新型微弱电流检测前置放大电路设计

针对常规微弱电流测量电路输入信号范围窄和微弱电流信号容易淹没在背景噪声、元器件固有噪声、电源噪声等干扰中而影响测量结果正确性问题,设计了一种新型微弱电流检测前置放大电路。该设计在分析常规跨阻抗法、对数压缩法前置放大器优缺点的基础上,通过改进设计电路和增加开关消噪电路,加宽了输入电流的测量范围、降低了检测系统的噪声影响、提高了检测速度。实验表明该电路具有较强的噪声抑制能力和较高的检测精度,有一定的实用价值。     

电源控制器及接口PSC/VME-PSI在BEPCⅡ校正子电源控制中的应用

介绍了电源控制器及接口PSC/VME-PSI在BEPCⅡ校正子电源控制中的应用以及VME-PSI机箱和转接插件PSI-RTM-D的研制.使用VME-PSI插件、VME-PSI机箱和转接插件PSI-RTM-D与电源控制器PSC进行了控制精度和稳定度实验,VME-PSI的模数转换器ADC回采的稳定度可达10-4,可以满足BEPCⅡ校正子电源控制精度和稳定度为10-4的要求.     

EAST离子回旋加热系统高功率射频放大器阳极电源的研制

离子回旋共振加热是EAST超导托卡马克核聚变实验中重要的辅助加热手段。高性能的高功率射频放大器阳极电源对整个加热系统的稳定运行起重要作用。本工作设计了基于脉冲阶梯调制（PSM）技术的阳极电源及其控制保护系统,通过采集电源的实验数据对电源的设计进行了验证。实验结果证明,本阳极电源的设计和参数选择均是合理正确的,电源的开通和关断以及控制保护的数据指标完全达到设计要求。     

基于APV25多通道读出电子学系统设计

介绍了基于APV25芯片的多通道读出电子学系统的设计方法,利用ASIC芯片与可扩展读出系统相结合,实现多通道信号的处理。在该系统中,基于PXI机箱的单个读出板可实现2 048路信号的读出及处理,并具有集成度高、低功耗、可扩展等优点。电子学测试结果表明,本系统电荷输入线性动态范围为0~12 fC,APV25等效输入噪声408 e,可适应大型物理实验微结构气体探测器、硅像素探测器等探测器的读出需求。     

CSNS引出脉冲电源控制系统设计

基于EPICS框架设计开发的CSNS引出KICKER脉冲电源控制系统,采用ZTEC数字化示波器对脉冲电源输出信号进行实时采集,通过运行在上位计算机的EPICS soft IOC实现对电源远程开/关操作和基准电压设定。性能测试的结果表明,该系统能够满足物理设计对引出KICKER脉冲电源的控制要求。     

ITER软X射线检测系统及其电磁兼容设计

国际热核聚变实验反应堆是世界上在建的最大的磁约束聚变装置托克马克装置,通过对其中软X射线的测量,可实现等离子体辐射对锯齿、色骨模等磁流体现象的物理研究和成像反演。软X射线诊断系统就是用来检测软X射线的设备。由于热核聚变时恶劣电磁环境及远距离传输,在设计信号检测系统时必须进行电磁兼容设计,以降低系统噪声、提高检测精度。本文中使用的检测电路采用差分结构实现电流信号到电压信号的转换,重点研究检测电路的实现及其电磁兼容设计。从电磁抗干扰的三要素出发,结合实验测试,针对电磁干扰的特殊性,讨论了滤波电路设计、印制电路板(Printed Circuit Board,PCB)走线、电磁屏蔽及信号接地在系统中实现。本文采用32通道板卡集成设计;信号增益提高至107 V?A-1;放大器带宽达到120 k Hz。通过测试结果可以看出,信号噪声降至8 mV。通过优化设计提高了检测电路的集成度和放大电路的增益及带宽,同时降低了检测电路的噪声。     

控制棒驱动机构响应时间测试与数据分析

针对控制棒驱动机构（CRDM）机电响应时间快且测试环境存在噪声干扰等问题,搭建了一套集PXI数据采集硬件平台和MATLAB数据分析的快速机电响应时间测试系统,能够实现对高频控制棒棒位实时信号的快速采集。利用滑动平均滤波和分区间拟合方法对棒位位移信号进行滤波和拟合,并利用快速傅里叶变换（FFT）频谱分析法验证去噪效果。结果表明,本套测试系统能被成功应用于钍基熔盐液态堆（TMSR-LF1）第一停堆系统CRDM的机电响应时间测试中,在可行性、可靠性和可用性等方面均满足CRDM机电响应时间测试要求。      

