Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power testing.This offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 MHz.Adjusting the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity losses.We performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during conditioning.Multiphysics simulations indicated that increased cavity temperature did not affect frequency variation.Upon completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical calculation.Conditioning utilized efficient automatic range scanning and standing wave resonant methods.To fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was necessary.Notably,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

High RF power tests of the first 1.3 GHz fundamental power coupler prototypes for the SHINE project

The Shanghai High Repetition Rate XFEL and Extreme Light Facility(SHINE)project will use 6001.3 GHz fundamental power couplers,which are modified based on TTF-Ⅲ power couplers,for continuous-wave operation with input power up to approximately 7 kW.The first batch of 20 sets of 1.3 GHz coupler prototypes was fabricated from three domestic manufacturers for the SHINE project.To better characterize the radio frequency conditioning phenomena for validating the performance of power couplers,a room temperature test stand was designed,constructed,and commissioned for the SHINE 1.3 GHz power couplers.In addition,a horizontal test cryostat was built to test the 1.3 GHz superconducting cavities,fundamental power couplers,tuners,and other components as a set.The results of these tests indicate that the 1.3 GHz couplers are capable of handling up to 14 kW continuous waves.Herein,the main aspects of the radio frequency design and construction of the test stand,along with the test results of the high-power conditioning of the 1.3 GHz couplers,are described.

Design optimization of 3.9GHz fundamental power coupler for the SHINE project

The third harmonic superconducting cryomodule is being designed for the Shanghai High repetition rate XFEL and Extreme light facility(SHINE)project,which is under construction.In contrast to the European X-ray Free Electron Laser(E-XFEL)project,the 3.9 GHz cryomodules in the SHINE project will operate in the continuous wave regime with higher radio frequency average power for both cavities and couplers.We propose a 3.9 GHz fundamental power coupler with an adjustable antenna length,for satisfying the SHINE project requirements.Here,we describe the 3.9 GHz fundamental power coupler's design considerations and power requirements for various operating modes of the SHINE Linac.We also present the results of the radio frequency simulation and optimization,including the studies on multipacting and thermal analysis of the proposed 3.9 GHz coupler.

A phenomenological model of the fundamental power coupler for a superconducting resonator

In this study,a phenomenological model of the radio frequency(RF)behavior of a superconducting cavity fundamental power coupler is proposed by analyzing the simulation results of a transient beam-loading process in an extremely overcoupled superconducting cavity.Using this phenomenological model,the calculation of the transient reflected power from a superconducting cavity under beam loading can be mathematically simplified to algebraic operations without solving the differential equation governing the transient beam-loading process,while maintaining the calculation accuracy.Moreover,this phenomenological model can facilitate an intuitive understanding of the significant surge in the time evolution of reflected power from a superconducting cavity in certain beam-loading processes.The validity of this phenomenological model was carefully examined in various beam-loading processes and cavity conditions,and the method based on this phenomenological model was utilized in the transient RF analysis of the superconducting cavity system of the CAFe Linac,achieving satisfactory results.

Development of fundamental power coupler for C-ADS superconducting elliptical cavities

5-cell elliptical cavities have been selected for the main linac of the China Accelerator Driven subcritical System （C-ADS） in the medium energy section. According to the design, each cavity should be driven with radio frequency （RF） energy up to 150 kW by a fundamental power coupler （FPC）. As the cavities work with high quality factor and high accelerating gradient, the coupler should keep the cavity from contamination in the assembly procedure. To fulfil the requirements, a single-window coaxial type coupler was designed with the capabilities of handling high RF power, class 10 clean room assembly, and heat load control. This paper presents the coupler design and gives details of RF design, heat load optimization and thermal analysis as well as multipacting simulations. In addition, a primary high power test has been performed and is described in this paper.

