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A Loss-model-based Efficiency Optimization Control Method for Induction Traction System of High-speed Train under Emergency Self-propelled Mode

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 227-239页

作者： Yutong Zhu yaohua li Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100190China China Academy of Railway Sciences Corporation limited(Beijing Zongheng Electromechanical Technology Co.Ltd Beijing 100081 China IEEE

Increasing attention has been paid to the efficiency improvement of the induction traction system of high-speed trains due to the high demand for energy saving. In emergency self-propelled mode, however, the dc-link voltage and the traction power of the motor are significantly reduced, resulting in decreased traction efficiency due to the low load and low speed operations. Aiming to tackle this problem, a novel efficiency improved control method is introduced to the emergency mode of high-speed train traction system in this paper. In the proposed method, a total loss model of induction motor considering the behaviors of both iron and copper loss is established. An improved iterative algorithm with decreased computational burden is then introduced, resulting in a fast solving of the optimal flux reference for loss minimization at each control period. In addition, considering the parameter variation problem due to the low load and low speed operations, a parameter estimation method is integrated to improve the controller's robustness. The effectiveness of the proposed method on efficiency improvement at low voltage and low load conditions is demonstrated by simulated and experimental results.

关键词： Efficiency optimization Induction motor Loss model control Motor drives Traction system

Coordinated Capacitor Voltage Balancing Method for Cascaded H-bridge Inverter with Supercapacitor and DC-DC Stage

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 191-201页

作者： Ye Zhang Zixin li Fanqiang Gao Cong Zhao yaohua li IEEE Key Laboratory of High Density Electromagnetic Power and Systems(Chinese Academy of Sciences) Institute of Electrical EngineeringChinese Academy of SciencesHaidian District University of Chinese Academy of Sciences Shijingshan District

Cascaded H-bridge inverter(CHBI) with supercapacitors(SCs) and dc-dc stage shows significant promise for medium to high voltage energy storage applications. This paper investigates the voltage balance of capacitors within the CHBI, including both the dc-link capacitors and SCs. Balance control over the dc-link capacitor voltages is realized by the dcdc stage in each submodule(SM), while a hybrid modulation strategy(HMS) is implemented in the H-bridge to balance the SC voltages among the SMs. Meanwhile, the dc-link voltage fluctuations are analyzed under the HMS. A virtual voltage variable is introduced to coordinate the balancing of dc-link capacitor voltages and SC voltages. Compared to the balancing method that solely considers the SC voltages, the presented method reduces the dc-link voltage fluctuations without affecting the voltage balance of SCs. Finally, both simulation and experimental results verify the effectiveness of the presented method.

关键词： Cascaded H-bridge inverter(CHBI) Hybrid modulation strategy(HMS) Capacitor voltage balancing DClink voltage fluctuation Supercapacitor(SC)

NODULATION TRIO in Medicago truncatula:Unveiling the redundant roles of MtLYK2,MtLYK3,and MtLYK2bis

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Journal of Integrative Plant Biology 2024年第8期66卷 1553-1556页

作者： yaohua li Yanwen Zhao Ziang Yan Ru Dong Haixiang Yu Hui Zhu Yangrong Cao National Key Lab of Agricultural Microbiology Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhan 430070China

The legume–rhizobial symbiosis is a distinctive model in plant–microbe *** being foreign invaders,rhizobia are acknowledged as“friends”by compatible host plants,leading to mutualistic endosymbiosis(Cao et al.,2017).

关键词： mutual spite redundant

Upregulation of the glycine-rich protein-encoding gene GhGRPL enhances plant tolerance to abiotic and biotic stressors by promoting secondary cell wall development

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Journal of Integrative Agriculture 2024年第10期23卷 3311-3327页

作者： Wanting Yu Yonglu Dai Junmin Chen Aimin liang Yiping Wu Qingwei Suo Zhong Chen Xingying Yan Chuannan Wang Hanyan Lai Fanlong Wang Jingyi Zhang Qinzhao liu Yi Wang yaohua li lingfang Ran Jie Xiang Zhiwu Pei Yuehua Xiao Jianyan Zeng College of Agronomy and Biotechnology Southwest UniversityChongqing 400715China Engineering Research Center of South Upland Agriculture Ministry of EducationChongqing 400715China Chongqing Key Laboratory of Crop Molecular Improvement Chongqing 400715China Academy of Agricultural Sciences Southwest UniversityChongqing 400715China

