A real-time calibration method based on time-to-digital converter for accelerator timing system

The high-intensity heavy-ion accelerator facility(HIAF)is a scientific research facility complex composed of multiple cas-cade accelerators of different types,which pose a scheduling problem for devices distributed over a certain range of 2 km,involving over a hundred devices.The white rabbit,a technology-enhancing Gigabit Ethernet,has shown the capability of scheduling distributed timing devices but still faces the challenge of obtaining real-time synchronization calibration param-eters with high precision.This study presents a calibration system based on a time-to-digital converter implemented on an ARM-based System-on-Chip(SoC).The system consists of four multi-sample delay lines,a bubble-proof encoder,an edge controller for managing data from different channels,and a highly effective calibration module that benefits from the SoC architecture.The performance was evaluated with an average RMS precision of 5.51 ps by measuring the time intervals from 0 to 24,000 ps with 120,000 data for every test.The design presented in this study refines the calibration precision of the HIAF timing system.This eliminates the errors caused by manual calibration without efficiency loss and provides data support for fault diagnosis.It can also be easily tailored or ported to other devices for specific applications and provides more space for developing timing systems for particle accelerators,such as white rabbits on HIAF.

A LOW POWER TIME-TO-DIGITAL CONVERTER FOR ALL-DIGITAL PHASE-LOCKED LOOP

Time-to-Digital Converter (TDC) is a key block used as the phase/frequency detector in an All-Digital Phase-Locked Loop (ADPLL). Usually, it occupies a large proportion of ADPLL's total power consumption up to about 30% to 40%. In this paper, the detailed power consumption of different components in the TDC is analyzed. A Power Management Block (PMB) is presented for the TDC to reduce its power consumption. A 24-bits TDC core with the proposed PMB is implemented in HJTC 0.18 μm CMOS technology. Simulation results show that up to 84% power reduction is achieved using our proposed technique.

A high-precision and 10 bit two-step Time-to-Digital Converter for TOF application

A two-step high-precision Time-to-Digital Converter(TDC),integrated with a Single-Photon Avalanche Diode(SPAD),used for Time-Of-Flight(TOF)application,has been developed and tested.Time interval measurement is performed by the coarse counter and fine interpolator,which are utilized to measure the total periods and the residue time of the reference clock,respectively.Following a detail analysis of time precision and clock jitter in the two-step structure,the prototype TDC fabricated in GSMC 1P6M 0.18μm CMOS Image Sensor(CIS)technology exhibits a Single-Shot Precision(SSP)of 11.415 ps and a dynamic range of 216.7 ns.In addition,a pixel of the chip occupies 100μm×100μm,and the measured Integral Nonlinearity(INL)and Differential Nonlinearity(DNL)are better than±0.88 LSB and±0.67 LSB,respectively.Meanwhile,the overall power consumption of the chip is 35 mW at 1.8 V power supply.Combined with these characteristics,the designed chip is suitable for TOF-based ranging applications.

PULSE SHRINKING TIME-TO-DIGITAL CONVERTER FOR UWB APPLICATION

A kind of architecture of Time-to-Digital Converter(TDC) for Ultra-WideBand(UWB) application is presented. The proposed TDC is based on pulse shrinking, and implemented in a Field Programmable Gate Array(FPGA) device. The pulse shrinking is realized in a loop containing two Programmable Delay Lines(PDLs) or a two-channel PDL. One line(channel) delays the rising edge and the other line(channel) delays the falling edge of a circulating pulse. Delay resolution of PDL is converted into a digital output code under known conditions of pulse width. This delay resolution measurement mechanism is different from the conventional time interval measurement mechanism based on pulse shrinking of conversion of unknown pulse width into a digital output code. This mechanism automatically avoids the influence of unwanted pulse shrinking by any circuit element apart from the lines. The achieved relative errors for four PDLs are within 0.80%–1.60%.

