【作者】 王松松；

【导师】 舒挺； 杨汉武；

【作者基本信息】 国防科学技术大学 ， 电子科学与技术， 2013， 博士

【摘要】 国防和民用需求对脉冲功率系统提出了紧凑化、固态化的发展要求。层叠Blumlein线集能量储存、脉冲形成和电压增益等功能于一身，陶瓷介质具有储能密度高、介电常数稳定和环境适应能力强等优点，故陶瓷储能层叠Blumlein线是实现脉冲功率系统紧凑化、固态化发展的重要技术途径。本论文系统分析了层叠Blumlein线的相关理论，优化设计了陶瓷储能层叠Blumlein线的结构尺寸，实验研究了陶瓷储能介质的击穿特性和多路开关同步触发技术，并研制出一台3级陶瓷储能层叠Blumlein线实验装置。主要工作如下：1.从脉冲形成波过程和杂散阻抗影响等两方面对层叠Blumlein线进行了系统地理论分析。在波过程分析中计算出了层叠Blumlein线各节点处的入射和反射系数表达式，并采用Laplace方法求解了层叠Blumlein线产生脉冲的解析表达式。建立了分析杂散阻抗影响的电路模型，计算结果表明，要保证电压增益与级数基本相等，应尽可能降低Blumlein线阻抗与杂散阻抗的比值。2.为将结构与电路参数相结合，采用矩量法编程求解了平板型层叠Blumlein线的各特征参量，并利用CST Microwave Studio建立层叠Blumlein线3维电磁仿真模型，研究了各结构参数对脉冲波形的影响。研究结果表明：耦合阻抗与相邻电极板间阻抗并联降低了层叠Blumlein线匹配阻抗；介质板厚与电极板宽之比越小，越有利于提高电压增益和能量效率；较高的长宽比结构有利于近平面波在平板Blumlein线中的形成与传输，从而有利于匹配负载上获得近方波脉冲；平板型层叠Blumlein线介质宽度应大于电极板宽度，以缓解介质边缘处电场增强；仅增加介质板厚度，脉宽保持稳定，但方波特性变差，前后沿被逐渐拉长，且平顶出现振荡。3.分析了储能介质不连续性对平板型脉冲形成线的影响，研究结果表明其影响主要为两方面：其一是介质内部缝隙造成平板线内部电场分布不均匀，降低介质击穿场强，且截面呈锐角的缝隙危害最大；其二是介电常数差异会降低层叠Blumlein线输出脉冲平顶质量，应尽量使各单元的电长度基本相等。4.建立了研究储能陶瓷介质击穿特性的实验系统，实验研究了电极形状、外部介质、充电波形和重复频率等因素对介质击穿场强的影响。研究结果表明：在甘油介质中利用半球型电极对陶瓷介质μs级脉冲充电测得其击穿场强26kV/mm，为所有测试情况中的最大值；真空环境下直流电压比脉冲电压所测得的表面闪络击穿场强略高；高重复频率脉冲测试条件下的陶瓷介质内部存在严重热积累，导致在介质内部快速形成击穿通道，从而降低介质击穿强度。5.基于小尺寸（95×95×4mm3）陶瓷介质板，设计了一台3级陶瓷储能层叠Blumlein线实验装置，模拟了其在不同环境中所产生的脉冲波形，结果表明：该结构装置适宜工作在变压器油和真空等介电常数较低的环境。分析了开关对该结构装置性能的影响，结果表明各开关抖动会导致脉冲前后沿呈现阶梯状，同时降低陶瓷介质的耐压能力。6.研制了一台传输线脉冲变压器，实验证明其可将单路ns级脉冲分离为3路参数（幅值20kV、脉宽12ns、上升时间5ns）基本一致的子脉冲。利用此3路子脉冲在实验中实现了3路开关的ns级同步触发。7.建立并测试了一台3级陶瓷储能层叠Blumlein线实验装置，实验中对该装置直流充电至4kV，3路开关经同步触发导通，在10匹配负载上获得了幅值约11.4kV、脉宽约32ns、上升时间约为5ns的脉冲输出，其电压增益约为2.9，能量效率约为90%。分别测试了不同因素对装置工作性能的影响，结果表明：多路同步触发脉冲可有效改善多开关导通同步性能；ns级脉冲充电条件下在匹配负载上得到的脉冲电压增益约为2.7，能量效率约为79%；测试了不同介质环境对装置输出结果的影响，结果证明此类装置适合工作于低介电常数的介质环境中。更多还原