太阳X射线成像望远镜低噪声信号采集系统

太阳X射线成像望远镜是我国正在研制的第一台观测太阳10nm以下X射线活动的空间仪器,采用背照射式全耗尽型短波敏感CCD作为成像传感器,利用低噪声信号采集系统采集X射线CCD中的电荷信号,生成图像数据.文章在详细介绍X射线CCD输出结构的基础上,分析了CCD输出信号产生的过程,复位噪声产生原因和CCD输出信号的特点,引出了对信号采集系统性能指标和电路结构的要求.继而介绍了信号采集系统的各组成部分,包括前置放大电路,相关双采样电路,主放大器和AD转换电路,重点分析了相关双采样电路的原理,文中给出了各部分的设计参考和测试结果,最后总结了空间相机低噪声信号采集系统的设计原则.测试结果表明该系统成功抑制了噪声,满足太阳X射线观测的要求.     

重离子加速器数字电源回读系统

为提高数字电源回读数据的精确性、抑制噪声、降低成本,开发设计了全数字化回读系统。在本系统中,发送端的数字电源控制器通过光纤模块,按专用协议以2 kHz频率发送4种数据;接收端的数字信号采集设备接收、存储每台电源的回读数据,并标记以时间戳。系统采用有效机制保证每条数据通路的时钟同步,并提供了数据分析图形化界面。经现场测试,验证了系统的性能,达到了设计目的,使全数字化回读首次在重离子医用加速器励磁电源系统上得到成功应用。基于其较好的抗干扰性和经济性,未来可在重离子加速器中推广应用。     

储存环高精度稳流电源漂移问题的研究

分析了储存环高精度稳流电源产生漂移的原因，介绍了对电源系统给定电压，取样元件，误差放大器，调整管等相应的改进措施，经过一系列改进后，电源稳定度得到提高，进一步保证了光源的可靠供光。     

Study and Design a Strategy to Control High-Voltage Power Supply Based on PSM Technology on J-TEXT Tokamak

To energize the gyrotrons of the electron cyclotron resonance heating system, high-voltage power supply (HVPS) at 100 kV/60 A was built on J-TEXT tokamak. The HVPS was based on pulse step modulation (PSM) technology. This power supply has many advantages, including low energy storage and a short protective time in the event of a short circuit fault. In this study, we analyze and compare several common control strategies for PSM power supply. To enhance dynamic performance, the improved queue-up PSM control strategy was proposed. The control algorithm was generated using a controller based on parallel card interface extensions for instrumentation (PXI) technology, which conforms to the control, data access, and communication standard of the ITER. This controller also operates the modules of switch power supply. Experimental results show that the control system is effective and that the PXI controller can rebalance the output voltage and frequency in 60 μs when the module malfunctions under the improved system. Furthermore, the algorithm for the PXI controller is easy to develop and does not require much resources.     

一种用于旋转设备运行状态无线监测的智能无线振动传感器设计

为提高已投入运行核动力装置旋转设备的运行数据采集和状态监测能力,需要解决安装传感器和敷设配套线缆困难的问题。本文采用现场可编程门阵列（FPGA）作为主控单元,设计了一种基于Zigbee物联网通信技术的智能无线振动传感器,并给出了其电路构成、工作原理,以及嵌入式控制软件的工作流程。通过对此传感器进行性能测试,结果表明该传感器功耗低,实现了对振动信号的连续采集、智能分析与上传。该无线传感器安装简单,无需敷设供电和信号线缆,可应用于构建核动力装置旋转设备的状态监测系统。      

混合模式低噪声3 kV高压直流电源设计

高压直流电源是电离室等核辐射探测器的关键部件。针对需要3 kV左右高压的电离室,本文研制了0～3 kV连续可调的低噪声、高效率、小体积及高稳定性的高压直流电源。该高压直流电源系统采用线性与开关混合模式设计,兼顾了转换效率与低噪声。核心部分升压转换部分采用线性罗耶谐振电路与高频变压器实现,保证足够低的高压电源输出纹波。罗耶谐振电路的供电电源则由边沿时间控制型超低噪声开关稳压器LT1534提供,从而实现了混合模式高压直流电源的设计。高压直流电源输出部分采用二阶RC滤波电路进一步降低了输出电压的纹波。实测输出电压范围为0～3 kV,静态功耗为0.4 W,3 kV输出时纹波为16.55 mV,由此可知该电源可用于低噪声的核辐射探测器供电场合。     

