超高速大电流半导体开关实验研究

 利用自行研制的固态半导体开关RSD,采用电容储能方式,研究了RSD的电压响应时间、大电流特性、电流上升率等。在测试RSD的电压响应时间时,得到了25 ns的电压下降曲线。在主电容电压为8 kV时,得到峰值为10.1 kA、脉宽为34 μs、电流上升率为2.03 kA/μs的大电流脉冲。通过调整主电路,在主电容为3 kV时,得到的电流脉冲峰值为8.5 kA、脉宽为2.5 μs、电流上升率为7.2 kA/μs。结果表明,RSD是一种开通快、通流能力强、电流上升率高的大功率半导体开关器件。     

超高速大电流半导体开关实验研究

利用自行研制的固态半导体开关RSD,采用电容储能方式,研究了RSD的电压响应时间、大电流特性、电流上升率等。在测试RSD的电压响应时间时,得到了25 ns的电压下降曲线。在主电容电压为8 kV时,得到峰值为10.1 kA、脉宽为34 μs、电流上升率为2.03 kA/μs的大电流脉冲。通过调整主电路,在主电容为3 kV时,得到的电流脉冲峰值为8.5 kA、脉宽为2.5 μs、电流上升率为7.2 kA/μs。结果表明,RSD是一种开通快、通流能力强、电流上升率高的大功率半导体开关器件。     

Nanosecond pulsed power generator for a voltage amplitude up to 300 kV and a repetition rate up to 16 Hz for fine disintegration of quartz

A generator of high-power high-voltage nanosecond pulses is intended for electrical discharge disintegration of mineral quartz and other nonconducting minerals. It includes a 320 kV Marx pulsed voltage generator, a high-voltage glycerin-insulated coaxial peaking capacitor, and an output gas spark switch followed by a load, an electric discharge disintegration chamber. The main parameters of the generator are as follows: a voltage pulse amplitude of up to 300 kV, an output impedance of ≈10 Ω, a discharge current amplitude of up to 25 kA for a half-period of 80–90 ns, and a pulse repetition rate of up to 16 Hz.     

Pseudospark switches-technological aspects and application

We report results of the development of fast closing switches, so-called pseudospark switches, at Erlangen University. Two different parameter regimes are under investigation: medium power switches (32 kV anode voltage, 30 kA anode current and 0.02 C charge transfer per shot) for pulsed gas discharge lasers and high power switches (30 kV anode voltage, 400 kA anode current and 3.4 C charge transfer per shot) for high current applications. The lifetime of these switches is determined by erosion of the cathode. The total charge transfer of devices with one discharge channel is about 220 kC for the medium and 27 kC for the high power switch. At currents exceeding 45 kA a sudden increase in erosion rate was observed. Multichannel devices are suited to increase lifetime as the current per channel can be reduced. Successful experiments with radial and coaxial arrangements of the discharge channels were performed. In these systems the discharge channels move due to magnetic forces. A skilful use of this phenomena will result in a considerably increase of switch lifetime. Multigap devices enable an increase of anode voltage. A three gap switch has run reliably at an anode voltage of 70 kV     

Controlled discharge in a vacuum gap switched by 1 Mc current pulses of up to 150 kA

The firing delay time, the rise time of the current up to its maximum, and the primary current amplitude of a controlled discharge in a vacuum gap are considered, for a voltage range of 10–80 kV, with a residual gas pressure in the chamber of 10^–4–10^–5 mm of mercury. The gap is switched by a damped oscillatory current pulse with a frequency of 1.25 Mc and a maximum amplitude of about 150 kA. The discharge is started by either one or three triggering devices.     

Photoconductive semiconductor switches

Optically activated GaAs switches operated in their high-gain mode are being used or tested for pulsed power applications as diverse as low-impedance, high-current firing sets in munitions; high impedance, low-current Pockels cell or Q-switch drivers for lasers; high-voltage drivers for laser diode arrays; high-voltage, high-current, compact accelerators; and pulsers for ground penetrating radar. This paper will describe the properties of high-gain photoconductive semiconductor switches (PCSS), and how they are used in a variety of pulsed power applications. For firing sets, we have switched up to 7 kA in a very compact package. For driving Q switches, the load is the small (30 pF) capacitance of the Q switch which is charged to 6 kV. We have demonstrated that we can modulate a laser beam with a subnanosecond rise time. Using PCSS, we have demonstrated gain switching a series-connected laser diode array, obtaining an optical output with a peak power of 50 kW and a pulse duration of 100 ps. For accelerators, we are using PCSS to switch a 260 kV, 60 kA Blumlein. A pulser suitable for use in ground-penetrating radar has been demonstrated at 100 kV, 1.3 kA. This paper will describe the specific project requirements and switch parameters in all of these applications, and emphasize the switch research and development that is being pursued to address the important issues     