【Abstract】 National defense and civil applications require the pulsed power system (PPS) withfeatures of compactness and solid-state. The structure of stacked Blumlein line (SBL) isbeneficial to the compact PPS due to its combination of energy storage, pulse formingand voltage multiplication. Ceramic for energy storage has wide potential for PPSapplications due to its essential characters such as high energy storage density, stabledielectric constant and excellent environmental adaptability. Therefore, SBL usingceramic for energy storage is an important technology approach to achieving compactand solid PPS. Five significant issues, i.e., the correlated theory of the SBL, thestructure optimization of the SBL; the breakdown characteristics of the ceramic,multi-switch triggered in synchronization, and the facility of a3-stage SBL usingceramic for energy storage, are studied and analyzed systematically in this dissertation.The main content involved is depicted as following.1. The correlated theory of the SBL is studied systematically through the analysisof its pulse forming process (PFP) and parasitic impedance. In the PFP analysis, thetransmission and reflection coefficients in each junction point of SBL are calculated,and the analytical expression of the output pulse for a lossless SBL is obtained by usingLaplace transform. A circuit model is developed for analyzing the influence of theparasitic impedance. The calculation results indicate that the voltage multiplication isbasically equal to the stage number as the ratio of the Blumlein impedance to theparasitic one decreases.2. For combining the SBL structure with its circuit parameters, the characteristicparameters of a parallel-plate SBL are calculated through the coding in Method ofMoment (MoM), and the effects of structural parameters on the output pulse are studiedthrough a3D SBL model developed in CST Microwave Studio. The results indicate:1)coupling impedances in parallel connection with the impedances formed betweenadjacent electrodes decrease the SBL matching impedance;2) the smaller ratio ofdielectric thickness to electrode width, the more benefit to improving the voltagemultiplication and the energy efficiency;3) the structure with a high ratio of length towidth is advantageous to a plane wave forming and transmission in a parallel plateBlumlein, so as to producing a rectangular pulse with good quality across a matchingload;4) it is beneficial to alleviating the electric-field enhancement located the electrodeedges in a parallel-plate SBL when the dielectric is wider than the electrode;5) as onlyincreasing the dielectric thickness, the output pulse duration is kept unchanged, but thepulse front and tail edges are stretched severely, and some oscillation emerges in thepulse flat-top.3. The influence of the ceramic dielectric discontinuity on the ceramic SBL is analyzed. The results indicate two aspects of this influence:1) the internal gap of theceramic is likely to result in the decrease of the ceramic breakdown strength (BDS) dueto the non-uniform distribution of electric field inside the parallel SBL, and the mostjeopardous gap is the one with a shape of triangle cross-view;2) the permittivitydifference of ceramic slabs deteriorates the output pulse flat-top quality of the ceramicSBL, and the best case is that each Blumlein has the same electric length by adjustingthe location of different ceramic slabs.4. Experimental system is built for testing the breakdown characteristics of theceramic. Four influence factors of the ceramic BDS, such as electrode configuration,dielectric surroundings, charging source and repetitive rates, are studied and analyzed.The results indicate:1) the maximum ceramic BDS among all the tests is26.01kV/mmunder conditions of semi-sphere electrode, glycerin surroundings, and single μs pulse;2)the vacuum flashover BDS tested under dc charging condition is slightly higher than theone under pulsed condition;3) the condition of pulse charging in high repetition rate cancause the thermal accumulation inside the ceramic, then ceramic melted, and fastformation of breakdown channel, thereby reducing the ceramic BDS.5. A SBL using ceramic for energy storage is proposed based on the small ceramicslab with dimensions of95×95×4mm3, and the output pulse waveforms are simulatedin different dielectric surroundings. The results indicate that this structural facility isappropriate to work in the surroundings with low permittivity, such as transformer oil orvacuum. The performance of the facility affected by switch working behavior isanalyzed. The results indicate that the dispersity of closure time of multi-switch resultsin ladder distortions within the front and tail edges of the output pulse, meanwhiledecreasing the ceramic BDS.6. A transmission line pulse transformer (TLT) is developed, and the testing resultsdemonstrate that the TLT is capable of splitting a narrow pulse into3subpulses with thesame parameters, i.e.,20kV voltage amplitude,12ns pulse width, and5ns rise time.By using the3subpulses, we have achieved3switches synchronizedly triggered in thens range.7. The facility of a3-stage SBL using ceramic for energy storage is developed andtested. After the3-stage SBL is dc charged up to4kV, a32ns quasi-rectangular pulseof11.4kV is measured across a10dummy load under the condition of the3switchestriggered in synchronization. The voltage multiplication is about2.9, and the energyefficiency is about90%. The effects of three factors, i.e., switching condition, chargingsource, and working surroundings, on the facility performance are experimentallystudied. The results indicate:1) multiple synchronized pulses can effectively improvethe closure time synchronicity of the multi-switch;2) the pulse with voltagemultiplication of2.7and energy efficiency of79%is achieved across the matched loadunder ns pulse charging condition;3) the effect of different working surroundings on the performance of the facility is tested, and the results demonstrate that the facility isappropriate to be operating in the surroundings with low dielectric constant.更多还原