作者机构:
[孙益辉; 田原] School of Electrical Engineering, University of South China, Hunan, Hengyang, 421001, China;[易灵芝] School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, 430073, China;[夏云芝] School of Cyber Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
摘要:
模块化多电平换流器(Modular Multilevel Converters,MMC)具有维护方便,易扩容等优点,在柔性直流输电(High Voltage Direct Current,HVDC)、电网谐波治理等领域得到广泛应用。但其子模块中的分散电容,在实际使用中会产生谐波环流,影响了模块电容电压波动,降低换流器的安全裕度和经济性。文章首先介绍了MMC组成结构;然后通过建立桥臂瞬时功率方程,分析环流产生机理,并得出桥臂环流中存在二次谐波分量的结论,通过控制直流侧电压与桥臂等效输出电压之间的差值,调节环流中的谐波分量,进而将现阶段国内、外环流抑制方法分为间接环流抑制方法与直接环流抑制方法,并对环流的利用也做了相关阐述。最后对环流抑制存在的问题进行总结与展望。
作者机构:
[谭清懿; 杨开建; 乔冠瑾] Department of Electrical Engineering, University of South China, Hengyang, 421001, China;[杜丹] Department of Mathematics and Physics, University of South China, Hengyang, 421001, China;[潘光祖; 周华; 龚学余] Department of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
通讯机构:
[Du, D.] D;Department of Mathematics and Physics, China
作者机构:
[阳璞琼; 刘波] School of Electrical Engineering, University of South China, Hengyang, 421001, China;[谢亚红; 韦江龙; 潘军军; 蒋才超; 胡纯栋] Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
通讯机构:
[Jiang, C.] I;Institute of Plasma Physics, China
作者机构:
[吴荣燕; 阳璞琼] School of Electrical Engineering, University of South China, Hengyang;421001, China;[周剑良] School of Nuclear Science and Technology, University of South China, Hengyang;[吴荣燕; 周剑良; 阳璞琼] 421001, China
作者机构:
[Weiwei X.; Nini S.; Xiangjiang W.] School of Mechanical Engineering, University of South China, Hunan, Hengyang, 421001, China;Hunan Provincial Key Laboratory of Ultra-Fast Micro-Nano Technology and Advanced Laser Manufacturing, Hunan, Hengyang, 421001, China;[Zhiyong C.] School of Electrical Engineering, University of South China, Hunan, Hengyang, 421001, China;[Xinling S.; Xinlin W.] School of Mechanical Engineering, University of South China, Hunan, Hengyang, 421001, China<&wdkj&>Hunan Provincial Key Laboratory of Ultra-Fast Micro-Nano Technology and Advanced Laser Manufacturing, Hunan, Hengyang, 421001, China
摘要:
为了研究激光切割UO2陶瓷芯块-316Ti不锈钢复合结构温度场的分布,考虑了材料的热物性参数与温度的关系,运用ANSYS有限元软件模拟了该复合结构的激光切割过程,通过ANSYS的Fluent模块实现激光热源C语言程序的UDF加载与编译。研究了不同激光切割工艺参数下的温度分布云图,结果表明:温度分布主要呈现为类彗尾状;最高温度集中在切割热源中心处,工件表面的最高温度随着激光功率的增加和切割速度的降低而升高;当激光功率过小或切割速度过大时,工件会因热量输入不足而切不透;当激光功率过大或切割速度过小时,切缝会因材料熔化区域变大而变宽。仿真结果可以对实际切割过程的工艺参数优化提供参考。 To investigate the temperature-field distribution of UO2 ceramic pellets-316Ti stainless steel composite structure during laser cutting processes, considering the relationship between thermal physical parameters and the temperature of materials, we simulated the laser cutting process for the composite structure using ANSYS finite-element software. User defined function loading and compiling of laser heat source C language program was realized using the Fluent module of ANSYS. The temperature distribution cloud maps were studied at different cutting parameters. The results show that temperature distribution is mainly expressed as comet-like state. Maximum temperature is concentrated at the center of the cutting heat source, and it increases with increasing laser power and decreasing cutting speed. When the laser power is too low or cutting speed is too high, the workpiece due to insufficient heat input will not be cut through. If the laser power is too high or cutting speed is too low, the kerf width widens due to the lager material melting area. The simulation results can be used to optimize the parameters of the actual cutting process.
作者机构:
[张洪明; 郝强旺; 戴超; 李军; 符佳; 李颖颖; 王福地; Lyu B.] Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031, China;University of Science and Technology of China, Hefei, 230026, China;School of Electrical Engineering, University of South China, Hengyang, 421001, China;[肖君; 杨洋] Institute of Modern Physics, Fudan University, Shanghai, 200433, China;[宾斌] Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031, China, University of Science and Technology of China, Hefei, 230026, China, School of Electrical Engineering, University of South China, Hengyang, 421001, China
通讯机构:
[Lyu, B.] I;Institute of Plasma Physics, China
关键词:
电子束离子阱;高电荷态离子;低温超导
摘要:
提出了一种基于传导冷却的紧凑型中能段电子束离子阱杂质光谱研究平台的系统设计方案,用于未来聚变堆上金属杂质原子光谱研究。系统设计主要包括磁场计算、内电极设计、光谱仪设计及其他辅助系统设计。通过使用COMSOL仿真软件对磁场和电子束进行了辅助设计,仿真结果显示,合适的设计参数可以使电子束离子阱(Electron Beam Ion Trap,EBIT)漂移管中心得到1.0 T的均匀磁场强度,电子束可以在漂移管中被约束并通过漂移管到达收集极,此设计可为进一步工程设计提供设计参数参考。
作者机构:
[屈星; 盛义发; 苏泽光; 赵宇红] School of Electrical Engineering, University of South China, Hengyang;Hunan Province;421001, China;[李欣然] School of Electrical and Information Engineering, Hunan University, Changsha;410082, China
通讯机构:
School of Electrical Engineering, University of South China, Hengyang, Hunan Province, China
作者机构:
[屈星; 盛义发; 肖金凤; 徐祖华] School of Electrical Engineering, University of South China, Hengyang;421001, China;[李欣然] School of Electrical and Information Engineering, Hunan University, Changsha;410082, China;[屈星; 盛义发; 肖金凤; 徐祖华] 421001, China
通讯机构:
[Qu, X.] S;School of Electrical Engineering, China
关键词:
负荷建模;电池储能系统;广义负荷;广义综合负荷模型;电力系统
摘要:
针对含电池储能系统(batter energy storage system,BESS)的配电网参与电网仿真所需的广义综合负荷模型展开研究。阐述了BESS的仿真数学模型,搭建了基于MATLAB/Simulink的BESS仿真平台;通过对BESS暂态运行特性的仿真分析,提出了一种面向负荷的BESS等效模型并进行了检验;建立了考虑BESS的配电网广义综合负荷模型,该广义综合负荷模型由BESS等效模型和经典综合负荷模型(composite load model,CLM)并联构成;通过多场景的仿真分析,检验了提出的广义综合负荷模型的有效性和模型参数稳定性。
作者机构:
[屈星; 盛义发; 肖金凤; 文娟; 邓攀] School of Electrical Engineering, University of South China, Hengyang;Hunan;421001, China;[李欣然] School of Electrical and Information Engineering, Hunan University, Changsha;410082, China