Single-Stage Vernier Time-to-Digital Converter with Sub-Gate Delay Time Resolution

This paperpresents a single-stage Vernier Time-to-Digital Converter (VTDC) that utilizes the dynamic-logic phase detector. The zero dead-zone characteristic of this phase detector allows for the single-stage VTDC to deliver sub-gate delay time resolution. The single-stage VTDC has been designed in 0.13μm CMOS technology. The simulation results demonstrate a linear input-output characteristic for input dynamic range from 0 to 1.6ns with a time resolution of 25ps.

Principle, Modeling and Control of DC-DC Convertors for EV

DC DC convertors can convert the EV's high voltage DC power supply into the low voltage DC power supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principle and the method of design, modeling and control for DC DC convertors of EV are introduced. The method of the system response to a unit step function input and the frequency response method are applied to researching the convertor's mathematics model and control characteristic. Experiments show that the designed DC DC convertor's output voltage precision is high, the antijamming ability is strong and the adjustable performance is fast and smooth.

基于RESYS程序的TOPAZ-Ⅱ反应堆系统模拟

本文使用C++语言开发了面向先进核反应堆的通用反应堆系统分析程序RESYS,在该程序的基础上建立了热离子核反应堆电源TOPAZ-Ⅱ的模型,并对其启动瞬态和稳态工况进行了模拟。建立的TOPAZ-Ⅱ反应堆系统模型包括反应堆堆芯热工模型、热离子静态热电转换系统模型、热排放辐射散热器模型。铯热离子转换器电流密度使用Rasor模型,并使用6组缓发中子点堆动力学模型计算反应堆堆芯裂变功率随时间的变化,考虑各结构部件对反应性的影响。计算得到的稳态电功率输出与TITAM程序的计算结果较为一致,反应堆系统热电转换效率为5.04%。计算结果验证了所开发的RESYS程序以及建立的TOPAZ-Ⅱ系统模型的正确性。

深远海全直流风电汇集网络故障控制与恢复方案

针对全直流海上风场汇集网络故障处理问题,首先研究直流风电机组的故障控制策略,通过机侧换流器故障控制与卸荷电路配合的方式提高机组的安全性;其次,设计一种改进风电机组网侧DC/DC变换器拓扑,通过控制DC/DC变换器网侧电容脉冲放电进行行波测距,从而定位故障区段;最后,提出基于直流断路器的汇集网故障控制与恢复方案。利用PSCAD搭建全直流海上风电场模型,多种故障场景下的仿真验证了所提故障控制与恢复方案的有效性。

智能化转炉干法除尘水汽柔性调节装置

面对我国日益严峻的环保形势,为满足转炉烟气超低排放的要求,通过分析转炉一次烟气干法除尘的工艺流程和设备原理,研发了配置有柔性调节装置的转炉一次烟气干法除尘新工艺。柔性调节装置采用了智能化调节控制系统,通过其自有的水汽调节装置实时分析转炉状态,智能化地适应转炉的不同冶炼状态,并能及时切换运行模式。生产实践表明,柔性调节装置结构合理,安全可靠,新工艺能有效解决企业在控制成本前提下对转炉一次烟气超低排放的问题,满足环保排放指标要求的同时节约成本。

海上风电柔性直流技术研究进展与展望

本文概述了全球海上风电发展情况,从政策、规划、资源、技术角度分析了我国海上风电发展的宏观基本面。详细介绍了国内外海上风电柔性直流送出的主流技术路线和技术发展现状。针对几类新型海上风电柔直系统拓扑结构,从技术、经济性方面进行了综合比较分析,并对其工程应用潜力进行了研判。最后提出了我国海上风电柔性直流技术研究与创新发展的战略思考和建议。