Abiotic and biotic stressors adversely affect plant survival,biomass generation,and crop *** the global availability of arable land declines and the impacts of global warming intensify,such stressors may have increasingly pronounced effects on agricultural ***,researchers face the overarching challenge of comprehensively enhancing plant resilience to abiotic and biotic *** secondary cell wall plays a crucial role in bolstering the stress resistance of *** increase plant resistance to stress through genetic manipulation of the secondary cell wall,we cloned a cell wall protein designated glycine-rich protein-like(GhGRPL)from cotton fibers,and found that it is specifically expressed during the period of secondary cell wall ***,this protein differs from its Arabidopsis homolog,AtGRP,since its glycine-rich domain is deficient in glycine *** is involved in secondary cell wall *** of GhGRPL enhances lignin accumulation and,consequently,the thickness of the secondary cell walls,thereby increasing the plant’s resistance to abiotic stressors,such as drought and salinity,and biotic threats,including Verticillium dahliae ***,interference with GhGRPL expression in cotton reduces lignin accumulation and compromises that *** together,our findings elucidate the role of GhGRPL in regulating secondary cell wall development through its influence on lignin deposition,which,in turn,reinforces cell wall robustness and *** findings highlight the promising near-future prospect of adopting GhGRPL as a viable,effective approach for enhancing plant resilience to abiotic and biotic stress factors.

关键词： glycine-rich protein-like secondary cell wall abiotic stress biotic stress stress resistance

近代国际商品进口冲击与国内劳资冲突:基于1928-1936年上海各行业的分析

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中国经济史研究 2024年第4期 144-162页

作者：李耀华狄丹阳上海财经大学经济学院上海200433 中国经济思想发展研究院南京财经大学金融学院南京210023

近代国际商品进口冲击是否会影响国内劳资冲突?本文基于近代《中国旧海关史料(1859-1948)》和上海劳资冲突微观统计数据,实证检验了国际商品进口冲击对国内劳资冲突的影响。结果发现,近代商品进口增多会显著增加国内劳资冲突。从影响机... 详细信息

近代国际商品进口冲击是否会影响国内劳资冲突?本文基于近代《中国旧海关史料(1859-1948)》和上海劳资冲突微观统计数据,实证检验了国际商品进口冲击对国内劳资冲突的影响。结果发现,近代商品进口增多会显著增加国内劳资冲突。从影响机制分析,这是进口商品冲击了国内市场,导致国内企业经营困难,随后企业无论是采取裁减劳工还是降低工人日工资的方式应对困难,都会带来劳资之间冲突的增加。

关键词：商品进口劳资冲突近代上海

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变长分段直线感应电机数学建模

中国电机工程学报 2024年第13期44卷 5338-5347,I0027页

作者：徐飞李子欣孔甘霖史黎明李耀华中国科学院电力电子与电气驱动重点实验室(中国科学院电工研究所) 北京市海淀区100190 中国科学院大学北京市石景山区100049 齐鲁中科电工先进电磁驱动技术研究院山东省济南市250100

变长分段直线感应电机参数具有不连续、快速时变及强耦合特性,这给电磁暂态建模带来挑战。该文引入3种时变因子推导出具有参数时变特性的变长分段直线感应电机数学表达式。通过分析变长分段直线感应电机定子与动子的电磁耦合特性及时变... 详细信息

变长分段直线感应电机参数具有不连续、快速时变及强耦合特性,这给电磁暂态建模带来挑战。该文引入3种时变因子推导出具有参数时变特性的变长分段直线感应电机数学表达式。通过分析变长分段直线感应电机定子与动子的电磁耦合特性及时变因子与状态变量之间的耦合关系,建立定子、动子及时变因子相互解耦的数学模型。仿真结果表明,该数学模型计算的电压、电流和速度与有限元计算结果差别小于6%,验证了数学模型的准确性。硬件在环实验结果表明,在高速工况下数学模型可以准确模拟系统的电磁暂态特性,验证了数学模型的解耦能力及数值运算稳定性。

关键词：变长分段直线电机时变因子解耦数学建模

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感应电能传输系统多并联拾取模块电流和输出功率均衡方法

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电力系统自动化 2024年第5期48卷 120-127页

作者：杨继鑫史黎明殷正刚范满义李耀华中国科学院电力电子与电气驱动重点实验室(中国科学院电工研究所) 北京市100190 中国科学院大学北京市100049

大功率感应电能传输系统通常采用多并联拾取模块结构。然而,多并联拾取模块参数不一致,会导致各个拾取模块的电流和输出功率不均衡,从而降低系统效率,严重时会因模块过流而造成系统故障。为解决该问题,文中提出一种基于并联拾取模块补... 详细信息