Capillary discharge soft X-ray laslng in Ne-like Ar pumped by long current pulses

A capillary discharge soft X-ray laser operating at 46.9 nm on the transition 3p-3s (J = 0-1) of the Ne-like Ar has been realized by exciting the active medium with a long half-cycle duration current pulse of 140 ns. The current is produced by discharging a 10 nF water dielectric capacitor, initially charged to voltages lower than 200 kV by a six stage Marx generator, through a 15-cm long capillary channels. The laser amplification has been obtained by properly adjusting all the other experimental parameters. Utilizing a 3-mm in diameter Al₂O₃ capillary channel initially filled with 0.3 torr of Ar pressure, a laser beam, which has a 4-mrad divergence and a time duration of 1.3 ns, is characterized by a gain of 0.6±0.1 cm^-1. The stability of the plasma compression followed by the laser emission is verified. Received 13 December 2001     

用于等离子体焦点装置的强流装置

研制了用于稠密等离子体焦点的强流装置,该装置采用八台低电感低内阻脉冲电容器和八个低感大电流、可控触发高压开关并联组成初级储能模块,高压开关同步击穿后产生μs级强电流经平行板传输线加载到负载。脉冲电容器和高压开关采用一体化设计,结构紧凑,使脉冲电容器与高压开关间的连接电感尽可能小;平板传输线为扇形结构,一个扇形平板传输线连接一个高压开关,平行板传输线可以将电感做得较小,有利于大电流回路的传输。在脉冲电容器充电20 kV时,假负载上可以得到500 kA的电流,电流上升时间约为3.7 μs。     

12kV高压反向触发双极晶闸管开关组件

介绍了反向触发双极晶闸管(RSD)开关的结构和触发工作原理,分析了RSD组件设计要求,利用两级触发原理研制了12 kV高压RSD组件及其触发系统,工作电压10～12 kV。试验结果表明:该高压RSD串联组件触发稳定,工作可靠,12 kV工作电压下峰值电流可达133 kA,传输电荷24 C,电流变化率可达4.12 kA/μs,导通的峰值功率可达1.6 GW。     

12 kV高压反向触发双极晶闸管开关组件

介绍了反向触发双极晶闸管(RSD)开关的结构和触发工作原理,分析了RSD组件设计要求,利用两级触发原理研制了12 kV高压RSD组件及其触发系统,工作电压10~12 kV。试验结果表明：该高压RSD 串联组件触发稳定,工作可靠,12 kV工作电压下峰值电流可达133 kA,传输电荷24 C,电流变化率可达4.12 kA/μs,导通的峰值功率可达1.6 GW。     

200 kV全固态Marx结构方波脉冲电源设计

采用功率IGBT串联组合模块作为放电开关,设计了16级Marx结构的脉冲电源,能够产生可调高压方波脉冲。由9支耐压3 kV的IGBT串联组成最大工作电压12.5 kV的串联组合模块;通过磁隔离触发方式控制各级IGBT的同步导通和关断。输出电压从几kV至200 kV可调、输出脉宽随外部触发信号宽度在1.5~10 s范围内可调、前沿小于500 ns、后沿小于2.3 s;在输出电压大于100 kV、输出电流20 A时顶降小于2%。     

200 kV全固态Marx结构方波脉冲电源设计

采用功率IGBT串联组合模块作为放电开关,设计了16级Marx结构的脉冲电源,能够产生可调高压方波脉冲。由9支耐压3 kV的IGBT串联组成最大工作电压12.5 kV的串联组合模块;通过磁隔离触发方式控制各级IGBT的同步导通和关断。输出电压从几kV至200 kV可调、输出脉宽随外部触发信号宽度在1.5~10 s范围内可调、前沿小于500 ns、后沿小于2.3 s;在输出电压大于100 kV、输出电流20 A时顶降小于2%。     

爆磁压缩装置经组合功率调节系统产生高电压的实验研究

介绍了以爆磁压缩装置为脉冲功率能源,经变压器和爆炸金属丝断路开关组合功率调节系统,在电阻负载上产生高电压的实验研究。实验结果为：在100W 水电阻负载两端得到了约800kV的高电压脉冲,脉宽约100ns。此项工作拓宽了爆磁压缩装置的应用范围。     

晶闸管串联开关及同步触发系统研制

为满足脉冲功率源对高电压、大电流开关的需求,利用传统晶闸管均压技术,将多个晶闸管串联,研制出额定电压10 kV,额定电流500 A的晶闸管串联开关。根据晶闸管的触发原理,设计出同步触发多个晶闸管的触发系统。该触发系统采用绝缘栅双极型晶体管开关对直流电压阻断产生脉宽可调的低压脉冲,经多个隔离脉冲变压器升压,产生多路同步触发信号。对晶闸管触发系统及晶闸管串联开关进行了测试,测试结果表明：晶闸管触发系统可输出20 V,1 A的多路同步触发信号,触发信号的脉宽30~60 s可调,重复频率100 Hz;晶闸管串联开关每路静态均压和动态均压波动小,在高电压条件下能稳定工作。     