特高压换流站监视云边协同计算优化研究

随着我国特高压电力系统的不断发展,特高压换流站中需要实时测量的数据呈现指数增长。针对现有保护系统数据传输不能满足数据采集实时性要求的问题,提出一种云边协同的计算架构。首先,对特高压换流站内的数据采集问题进行建模,并证明最优通信调度与计算资源分配问题是一个凹优化问题。其次,提出一种云边协同通信调度与计算资源分配方法,对具有严格延迟界限的任务在边缘从站处理,而具有宽松延迟界限的任务被传输到云端主站,实现特高压换流站中传感器数据的低传输延时通信调度与计算资源分配。仿真模拟表明采用所提方法可以使特高压换流站内通信满足任务延迟要求的概率提高了14%到30%,提高了数据传输效率。

微电网V2G双向变换器运行状态分析方法

针对现有微电网V2G双向变换器运行数据的智能监测系统抗干扰性差、监测精度低等问题,提出一种新型配电自动化监测系统架构。该系统采用集成模拟电路的实时配电系统状态估计器(distribution system state estimator,DSSE)作为监测系统的关键部件。开发的DSSE针对配微电网V2G双向变换器监测系统进行了单元优化,在变电站实时执行监控,可通过多区域状态估计算法进行协调,提高监控事件的时间效率和鲁棒性,同时也保持了可接受的精度水平。设计了针对虚假噪声信号注入防护的试验,试验结果表明,该系统对于这类攻击具有较高稳定性,能有效保护微电网V2G双向变换器运行数据的质量。

某船电源转换装置对电网绝缘监测干涉原因分析

配电板和交流不间断电源装置为电源转换装置提供主用、备用两路电源输入,简单的供电关系却造成了某船电源转换装置对电网绝缘监测干涉的现象。通过对干涉现象分析,结合设备之间的内在联系和电源转换装置两路电源转换原理以及绝缘监测的工作原理,找到固态开关的两路电源转换是造成干涉现象的根源,通过试验验证,提出可行的解决方案。

Multi-narrowband signals receiving method based on analog-to-information convertor and block sparsity

The analog-to-information convertor (AIC) is a successful practice of compressive sensing (CS) theory in the analog signal acquisition. This paper presents a multi-narrowband signals sampling and reconstruction model based on AIC and block sparsity. To overcome the practical problems, the block sparsity is divided into uniform block and non-uniform block situations, and the block restricted isometry property and sub-sampling limit in different situations are analyzed respectively in detail. Theoretical analysis proves that using the block sparsity in AIC can reduce the restricted isometric constant, increase the reconstruction probability and reduce the sub -sampling rate. Simulation results show that the proposed model can complete sub -sampling and reconstruction for multi-narrowband signals. This paper extends the application range of AIC from the finite information rate signal to the multi-narrowband signals by using the potential relevance of support sets. The proposed receiving model has low complexity and is easy to implement, which can promote the application of CS theory in the radar receiver to reduce the burden of analog-to digital convertor (ADC) and solve bandwidth limitations of ADC.

动态响应误差驱动的风机并网变流器控制参数辨识方法

为了获取更精准的双馈风机变流器暂态模型参数,保障风力发电联网运行仿真分析结果的准确性,满足新能源高占比电力系统的安全稳定运行要求,文中提出了一种输出响应误差驱动的参数辨识方法。根据双馈风机的机电暂态模型确定出待辨识的参数,实现了MATLAB与PSASP的循环调用,根据真实值下的动态响应曲线与辨识值下的动态响应曲线的误差最小来确定最终辨识值,并通过设置不同工况验证该辨识方法的有效性。

