CAS OpenIR  > 中科院上海应用物理研究所2004-2010年
上海光源数字化高频低电平系统算法研究
Alternative TitleResearch on Algorithm of Digital Low Level RF System of Shanghai Synchrotron Radiation Facility
尹成科
Subtype博士
Thesis Advisor戴志敏
2008-06-04
Degree Grantor中国科学院上海应用物理研究所
Place of Conferral上海应用物理研究所
Degree Discipline核技术及应用
Keyword高频腔 低电平控制 Iq调制解调
Abstract高频低电平控制系统(LLRF)是高频控制系统的核心,也是储存环的关键子系统。LLRF 技术经历了全模拟控制、数字加模拟控制和正在发展的全数字控制三大阶段。由于数字LLRF 系统有许多优点,目前国际上众多加速器相关实验室都在发展基于FPGA 技术的全数字LLRF。上海光源(SSRF)是中国大陆在建的第一台3.5GeV 第三代同步辐射光源,其各项指标都位居世界前列。SSRF 储存环在预制研究阶段成功地研制了全模拟的LLRF 样机,各项技术指标都达到了设计要求。根据国际上加速器LLRF 发展趋势和上海光源的需要,上海光源为储存环高频系统成功开发了全数字LLRF 系统,实现了控制高频腔幅度误差±1%以内,相位误差±1°以内的目标。开发全数字LLRF 系统需要对高频系统有全面的研究。理解高频腔的模型是进行控制的关键。在高频腔模型的基础上设计的控制算法要在FPGA 中运行,需要解决数字系统中等一系列特有问题。本论文对上海光源高频腔进行了系统模型分析和仿真。通过引入高频腔的传递函数和其在IQ 域的一阶低通表示,结合PI 控制器的系统传递函数,分析了系统闭环的稳定性,给出了系统参数极限和优化值。利用P-I 空间等高线图,分析了闭环系统的裕度、超调量、带宽、抑制度等重要系统参数随PI 参数的变化情况。分析了高频腔失谐带来的影响。本论文设计了上海光源数字化高频低电平控制系统的数字算法,包括数字PI 控制器、IQ 调制解调、去直流成分、数字移相器、直接频率合成等,分析了它们的性能,给出了算法仿真和测试结果,并给出了在FPGA 中的实现方案和在上海光源储存环上的运行情况。本文分析了时钟对控制性能的影响,提出了测量方案并给出了结果。本论文发展了non-IQ 采样控制方法,提出了一种新的算法实现,给出了系统模型并导出了其数学关系,并对其带来的系统性能改善做了分析和仿真。这种方法对LLRF 中的非线性抑制有很好的效果,并且可以使用任意的时钟采样,简化了硬件和软件的复杂度。Non-IQ 方法是提高LLRF 系统性能的重要途径之一。未来加速器对高频系统的稳定有更高的要求,所以non-IQ 控制方法有重要的研究和应用前景。本文的重点在于系统模型分析和算法设计,为SSRF 数字化低电平的自主研发提供了基本依据和支持。
Other AbstractLow Level RF is the core of RF control system and a key subsystem of storage ring. It is developing into full digital from previous analog and analog-digital hybrid system. FPGA-based full digital Low Level RF is studied in many accelerators in the world due to its advantages. Shanghai Synchrotron Radiation Facility (SSRF) is the first 3-rd 3.5GeV generation synchrotron radiation light source building in P.R. China. SSRF has built an analog Low Level RF in the preliminary study and obtain the required performance. According to the international trend in Low Level RF development and the requirement of SSRF, SSRF develops full digital Low Level RF and maintain cavity amplitude error within ±1% and phase error within ±1°. Full digital Low Level RF development requires deep research on RF system. The key is to model the RF cavity. Specifically, many problems need to be solved for algorithms designed from cavity model implementing in FPGA. This paper analyzes and simulates the system model of Low Level RF of SSRF, yields the close loop transfer function with PI regulator, analyzes the stability, and gives the limitations and optimized values of proportional and integral gains. Based on contour plot in P-I space, the margin, overshot, bandwidth and suppression are presented relating to the change of proportional and integral gains. The influence of detuning of RF cavity is also considered. This paper designs the algorithm of digital PI regulator, IQ modulation and demodulation, digital phase shifter, direct digital syntheses, etc. This paper analyzes their performances, gives implementations in FPGA and presents the measurement results in SSRF storage ring. This paper analyzes the influence of noise of clock signal, gives the measurement methods and results. This paper developments non-IQ sampling method and introduces a new implantation, gives its system model and its math, and analyzes and simulates its improvements of control performance. This method reduces the nonlinearities very well. It can work on arbitrary frequency configuration of clocks and IF and simplify the complication of software and hardware design. Non-IQ sampling method is an important way to improve Low Level RF performance to satisfy requirements of future accelerators. This paper focused on system analyses and algorithm design. This paper’s work is fundamental support for domestic development of Low Level RF of SSRF.
Pages148
Language中文
Document Type学位论文
Identifierhttp://ir.sinap.ac.cn/handle/331007/7250
Collection中科院上海应用物理研究所2004-2010年
Recommended Citation
GB/T 7714
尹成科. 上海光源数字化高频低电平系统算法研究[D]. 上海应用物理研究所. 中国科学院上海应用物理研究所,2008.
Files in This Item:
File Name/Size DocType Version Access License
尹成科博士论文.pdf(2384KB) 开放获取--Application Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[尹成科]'s Articles
Baidu academic
Similar articles in Baidu academic
[尹成科]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[尹成科]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.