Research of Magnetic Coupler Array for IPT System

The advance of Inducive Power Transfer (IPT) system is capable to transfer large power across an air gap of sufficient distance, but the power level and charging area of receiver are limited by the magnetic coupler of IPT system. This paper analyses the correlative factors which effect maximum output power (Pm), it reveals Pm is inversely proportional with magnetic flux of power receiving coils. New ferrite array structure is proposed as the basic part of magnetic coupler that focusing on enhancing the equilibrium of magnetic flux distribution at charging area and increasing power transfer distance. The method of winding on ferrite array is quite flexible and the power transmission distance can be increased by changing the mode of ferrite array windings while magnetic field uniform is reduced, users can chose the suitable mode of winding for different IPT system. Finally the validity of theory analysis is tested by a 3D finite element modeling tool.

High-frequency fused high-voltage arc tapering process power supply for of fiber

The performance of the optical fiber coupler prepared with fused biconical taper method is determined by the quality of fused stretching. Besides, the stable high-temperature heat source is the essential guarantee for fused stretching process to go smoothly. The way of using AC （alternating current） arc as the heat source is proposed in this article. In addition, the paper also introduces high-frequency high-voltage power supply with the characteristics of constant current and restricted voltage, which is composed of preceding voltage regulation part and following inverter.

光功率均分耦合器离子交换平面光波导的温度应力特性研究

文章以1×5 PLC-MMI光功率均分耦合器为例,利用自成像理论和数值仿真方法,分析离子交换平面光波导无源器件的温度应力特性。研究了工作于850nm时器件各端口插入损耗、附加损耗与多模波导区长度和折射率变化的关系,分析了由于环境温度变化和外部应力而引起的波导变形和折射率变化,得到了因此而出现的光纤-波导耦合损耗、双折射等对MMI功率均分特性的影响。研究结果表明,文章研制的1×5 PLC-MMI光功率均分耦合器性能稳定,环境和应力对其影响小。

背向散射光测量中的平衡式多级低噪声放大器设计

针对激光陀螺谐振腔背向散射光测量中的背向散射光模式信号获取需要特定频段的低噪声放大器问题,提出了一种平衡式多级低噪声放大器。该低噪声放大器采用平衡式多级级联结构,设计专用正交耦合器以实现与光电器件的共轭匹配,基于负反馈方式进行稳定性调整,对偏置电路进行了噪声优化,基于噪声和增益选择阻抗点,从功率流传输的角度分析并对正交耦合器结构做出创新。最终达到了“阻抗匹配,噪声最小”的设计目标。验证表明,在2.3 GHz~2.7 GHz增益可达20 dB,增益平坦度约为3 dB,整体输入驻波比小于1.50,对光电探测器输出噪声有明显的抑制效果。设计结果可参考应用在高频光电器件信号放大、混频器设计和TR组件等场景,解决普通单支路低噪声放大器增益较低和噪声较大的问题。

高功率高效率速调管输出耦合器的优化与设计

输出耦合器作为速调管关键部件,其性能直接关系到速调管的整体表现。然而,耦合器故障却是速调管及多种真空电子设备中最为常见的问题之一,特别是在高连续波功率运行场景下,这一问题更为突出。针对连续波650 MHz/800 kW高效率速调管,对输出耦合器进行优化设计,并在单注和多注速调管耦合器测试方面取得了重要突破:单注速调管输出耦合器在连续波模式下的测试功率已达到690 kW以上,为了进一步增加功率容量,采用T-bar结构过渡,并对耦合器进行优化设计,使陶瓷附近电场分布更均匀;而多注速调管矩形波导窗输出耦合器最高测试功率达到全驻波115 kW。此外,通过对耦合器的结构、材料以及散热方式进行分析与优化,积极探索提升耦合器功率容量的多种可能途径,进一步增强了速调管的稳定性和可靠性。

