【作者】 张瑜；

【导师】 刘金亮；

【作者基本信息】 国防科学技术大学 ， 物理电子学， 2009， 硕士

【摘要】 脉冲功率技术在国防、工业以及自然科学研究等领域得到了广泛应用,高峰值功率、高重复频率和小型化是脉冲功率系统发展的主要方向。近年来,实用型紧凑化高压纳秒脉冲发生器在国内外得到了广泛的关注。本论文通过对闭合磁环脉冲变压器、卷绕式平板脉冲形成线、高功率负载和纳秒脉冲检测器等关键部件进行理论分析、工程设计和实验研究,成功地研制了一台结构紧凑的高压纳秒脉冲发生器。这些工作对小型紧凑化高压脉冲发生器的研究具有重要指导意义。论文研究的主要内容包括以下四个方面:1.研制了一台闭合磁环高压脉冲变压器。1)提出了实现闭合磁芯式脉冲变压器高电压、高变比输出的设计方法,建立了理论计算模型,给出了变压器重要参数的计算公式,该变压器有效耦合系数为0.945。2)对变压器的磁芯饱和和磁芯损耗进行了初步分析。3)对变压器的时域和频域响应特性进行了系统的分析,建立了理论计算模型,通过电路软件模拟和实验证明:减小变压器绕组漏电感和分布电容可改善高频响应能力,陡化输出电压脉冲的前沿和后沿;增大磁化电感可明显改善低频响应能力以及增加脉冲平顶的稳定度。该变压器能较好地响应脉宽为5μs ~100μs的方波脉冲信号和频带为1 Hz ~1 MHz的重频信号。4)利用变压器对0.32 nF电容器进行充电实验,充电电压高达230 kV,升压倍数为109,验证了理论计算和分析的正确性。2.研制了卷绕式平板脉冲形成线。建立了关于卷绕式平板脉冲形成线的理论分析模型,对各电磁参数进行了理论计算。利用电磁场分析软件对脉冲形成线进行静电场模拟,并结合充电实验研究了形成线的耐压性能。研制的平板脉冲形成线波阻抗为3.5Ω,输出脉宽为10 ns,能承受的最高脉冲电压大于200 kV。3.高功率水电阻负载及纳秒脉冲检测器的研制。1)建立了水电阻负载的寄生参数理论分析模型,从理论计算、软件模拟和实验三个方面分析了寄生参数对负载波形的影响。2)通过改进低压臂电阻,研制了能够准确响应高压短脉冲信号的电阻分压器;建立了Rogowski线圈的分布参数理论分析模型,具体分析了线圈各分布参数、取样电阻的寄生参数以及阻尼电阻对线圈测量波形的影响,通过采用较大功率的无感电阻,成功地研制了脉冲前沿响应时间均小于2.5 ns的磁芯式和非磁芯式两种Rogowski线圈。4)研制出一台紧凑型高压纳秒脉冲发生器。该发生器主要由闭合磁环式脉冲变压器、卷绕式平板脉冲形成线、火花开关及负载组成,结构紧凑,其直径为0.22 m、长度为0.8 m、重量为30 kg。在负载匹配情形下(3.5Ω),该脉冲发生器最高输出脉冲电压为84 kV,半高全宽为9 ns,上升沿为5.1 ns;负载阻抗为50Ω时,输出波形为一锯齿波,最高输出电压为165 kV,半高全宽为68 ns,上升沿6.5 ns。目前,该高电压纳秒脉冲发生器已用于触发本实验室的高功率气体开关。更多还原

【Abstract】 Pulsed power technology has been widely used in the fields of national defence, industry and scientific research. Development tendencies of pulsed power systems mainly include high power, high repetitive frequency and compactness. In recent years, more practical high-voltage nanosecond pulse generator with compact structure has been widely concerned by researchers in the world. A compact high-voltage nanosecond pulse generator, which consists of pulse transformer with closed magnetic core, curled parallel strip pulse forming line (CPSPFL), spark gap and powerful load resistor, is developed in this paper. Nanosecond pulse detectors are also designed. Theoretical analyses, engineering design and experiments have been carried out to study all the important parts of the pulse generator. This work is of great importance to researches on compact high-voltage pulse generator. The detailed contents are as follows.1. A small high-voltage pulse transformer with closed magnetic core is developed.1) Method of high-voltage outputs and high step-up ratio of pulse transformer with closed magnetic core is put forward. Theoretical calculations of important parameters of pulse transformer are also presented in detail. The effective coupling coefficient of transformer is 0.945. 2) Saturation and the loss of magnetic core have been analyzed. 3) Responsive characteristics of time-domain and frequency-domain of pulse transformer have been studied and theoretical calculations have been done. Results of circuital simulation and experiments show that when leakage inductances and distributed capacitances of transformer windings decrease, characteristics of high-frequency response of transformer can be improved, and the front edge and back edge of output voltage pulse of transformer can also be cut down. When magnetization inductance of transformer increases, characteristics of low-frequency response of transformer can be improved and the flat top of output voltage pulse of transformer becomes more stable. The pulse transformer can excellently respond to square pulse with pulse width ranging from 5μs to100μs and its responsive frequency band ranges from 1 Hz to 1 MHz. 4) The pulse transformer was used to charge a load capacitance of 0.32 nF and results of experiment showed that the amplitude of output voltage of transformer reached as high as 230 kV and step-up ratio is 1: 109. These results backed up theoretical calculations.2. A curled parallel strip pulse forming line (CPSPFL) is developed.Theoretical analyses of CPSPFL and calculations of important parameters are presented. Distribution of electric fields and potentials of CPSPFL is analyzed by electromagnetic software. Characteristics of high-voltage endurance of CPSPFL are also studied. The CPSPFL with impedance of 3.5Ωproduced short pulse of 10 ns and it was able to resist high voltage pulse with amplitude of 200 kV.3. Design of the powerful load resistor and nanosecond pulse detectors. 1) Parasitic parameters of load resistor have been analyzed. By theoretical calculations, circuital simulation and experiment, the impacts of parasitic parameters on output waveform of load resistor have also been studied. 2) Resistant divider which detects high-voltage short pulses is developed due to the improvement of its low-voltage resistor. Theoretical analyses of distributed parameters of Rogowski coil are presented. Damped resistor, distributed parameters of Rogowski coil and parasitic parameters of sampling resistor have great impacts on output signal of Rogowski coil and these impacts are analyzed in detail. By using high-power resistor with little parasitic inductance, fast responsive Rogowski coils with magnetic core and non-magnetic core have been developed, and their responsive time to front edge of pulse are both less than 2.5 ns.4. The compact high-voltage nanosecond pulse generator is developed.The compact pulse generator consists of pulse transformer with closed magnetic core, CPSPFL, spark gap and load resistor. The diameter of the generator is 0.22 m, the length is 0.8 m and the weight is about 30 kg. To the matched load (3.5Ω), the pulse generator generated high-voltage short pulse with amplitude of 84 kV, full width at half maximum (FWHM) of 9 ns and rise time of 5.1 ns. To a load of 50Ω, the generator generated saw-tooth pulse with amplitude of 165 kV, FWHM of 68 ns and rise time of 6.5 ns. At present, the high-voltage nanosecond pulse generator has been used to trigger the trigatron and field-distortion switch in our laboratory.更多还原