Inverter power supply system for high-power twin-wire pulsed GMAW

A type of novel inverter power supply system for high-power twin-wire pulsed gas metal arc welding （GMAW） is presented mainly for dealing with the disadvantages of the conventional power supply for twin-wire pulsed GMA W of which the output power is generally difficult to increase due to limitations of the power of semiconductors and the power density of magnetic devices. In the power supplies for the master and slave arcs, the digital signal processor （DSP） TMS320F28335 is used to form the DSP- based synergic control system for parallel high-power pulsed GMA W, which achieves high-power output of two parallel inverters controlled by a single DSP ; master-slave communication is achieved by using e controller area network （eCAN）module of DSP, thas realizing anti-phase pulse output of high-power twin-wire pulsed GMA W and reducing the interference between twin arcs. The experiment results demonstrate that the designed inverter power supply system for high-power twin-wire pulsed GMAW can bring about high-power efficiency of welding, stable welding process and proper formation of welds.

Investigation on latch-up susceptibility induced by high-power microwave in complementary metal–oxide–semiconductor inverter

The latch-up effect induced by high-power microwave（HPM） in complementary metal–oxide–semiconductor（CMOS） inverter is investigated in simulation and theory in this paper. The physical mechanisms of excess carrier injection and HPM-induced latch-up are proposed. Analysis on upset characteristic under pulsed wave reveals increasing susceptibility under shorter-width pulsed wave which satisfies experimental data, and the dependence of upset threshold on pulse repetitive frequency（PRF） is believed to be due to the accumulation of excess carriers. Moreover, the trend that HPMinduced latch-up is more likely to happen in shallow-well device is proposed.Finally, the process of self-recovery which is ever-reported in experiment with its correlation with supply voltage and power level is elaborated, and the conclusions are consistent with reported experimental results.

Spectral manipulation in a high-power ultrafast fiber laser system generating ultrashort pulses with GHz repetition rate

In this work,we demonstrate the spectral manipulation in an ultrafast fiber laser system that generates ultrashort pulses with a repetition rate of 1.2 GHz and two switchable modes—a 1064-nm fundamental laser mode with a maximum output power of 66.6 W,and a 1125-nm Raman laser mode with a maximum output power of 17.23 W.The pulse width,beam quality,and power stability are carefully characterized.We also investigate a method to switch between the two modes by manipulating the duty cycle of the modulation signal.It is anticipated that this bi-mode ultrafast fiber laser system can be a promising ultrafast laser source for frontier applications,such as micromachining,bioimaging,and spectroscopy.

The Power Supply System for HL-2A Tokamak's Magnetic Field

The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC output voltage and current are 3510 V and 45 kA, respectively. All the units are operated in a pulsed mode. The pulse duration is 5 s, and the cyclic period is 15 min. The power supply system consists mainly of pulsed flywheel motor generators, rectifying transformers, thyristor converters, diode rectifiers and switches. The system incorporates many key technologies-supply equalization with two generators and four diode bridges, constant-angle phase triggers with a wide frequency range, current equalization, a status detector for the high current 6-phase converter, and advanced monitoring based on a programmable logic computer and engineering parameter measurement. The experimental results show that the performance of the power supply system satisfies the requirements of HL-2A experiments very well.

Characteristics and suppression of beam distortion in a high repetition rate nanosecond stimulated Brillouin scattering phase conjugation mirror

The stimulated Brillouin scattering phase conjugation mirror (SBS-PCM) based on liquid media is widely used in high-power laser systems due to its robust thermal load capacity, high energy conversion efficiency and improved beam quality. Nevertheless, with an increase in the pump repetition rate, thermally-induced blooming and optical breakdown can emerge, leading to distortions in the Stokes beam. In this study, we delved into the thermal effects in liquid SBS-PCMs employing hydrodynamic analysis, establishing a relationship between beam profile distortion and the thermal convection field. We calculated the temperature and convection velocity distribution based on the pump light parameters and recorded the corresponding beam profiles. The intensities of the beam profiles were modulated in alignment with the convection directions, reaching a velocity peak of 2.85 mm/s at a pump pulse repetition rate of 250 Hz. The residual sum of squares (RSS) was employed to quantify the extent of beam profile distortion relative to a Gaussian distribution. The RSS escalated to 7.8, in contrast to 0.7 of the pump light at a pump pulse repetition rate of 500 Hz. By suppressing thermal convection using a high-viscosity medium, we effectively mitigated beam distortion. The RSS was reduced to 0.7 at a pump pulse repetition rate of 500 Hz, coinciding with a twentyfold increase in viscosity, thereby enhancing the beam quality. By integrating hydrodynamic analysis, we elucidated and mitigated distortion with targeted solutions. Our research offers an interdisciplinary perspective on studying thermal effects and contributes to the application of SBS-PCMs in high-repetition-rate laser systems by unveiling the mechanism of photothermal effects.