太赫兹折叠波导慢波电路及功率合成技术

针对太赫兹频段行波管输出功率较小的瓶颈以及对紧凑型设计的明确需求,提出一种管内功率合成的0.34 THz折叠波导行波管结构。首先,对太赫兹折叠波导慢波结构的高频特性进行了研究,通过仿真计算得到了其色散特性和耦合阻抗,0.34 THz处归一化相速度为0.248,耦合阻抗为0.46Ω;其次,提出了用于管内功率合成的3 dB定向耦合器结构设计,分析表明,其在0.31~0.368 THz范围内,幅度平衡度在±0.19 dB以内,隔离度优于24 dB;最后,完成了基于3 dB定向耦合器管内功率合成的折叠波导行波管基本结构设计并构建了仿真模型,仿真结果表明,最大输出功率为9.16 W,增益为26.6 dB,3 dB带宽达到21 GHz。作为对比,单个折叠波导行波管输出功率为6.18 W,故管内合成的折叠波导行波管的输出功率是单个行波管输出功率的1.48倍;此外,与采用常规外置功率合成结构的双行波管组件设计相比,管内功率合成折叠波导行波管的横向尺寸至少缩减了56.5%。

基于微带双脊间隙波导技术的Ka波段六端口网络电路

面向毫米波高精度雷达探测应用,文中提出了一种基于微带双脊间隙波导技术的六端口网络电路。设计了基于微带双脊间隙波导的功分器和耦合器电路,提出了微带双脊间隙波导至微带线的新型过渡转换结构,并基于简化的六端口网络原理框图,将所设计的功分器、耦合器以及过渡转换结构进行有机组合,实现了所设计的Ka波段六端口网络电路。实验测试结果表明:在所设计的37.5 GHz~42.5 GHz频率范围内,输入端口1与四个输出端口间的相位差均在±2.5°以内,输入端口2与四个输出端口间的相位差均在±5°内,工作中心频率处的输入输出间插入损耗约为7.3 dB。实验与仿真结果吻合较好。

基于副边解耦极板的电容式无线电能传输系统拾取端失谐评估

对于电容式无线电能传输(CWPT)系统,准确评估拾取端回路的失谐程度是维持系统谐振稳定的前提。然而,由于系统拾取端的感应电压无法被直接观测,难以通过测量感应电压和回路电流间的相位差来评估拾取端回路的失谐程度。文中提出一种能够间接测量拾取端感应电压相位信息,评估拾取端回路失谐程度的CWPT系统。基于Z参数建立三端口CWPT系统的数学模型和等效电路,并依托该模型提出一种基于副边解耦极板的耦合机构。分析在感应电压测量和失谐程度评估过程中存在的误差,提出拾取端回路失谐程度的评估校正方法。搭建了带有副边解耦极板的CWPT系统原理样机,实验结果表明,拾取端谐振时的失谐程度评估误差不超过1Ω,拾取端感性/容性失谐时的失谐程度评估误差分别小于2%和5%。

水下机器人磁耦合无线电能传输技术研究进展

水下机器人已成为海底设施巡检和海洋环境调查的关键装备,海底无线充电基站是解决机器人原位电能补给的有效方案。概述磁耦合式水下无线电能传输技术的原理,针对电磁耦合器结构、补偿网络拓扑、涡流损耗分析等主要问题,综述水下无线电能传输技术的研究现状,总结海底无线充电基站的国内外应用进展,并展望水下无线电能传输技术在基础理论和应用方面的发展方向。

一种全周转向式非接触电连接器设计与应用

磁耦合器是水下无线电能传输(UWPT)系统中最重要的部件,其配置决定了适用场景,参数设计和优化将直接影响系统的整体输出功率和效率。提出了一种应用于水下潜航器的新型全周转向式非接触电连接器方案,球头与球座之间除轴向旋转外,还可实现径向旋转,使整个系统具有方便可靠、操作安全、移动灵活等特点。将提出的电连接器接入UWPT系统样机进行验证,实现了在0°至45°径向偏移角度下的无线电能传输,使得系统总效率保持在85%以上。