大功率感应电能传输系统通常采用多并联拾取模块结构。然而,多并联拾取模块参数不一致,会导致各个拾取模块的电流和输出功率不均衡,从而降低系统效率,严重时会因模块过流而造成系统故障。为解决该问题,文中提出一种基于并联拾取模块补偿电容器的多并联拾取模块电流和输出功率均衡方法。首先,介绍了传统感应电能传输系统与所提出的感应电能传输系统拓扑的特性。然后,分别分析了互感、拾取线圈自感及内阻对电流分布和系统效率的影响。最后,通过4个并联拾取模块的感应电能传输系统实验平台验证了所提方法的有效性。实验结果表明,采用所提方法时多并联拾取模块的电流和输出功率基本一致,并且相比传统感应电能传输系统,系统效率最高提升了2.21%。

关键词：感应电能传输系统多并联拾取模块补偿电容器电流均衡输出功率均衡系统效率

基于改进区间法的含多裂纹铝合金蒙皮扩展寿命区间研究

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安全与环境学报 2024年第6期24卷 2238-2246页

作者：李耀华王若丁耿亚南中国民航大学交通科学与工程学院天津300300 中国民航大学航空工程学院天津300300

飞机机身蒙皮的多部位损伤(Multiple-Site Damage, MSD)一直以来都是飞机损伤容限设计与后期维修分析重点考虑的问题之一。为了研究MSD的寿命区间,结合区间理论和区间运算公式、泛灰数理论和泛灰数运算公式及两个运算公式之间的关系,得... 详细信息

飞机机身蒙皮的多部位损伤(Multiple-Site Damage, MSD)一直以来都是飞机损伤容限设计与后期维修分析重点考虑的问题之一。为了研究MSD的寿命区间,结合区间理论和区间运算公式、泛灰数理论和泛灰数运算公式及两个运算公式之间的关系,得到可以消除区间运算扩张问题和泛灰数运算失误问题的区间数-泛灰数之间新的转换模型。综合考虑新的转换模型、Paris公式、材料属性、材料尺寸和载荷性质等影响因素,最终得到了2024-T3铝合金板材的MSD裂纹扩展寿命区间:厚度为1.6 mm、不限制长宽时的寿命区间为[90 531, 143 689],厚度1.6 mm、长度240 mm、宽度60 mm时的寿命区间为[11 427, 114 071]。通过验算经典数学算例证明了所研究模型可以消除运算扩张问题和运算失误问题,使运算结果更精确;并进行了三种不同裂纹角度下的MSD裂纹扩展寿命试验,试验结果与理论预测的MSD裂纹扩展寿命区间值相吻合,证明了所研究模型的正确性和有效性。所研究模型可以为MSD裂纹扩展寿命预测和分析提供指导。

关键词：安全工程多部位损伤(MSD) 区间运算泛灰数运算寿命区间 2024-T3铝合金

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蒺藜苜蓿LysM类受体激酶的研究进展

华中农业大学学报 2024年第4期43卷 3-11页

作者：李耀华张蕊刘鲡朱辉曹扬荣农业微生物资源发掘与利用国家重点实验室/湖北洪山实验室/华中农业大学生命科学技术学院武汉430070

LysM类受体激酶属于多基因家族,其胞外域直接参与几丁质、肽聚糖和脂壳寡糖等糖化合物的感知,从而激活植物免疫或共生信号转导。豆科模式植物蒺藜苜蓿中第1个LysM受体基因LYK3的功能于2003年被表征。此后,越来越多的LysM类受体激酶的功... 详细信息

LysM类受体激酶属于多基因家族,其胞外域直接参与几丁质、肽聚糖和脂壳寡糖等糖化合物的感知,从而激活植物免疫或共生信号转导。豆科模式植物蒺藜苜蓿中第1个LysM受体基因LYK3的功能于2003年被表征。此后,越来越多的LysM类受体激酶的功能相继被鉴定。本文总结了蒺藜苜蓿LysM类受体激酶家族基因功能特征,综述了蒺藜苜蓿LysM类受体激酶家族分别在根瘤共生、菌根共生和免疫感知等方面的研究进展。研究发现,蒺藜苜蓿LysM类受体激酶家族基因数量的扩张导致了功能分化,但也存在部分基因间功能冗余现象。此外,研究还揭示了免疫与共生信号在LysM类受体激酶介导的受体感知层面存在着密切的交联,为后续研究蒺藜苜蓿中LysM类受体激酶家族基因提供有效参考。

关键词：蒺藜苜蓿 LysM类受体激酶根瘤共生菌根共生免疫感知

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