高功率纳秒级激光二极管高侧驱动电路

纳秒级高功率的激光发射系统对激光雷达的探测性能产生重要影响。本文对普遍使用的激光二极管低侧栅极驱动电路进行修改得到高侧栅极驱动方式,使之能够适用于共阴极激光发射电路。该高侧驱动方式采用了一个半桥驱动器,两个GaN FET作为核心器件来控制激光二极管的发光。文中分析了该拓扑结构中电压、电容、电阻、电感等因素对流经激光器电流波形的影响。经过实验测试,在高重复频率下该电路能够产生3.1 ns脉冲宽度,约65 W的峰值功率,能够作为激光雷达的发射模块对场景进行扫描成像。

HT-6M托卡马克加热场脉冲电源的设计

HT-6M托卡马克装置重建是为响应“一带一路”倡议的中泰合作国际项目,加热场脉冲电源的作用是击穿和产生等离子体,其电源方案采用电容储能脉冲放电形式。为计算出满足要求的电源参数,对加热场脉冲电源放电过程进行数学分析,并根据电源设备的工作参数,设计并研制了电源的核心器件。为验证电源放电过程的理论分析,研制了一套小型电容储能脉冲电源,证明理论分析正确性的同时,对电源大功率固态断路器进行关断实验。

一种小型化脉冲行波管高压电源设计与实现

为满足雷达整机对发射机小型化的需求,针对8~18 GHz宽带脉冲行波管设计了一种小型化高压电源。采用脉冲峰值功率设计方法,结合高压电容储能,实现了行波管在脉冲工作期间高压稳定输出。同时主功率逆变电路采用了移相全桥拓扑结构,高压整流电路采用了碳化硅二极管,这可减轻电源的散热压力,提高高压电源的功率密度。研制的小型化脉冲高压电源,阴极电压-6.5 kV,最大工作脉宽2 ms,峰值功率最大1600 W。与某型号脉冲行波管联调,在脉冲工作期间行波管输出射频信号功率稳定,测试结果验证了该设计方法的可行性。

基于Marx电路的固态高压脉冲电源设计

针对高压脉冲放电和低温等离子体应用的要求,设计了一种基于Marx电路的高重复频率的固态高压脉冲发生装置。该脉冲电源利用Marx电路电容并联充电、串联放电的原理,选取绝缘栅双极型晶体管(IGBT)作为放电开关,控制电路的模态切换。Marx主电路由84级单元组成,每级单元包含IGBT开关管、快恢复二极管和储能电容。实验结果表明,在输入电压为480 V直流电压,并且在300 Hz的频率下,该电源可以产生幅值为20 kV、脉宽为500 ns的高压脉冲,满足设计要求。

大功率高能脉冲激光电源设计

根据YAG激光器对大功率高能量脉冲电源的应用需求,设计了一种大功率脉冲激光电源,可实现高脉冲能量重复频率输出及充电电压灵活调控。前级充电网络采用串联LC谐振变换器,后级脉冲形成网络选择晶闸管触发LC放电电路。最终,研制了1台7 kW实验样机,最大重复频率10 Hz,最高充电电压2.2 kV,可实现单脉冲最高700 J电能输出,满足大功率高能脉冲输出的应用需求,实验测试结果验证了设计的可行性。