Design and Simulation for Pre-amplifier of ITER Radial X-ray Camera

The radial X-ray camera, which is used to measure magnetohydrodynamic phenomenon and monitor edge localised mode events, is a key diagnostic system for physics studies in the international thermonuclear experimental reactor (ITER) tokamak. Considering the special requirements of physics measurements and spatial resolution, 144 detector channels are required. The board card of the pre-amplifier is designed to improve the integration, on which 16 signal channels have been integrated. In order to suppress the noise and improve the stability of the pre-amplifier, the target impedance analysis method is applied in the design of the power supply, the trans-impedance amplifier and a two-stage active low pass filter are applied in the design. Simulation with Cadence OrCAD and ANSYS SIwave has been adopted to optimize the characteristics of the pre-amplifier. A test of the pre-amplifier shows its good performance for ITER application. After optimization of the pre-amplifier, the band width is 270 kHz, the amplification is 10⁷ V/A, and the noise attenuation is ??30 dB, the noise of the pre-amplifier is reduced to 10 mV (noise of the power supply is included).     

A digital long pulse integrator for EAST Tokamak

A digital integrator has been developed to be compatible with the long pulse plasma discharges on the Experimental Advanced Superconductor Tokamak (EAST), in which the induced signal is modulated by a chopper, and a field programmable gate array (FPGA) in the 16-bit digitizer is used to realize the digital integration in real time. After rectification and integration, the drift is almost linear and stable in controlled temperature, so a period of 50 s is used to determine the linear drift rate for drift compensation. The integration data can be directly transferred to the reflective memory (RFM) card, which is installed in the same PCI eXtensions for Instrumentation (PXI) chassis, so the data transmission can be also done in real time. The test results show that the real time data transmission rate is up to 10 kHz, the integration drift is typically less than 0.4 uVs/s and drift performance is a little worse in real long pulse discharge, which can be reduced further by using more precise data acquisition.     

新型地那米加速器磁场扫描电源的研制

研制开发了开关型三角波磁场扫描电源。改进后的扫描电源比原有电源的体积缩小近２０倍，重量冯轻约１０倍，同时，扫描均匀度显著提高，且操作方便，能较好地抑制高频干扰，在防止高压打火引起仪器损坏方面效果明显，并增加了电源输出波形的显示功能。同时还探讨了扫描均匀度及保护电路的切换时间问题。     

Control strategy optimization for energy efficiency and harmonic mitigation in multi-series converters

To provide electrical power for the Research System of Superconducting Magnets (RSSMs) including the background field superconducting magnet and the tested superconducting objects, the high power phase-controlled converter will be used to develop the power supply system. However, because of its inner nonlinear feature, the current harmonics and the reactive power are injected into the AC power supply system. To improve the quality of the power supply system for RSSMs, an improved synchronous control strategy is suggested for the superconducting magnet power supply system, which comprises four series-connected six-pulse converters fed by a phase-shifting transformer, respectively. According to the proposed control strategy, the basic unit is two 12-pulse converters and the control method will be changed in terms of load fluctuations which are represented by the per unit value of converter output voltage. As a result, harmonic is greatly reduced but the power factor is also high.     

磁调制DCCT调制噪声及测量方法研究

硬X射线自由电子激光装置要求电源输出电流分辨率优于2.5×10^-6,因此,直流电流互感器（DCCT）的分辨率也必须高于以上指标,而降低DCCT调制噪声是提高其分辨率的重要方法。为降低调制噪声,本文提出了一种调制噪声的数学模型,导出了磁调制噪声的近似表达式,分析了调制噪声与相关因素的关系。同时提出了一种调制噪声的评估方法,该方法利用Matlab的periodogram命令获得噪声功率谱。利用数学模型和评估方法分析了Sinap-DCCT产品的噪声特征,结果表明,调制噪声与相关因素的关系符合数学模型的推论。据此,给出了降低DCCT调制噪声的解决方向。