调频对ICRH天线系统单铁氧体阻抗匹配效果的研究  

Effect of frequency modulation on impedance matching of single ferrite in ICRH antenna system

作　　者：杨开建 杜丹[2] 谭清懿 周华 潘光祖 乔冠瑾 龚学余[3] YANG Kaijian;DU Dan;TAN Qingyi;ZHOU Hua;PAN Guangzu;QIAO Guanjin;GONG Xueyu(Department of Electrical Engineering,University of South China,Hengyang 421001,China;Department of Mathematics and Physics,University of South China,Hengyang 421001,China;Department of Nuclear Science and Technology,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学电气工程学院,衡阳421001 [2]南华大学数理学院,衡阳421001 [3]南华大学核科学与技术学院,衡阳421001

出　　处：《核技术》2022年第4期74-80,共7页Nuclear Techniques

基　　金：国家自然科学基金(No.11205086、No.12075114);湖南省自然科学基金(No.2020JJ4515);湖南省教育厅重点项目(No.20A432、No.20A439、No.20A417);国家留学基金项目(No.202108430056);南华大学核燃料循环技术与装备湖南省协同创新中心开放基金项目(No.2019KFY23、No.2019KFZ10)。

摘　　要：采用传输线理论分析了离子回旋共振加热(Ion Cyclotron Resonance Heating,ICRH)天线耦合阻抗变化时(2~8Ω),频率反馈控制对ICRH天线系统单铁氧体调谐器阻抗匹配效果的影响。模拟结果表明:在一定条件下,优化设计铁氧体长度及天线与单铁氧体调谐器之间的机械长度(归一化长度约0.540),结合频率反馈控制,单铁氧体调谐器可将ICRH天线系统的反射系数降低在0~8.4%以内,频率反馈相对频移范围为0.146%~0.134%,系统阻抗匹配响应时间(小于1 ms)满足天线耦合阻抗的快速变化。频率反馈控制的单铁氧体调谐器,不仅有效地缩小了匹配网络的空间尺寸,而且还能增强阻抗匹配效果。相关研究结果为离子回旋共振加热天线系统的设计提供了一定理论参考。[Background] Ion cyclotron resonance heating(ICRH) is an important auxiliary heating method in tokamak. When fast plasma phenomena such as L-H mode transitions and edge localized modes(ELM), etc.,happens, a large change in the antenna coupling impedance occurs. This causes the reflected radio frequency(RF)power of ICRH antenna system increases drastically, which is an urgent problem to be solved in ICRH experiment.[Purpose] This study aims to reduce the reflected power of ICRH antenna system by an optimal design of the antenna impedance matching system. [Methods] The transmission line theory was employed to analyze the effect of frequency modulation on impedance matching of single ferrite in ICRH antenna system with varied coupling impedance in the range of 2~8 Ω. The ferrite length and the mechanical length between the antenna and single ferrite tuner(the normalized length is about 0.540) were optimized under certain conditions. [Results] Simulation results show that the reflection coefficient of the ICRH antenna system is reduced within 0~8.4% under optimized design through feedback adjustment, and the relative frequency shift is between 0.146%~0.134% whilst the system impedance matching response time is less than 1 ms. [Conclusions] Frequency feedback control of single ferrite tuner, not only effectively reduces the space size of the matching network, but also enhances the impedance matching effect. The relevant research results may provide a certain reference for the design of the ICRH antenna system.

关 键 词：离子回旋共振加热 耦合阻抗 阻抗匹配 单铁氧体调谐器 频率反馈 

分 类 号：TL62[核科学技术—核技术及应用]