,the causal relationship between senes・cent BM microenvironment and leukemia development is *** senes・cent BM microenvironment initiates or accelerates leukemia development remains unknown.

关键词： al. microenvironment impaired