一种X波段机载MPM设计与工程实现

微波功率模块(MPM)是高集成度的一种微波发射机,它是真空放大器件应用的重大变革,涉及微波、真空电子、集成电源、微系统集成等多技术领域,具备单机功率大、频带宽、效率高、功率密度高、可靠性高等优点,可用于无人机电子对抗系统、有源相控阵、拖曳式高功率电子干扰诱饵、气象雷达等许多领域。文中介绍了一种X波段中功率机载MPM的设计方法,详细阐述了励磁电感、谐振电感、谐振电容三元素串联谐振全桥拓扑高压电源、载频脉冲调制器、模块结构与热设计及其关键技术,并给出了实测数据,以期给相关从业人员带来一些启发和帮助。该项目研制的MPM已在外场成功完成空空、空地试验应用,性能非常好,可推广使用。

基于半桥结构的双极性脉冲电源的研究

为了满足脉冲电场消融的应用需求,解决单极性脉冲电场分布不均匀的问题,研制了一台基于半桥结构的主电路、具有纳秒级前沿的高重复频率双极性亚微秒高压脉冲电源。该脉冲电源由FPGA提供控制信号,经过驱动芯片放大控制信号后,利用光耦隔离驱动多个SiC MOSFET。驱动电路所需元器件较少,信号控制时序简单,可提供负压偏置,使开关管可靠关断,提高了电路的抗电磁干扰能力,使电源能稳定运行。通过电阻负载实验,对比分析了不同栅极电阻对驱动电压的影响,驱动电压上升沿时间越短对应的双极性高压脉冲前沿越快。实验结果表明:所设计的高频双极性脉冲电源在100Ω纯阻性负载上能够稳定产生重复频率双极性纳秒脉冲,输出电压0~±4 kV可调,脉宽0.2~1.0μs可调,正负脉冲相间延时0~1 ms可调,上升沿和下降沿60~150 ns之间。该双极性脉冲电源电路设计结构紧凑,能满足应用的参数需求。

带反偏置的双路高压脉冲电源的研究

通过调节反向偏置电压可以改善电场渗透对质谱仪的影响,提高质谱仪的分辨率。为了满足质谱仪对脉冲电场的不同要求,提出了一种可以同时输出两路极性相反脉冲电场的脉冲电源,且高压正脉冲叠加幅值可调的直流负偏置电压。该电源只需一个充电源便可以产生正负两路脉冲电场。分析了串联开关同步驱动效果,随后通过增加补偿绕组和并联电阻优化了串联电容的分压不均的问题,并验证一个磁芯加多个副边绕组的方案可进一步降低充电电压不均。最终实现了4个电容器的充电电压与平均电压相差不超过0.1%。搭建了一台4级的电源样机,实验表明,其可以在容性负载上产生一路幅值为0~1.5 kV、脉宽为2~10μs可调的高压正脉冲且叠加幅值为0~-200 V的反向偏置电压,和一路幅值为0~-1.5 kV、脉宽为2~10μs可调的高压负脉冲,频率高达10 kHz,正负脉冲的前沿均小于30 ns,脉冲波形平稳。该脉冲电源结构紧凑,并且输出电压、脉宽、频率均连续可调。

开关型脉冲激光电源系统的设计与实现

本文探究了开关型脉冲激光电源系统的设计方案,并通过MTALAB仿真验证其功能的实现情况。根据脉冲氙灯的特性以及脉冲激光电源的工作原理,设计了基于串联谐振型半桥变换器的电能变换主电路,保证电源电压噪声小、稳定性好;同时,使用高频高压变压器降低电磁干扰、提高转换效率。在完成系统设计后,使用MATLAB仿真软件构建系统模型并验证其功能。结果表明,该系统的软启动功能、自保护功能以及缓上电功能可以正常实现,符合设计预期。

The pulsed microwave damage trend of a bipolar transistor as a function of pulse parameters

In the present paper we conduct a theoretical study of the thermal accumulation effect of a typical bipolar transistor caused by high power pulsed microwaves（HPMs）,and investigate the thermal accumulation effect as a function of pulse repetition frequency（PRF） and duty cycle.A study of the damage mechanism of the device is carried out from the variation analysis of the distribution of the electric field and the current density.The result shows that the accumulation temperature increases with PRF increasing and the threshold for the transistor is about 2 kHz.The response of the peak temperature induced by the injected single pulses indicates that the falling time is much longer than the rising time.Adopting the fitting method,the relationship between the peak temperature and the time during the rising edge and that between the peak temperature and the time during the falling edge are obtained.Moreover,the accumulation temperature decreases with duty cycle increasing for a certain mean power.