车用机电复合储能系统的能量特性分析

针对混合动力汽车制动能量回收-释放过程中多元能量转化形式限制的问题,本工作提出了一种新型的车用机电复合储能系统。车辆减速时,系统可将一部分汽车后轮传递的动能转化为电化学能存储于电池中,其余部分直接以动能形式储存。首先,分析了该系统在汽车加速、减速工况下的能量转换特性,推导出电磁耦合器在额定状态下机械端口、电气端口的转换功率。其次,基于MATLAB/Simulink中建立的系统模型,讨论了汽车以60 km/h初速度减速至42 km/h下巡航时系统的功率特性和能量特性,减速过程中电磁耦合器输出功率由1.257 kW增大到1.546 kW,其传递的功率约为额定功率的1.14~1.41倍。此过程中,该系统可将来自汽车后轮动能的72.34%直接储存于飞轮中,27.66%的能量经电磁耦合器电气端口转换后储存于电池中。最后,搭建了车用机电复合储能系统运行试验台,验证了系统的合理性。

基于旋转磁场耦合的非对称式无线电能传输系统

为了解决无线电能传输系统耦合机构偏移偏转致使耦合系数和传输能效骤降的问题,提出了一种基于旋转磁场耦合的非对称式WPT系统。所提出的双层正交DD发射机构用以激发旋转耦合磁场,交叉偶极式接收机构可实现旋转磁场的充分拾取。围绕DQDD-CD非对称耦合机构,分析了发射线圈激发磁场的旋转分布特性以及接收线圈偏移偏转位置下拾取磁通的耦合路径;构建了双能道谐振拓扑并推导了谐振元件参数配置条件以及系统传输能效表达式;给出了获得最高耦合系数的线圈绕制、位置和尺寸3类特征参数的配置方法,分析了偏移偏转位置下DQDD-CD耦合机构的互感及耦合系数变化规律,分析结果表明DQDD-CD机构相比于现有6种典型耦合机构具有更全方位和更宽范围的抗偏移偏转性能。最后,在水平偏移50%和垂直偏转90°范围内的情况下,建立了500 W实验样机,传输间距为130 mm,验证了DQDD-CD磁耦合机构的抗偏移偏转性能和系统传输能效性。

无线充电系统旋转式电磁耦合器损耗计算及热点温度研究

电磁耦合器是实现无线电能传输(WPT)技术的核心元件,其工作温度决定了系统运行的稳定性与使用寿命。为此该文以抗偏移能力强的旋转式电磁耦合器为研究对象,针对该电磁耦合器在非正弦激励下损耗及温度精确计算的问题,同时为避免大量实验数据繁琐采集过程,利用瞬态电磁-热流场双向间接耦合方法,建立考虑绝缘引起的匝间距及温度对材料属性影响的三维电磁场仿真模型,而后将电磁损耗计算结果作为载荷耦合至热流场中并建立对应关系,实现对热点温度计算。仿真与实验结果表明,物理模型的热点温度与测量值最大误差为5.15%,仿真得出的温升分布规律能较准确地展示实际情况,验证了物理仿真模型的合理性,可为旋转式电磁耦合器的散热设计提供依据,在工程应用中具有一定指导意义。

VHF频段大功率定向功率合成器设计

在100~350 MHz频段的1200 W以上量级的大功率功放模块,需要使用包括四路功率合成器和定向耦合器在内的多个器件。为实现大功率容量、小体积、宽频带和易于模块联调的设计目标,设计了VHF频段大功率定向功率合成器。通过采用反向平衡磁路设计有效降低了磁心损耗,实现了大功率条件下的宽带小体积传输线变压器设计;通过采用带状线结构电路与传输线变压器合成电路一体集成的方式,实现了同时具备四路功率合成和正、反向定向耦合功能的宽带大功率定向功率合成器。功放模块联试显示,在100~350 MHz全频段可实现1200 W长时间稳定工作,占用体积比传统多个组合器件减小了60%以上。

广播电视发射台站备用电源系统设计与优化

备用电源系统能够有效降低因供配电系统故障导致的播出事故的概率,是广播电视发射台站安全播出的重要保证。以广播电视台发射台站供配电改造工程为例,提出一套改进型备用电源系统设计方案,利用PC817光电耦合器实时检测掉电因子,并以外围接口控制器(Peripheral Interface Controller,PIC)系列单片机作为主控制器来调节切换装置,以实现备用电源系统的自主优化。