直线变压器驱动源模块输出电流上升时间调节

针对磁驱动等熵压缩实验对加载电流波形的特殊需求,基于改造后的1MA直线变压器驱动源(LTD)原理性模块,开展了输出电流上升时间调节实验研究。48只开关分为4组,由4根高压电缆引入触发脉冲分别触发,共进行了三组不同电缆长度组合的触发放电实验。结果表明:在±32kV充电电压下,输出电流上升时间(0~100%)可由301.2ns增加至436.0ns,相应的输出电流幅度由294.0kA下降至210.2kA。实验还采用光纤探针阵列测试系统同时对其中40只多间隙气体开关的放电发光过程进行了诊断,获得了相应开关的闭合导通起始时间。基于实验参数,利用PSpice电路模型进行了校验,并对早期触发的支路组对后续触发支路组的影响进行了分析。实验初步验证了LTD模块内部子块通过分时放电实现输出波形调节的能力。     

直线变压器驱动源模块输出电流上升时间调节

针对磁驱动等熵压缩实验对加载电流波形的特殊需求, 基于改造后的1 MA直线变压器驱动源（LTD）原理性模块, 开展了输出电流上升时间调节实验研究。48只开关分为4组, 由4根高压电缆引入触发脉冲分别触发, 共进行了三组不同电缆长度组合的触发放电实验。结果表明：在32 kV充电电压下, 输出电流上升时间（0～100%）可由301.2 ns增加至436.0 ns, 相应的输出电流幅度由294.0 kA下降至210.2 kA。实验还采用光纤探针阵列测试系统同时对其中40只多间隙气体开关的放电发光过程进行了诊断, 获得了相应开关的闭合导通起始时间。基于实验参数, 利用PSpice电路模型进行了校验, 并对早期触发的支路组对后续触发支路组的影响进行了分析。实验初步验证了LTD模块内部子块通过分时放电实现输出波形调节的能力。     

一种同轴低电感低抖动多级多通道气体开关

 研制了一种触发电极位于放电通道之外、间隙电极为环状不锈钢弹簧的同轴多级多通道气体开关。该开关通过分布电容耦合实现触发，利用多间隙串联减小抖动，利用弹簧不同匝之间电感隔离形成多通道放电。实验表明：该开关触发可靠、电感低（～20nH）、抖动小（～3ns）、触发特性稳定。     

模块化低阻抗紧凑型Marx发生器

设计的10级低阻抗紧凑型Marx发生器整体体积约0.12 m3,输出功率为30 GW,脉宽200 ns。该发生器采用正负充电,触发开关为三电极场畸变开关,其余开关采用过压自击穿开关;经优化设计,自击穿开关高33 mm、电感13.1 nH,触发开关高42 mm、电感15.2 nH。电容正负电极片与开关电极采用挤压连接,电极片间绝缘材料为聚丙烯薄膜,薄膜共100层,总厚度2 mm,耐受电压大于100 kV;Maxwell模拟表明：此种连接方式可将每个电极连接片电感降低到4.16 nH。Pspice电路模拟和实验均表明：电容器充电100 kV条件下,12 负载上可获得电压高于600 kV、峰值电流大于50 kA的输出。     

高功率反向开关晶体管开关寿命特性

研制了10 kV高压反向开关晶体管（RSD）开关组件。在重复频率0.2 Hz、峰值电流约107 kA、峰值功率约1 GW、单次传输电荷约20 C、单次传输能量约100 kJ条件下,实验次数达50 000多次;主要研究了RSD开关的静态伏安特性随实验次数的变化趋势。采用数值分析的方法,统计拟合得到了长脉冲大电流条件下RSD开关的寿命模型,并依据失效判据初步预估RSD开关的寿命可达107次。     

模块化低阻抗紧凑型Marx发生器

设计的10级低阻抗紧凑型Marx发生器整体体积约0.12 m3,输出功率为30 GW,脉宽200 ns。该发生器采用正负充电,触发开关为三电极场畸变开关,其余开关采用过压自击穿开关;经优化设计,自击穿开关高33 mm、电感13.1 nH,触发开关高42 mm、电感15.2 nH。电容正负电极片与开关电极采用挤压连接,电极片间绝缘材料为聚丙烯薄膜,薄膜共100层,总厚度2 mm,耐受电压大于100 kV;Maxwell模拟表明:此种连接方式可将每个电极连接片电感降低到4.16 nH。Pspice电路模拟和实验均表明:电容器充电100 kV条件下,12 负载上可获得电压高于600 kV、峰值电流大于50 kA的输出。