直流叠加高压脉冲的真空灭弧室老炼技术

提高真空灭弧室的老炼均匀度,并有效调控老炼电弧作用区域的能量注入方式和程度,是真空灭弧室老炼技术所要解决的两个核心问题。然而,在单一电源模式下,真空灭弧室触头间隙的击穿条件和放电能量相互制约,其老炼的时间和空间约束条件难以独立调节,所以难以同时满足对老炼均匀度和作用区域能量调控两方面的要求。为此提出了一种直流叠加高压脉冲的真空灭弧室双电源老炼技术方案,通过小能量的高压脉冲实现对触头间隙绝缘弱点的击穿和精确定位,引入大电流对该弱点区域进行老炼处理。与传统老炼方式的实验结果对比表明:该老炼方法可显著提升灭弧室雷电冲击耐压水平,提升幅度在40%左右,为真空灭弧室老炼技术的进一步发展提供了新的思路。

基于高功率脉冲技术的微深孔溅射关键工艺研究

根据高功率脉冲电源在溅射时能提升离化率,增加离子浓度的特点,研究了高功率脉冲电源的峰值电流、频率、脉宽与离化效果之间的关系,并比对了溅射效果,分析了高功率脉冲与偏压电源之间的作用关系。通过这些关键工艺的研究,成功实现了深径比10∶1的微孔溅射金属化并进行工程应用,为三维集成高深径比微孔金属化提供了一种低成本的解决方案。

无载波高重频电磁脉冲对电子侦察设备干扰机理分析

电子侦察设备具有极高的信息获取能力,特别是战场感知能力,被广泛应用在军事领域。为提高被侦察装备侦测的目标的生存概率,研究简单、快速、隐蔽性好、高效的电子干扰方法,进而使我方被侦测目标(直升机、运输机、歼击机、无人机、舰艇等)在战场复杂电磁环境中获得有效保护,具有重要意义。高功率、高重频电磁脉冲干扰作为一种新型电子干扰方式,具有一机多用、反应快速、干扰机理先进等优势,与传统的电子干扰方式相比各有优势与特点,可彼此相结合,技术互补,提高电子干扰能力,增强我方被侦测目标的战场生存力。通过数值建模仿真,对电磁脉冲对电子侦察设备的干扰机理进行分析。

无载波高重频电磁脉冲对电子侦察设备干扰机理分析

电子侦察设备具有极高的信息获取能力,特别是战场感知能力,被广泛应用在各种领域。为提高被侦察装备侦测的目标的生存概率,研究简单、快速、隐蔽性好、高效的电子千扰方法,进而使我方被侦测目标(直升机、运输机、歼击机、无人机、舰艇等)在战场复杂电磁环境中获得有效保护,具有重要意义。高功率、高重频电磁脉冲干扰作为一种新型电子干扰方式,具有一机多用、反应快速、干扰机理先进等优势,与传统的电子干扰方式相比各有自身的优势与特点,可彼此相结合,技术互补,提高电子干扰能力,增强我方被侦测目标战场生存力。通过数值建模仿真,对电磁脉冲对电子侦察设备的干扰机理进行分析。

基于部分功率调控的有源–无源电容分裂叠加式高峰均比低频脉冲功率平抑方法

高峰均比低频脉冲电流载荷影响航天器电源系统高效稳定运行,基于大容量储能电容阵的脉冲功率被动平抑技术极大增加航天器系统的体积重量。以降低航天器电源系统体积重量为目标,提出基于部分功率调控的脉冲功率平抑方法。通过将无源解耦电容分裂为有源电容与无源解耦电容串联,不仅为负载提供稳定的供电电压,而且大幅增加解耦电容电压波动范围、减小解耦电容体积重量。由于有源电容仅需提供部分脉冲负载功率,有效降低了脉冲功率主动平抑所需额外增加的功率电路容量、体积重量和损耗。文中详细分析所提脉冲平抑系统架构、电路实现及其控制方法,实验结果证明了所提方法的可行性和有效性。