电爆桥膜换能元设计研究

基于国内外电爆桥膜换能元技术的研究现状,总结了桥膜换能元的基本结构和类型,给出了V形桥区电阻和质量的计算方法;并提出了电容放电输入和长脉冲恒流输入条件下桥膜换能元的电热致电爆换能模型,以便估算桥膜换能元温升及临界爆发参数。采用溅射镀膜方法制备了多种不同结构的桥膜芯片及其桥塞换能元,测试表明桥膜芯片的电阻偏差均小于±5%。电爆实验表明,电阻/质量为2.25Ω/0.196μg的芯片与Φ3.4mm的桥塞所集成的换能元,在24V/33μF放电下的爆发时间为87μs,瞬发度很高;5min恒流脉冲输入的不爆发电流约为0.91A,电流安全性较好。电阻/质量分别为1.03Ω/0.259μg和1.05Ω/0.095μg的芯片与Φ3.4mm的桥塞所集成的换能元,5min恒流脉冲输入的不爆发电流均大于1.32A,电流安全性较高。

DC-DC Boost变换器系统的复合模态振荡分析

以DC-DC Boost变换器系统为研究对象,引入参数激励和外部激励,建立参外联合激励多尺度耦合动力学模型。当系统表现为严格共振关系时,且参数、外部激励频率与系统固有频率存在量级差时,把两激励项转化为单一周期激励项的函数形式,将此作为慢变参数,得到广义自治快子系统。主要探究了三种典型激励频率比下系统的复合模态振荡行为,借助单参数和双参数分岔图、复杂度谱熵图、转换相图等,分析了“非对称式光滑Fold-非光滑Fold型”、“周期性对称式非光滑Fold-Fold型”等复合模态振荡的产生机理和非光滑动力学行为特性。特别地,系统在不同频率比下的运行轨线结构,穿越非光滑分界面次数,簇发分岔点等均有所变化,从而导致含不同涡卷数的复合模态振荡。该研究为相关耦合电路的簇发振荡研究提供了理论基础及辅助分析模型。

换流站交流软母线安装长度模型分析

对于中大型换流站运行系统,软母线是汇集、分配和传输电能的重要载体,由于室外空间大、气象及地质条件复杂,所以大部分采用软母线连接方式,其中软母线弧垂是检测其安装质量的重要标准,过小则会增加导线拉力,过大则会影响安全距离,同时绝缘子串重量、数量及构架高低差、档距均会对软母线弧垂产生较大的影响,简单的悬链线模型无法准确计算弧垂及对应导线的安装长度[1]。介绍了软母线弧垂的基本计算方法,并在此基础上提出复合模型,更精确计算软母线下料长度,提高软母线安装质量,保证供电质量,并将其运用于工程实际中。

基于XgBoost算法的牵引变流器柜体温度异常检测

牵引变流器是列车电气系统的重要组成部分,它直接关系到列车能否正常运行。牵引变流器的柜体温度变化可以间接的反应牵引变流器的健康状态。当前列车的牵引变流器的柜体温度的异常判断准则比较简单:通过阈值进行判断,即高于某个温度值则视为异常。但是这种方法存在如下的缺点:当阈值过高时,对温度不敏感,准确率较低;而阈值较低时,误报率较高。本文介绍了一种综合当前时刻牵引变流器冷却系统的温度和压力、列车速度、室外温度、牵引变流器的电压和电流等变量作为输入的回归算法计算温度预测值,基于XgBoost算法检测高速列车牵引变流器柜体温度异常。

海上柔性直流送出系统造价水平分析

[目的]研究海上柔性直流送出系统的造价构成及造价水平,为海上柔性直流送出系统的造价管控提供有益的探索。[方法]收集目前已开展的海上柔性直流送出系统设计及造价相关数据,采用统计分析法、费用构成法以及对比分析法等对海上柔性直流送出系统涉及的各项费用进行分析。[结果]给出了海上柔性直流送出系统典型方案的单位容量投资水平以及投资构成,提出了海上柔性直流送出系统造价水平控制的关键因素和要点。[结论]海上柔性直流送出系统的单位容量投资为3750~4600元/kW。费用构成比例从高到低依次为设备购置费、建筑工程费、其他费用和安装工程费;系统构成比例从高到低依次为海上换流站、海缆、陆上换流站和其他部分。与陆上柔性直流送出系统对比,总体差异在1.3~1.6倍。