【作者】 王庆峰；

【导师】 刘庆想；

【作者基本信息】 西南交通大学 ， 电磁场与微波技术， 2011， 博士

【摘要】 重复频率脉冲功率源是脉冲功率技术的重要研究方向之一,具有重要的军用价值和较好的民用前景。紧凑型重复频率脉冲源以高功率微波需求为牵引,是高功率微波的核心技术之一,基于直接驱动技术的脉冲功率源是紧凑型重复频率脉冲源发展的重要技术途径之一,目前得到了广泛的关注。本文在对基于PFN-LTD (Pulse Forming Network-Linear Transformer Driver)技术的脉冲功率源进行详细的理论分析、电路模拟和基础实验研究的基础上,设计并研制了一台10个单元模块感应叠加而成的紧凑型脉冲功率源,并开展了实验研究。本文的设计思想和研究成果对基于PFN-LTD拓扑结构的脉冲功率源的研制具有重要的指导意义,为基于直接驱动技术的脉冲功率源在高功率微波等领域的应用奠定了基础。本论文所作的主要工作包括：介绍了基于直接驱动技术脉冲功率源的技术背景和发展历程,重点阐述了基于PFN-Transformer、PFN-Marx等拓扑结构的直接驱动技术脉冲功率源的关键问题、优缺点以及发展趋势,同时对可实现重复频率运行脉冲功率源的技术途径进行了分析研究,重点对基于水介质螺旋型脉冲形成线拓扑结构的脉冲功率源进行了理论设计及仿真模拟。在此基础上结合高功率微波的需求和LTD采用直接驱动技术的特点,提出了紧凑型重复频率脉冲功率源的新型拓扑结构：PFN-LTD紧凑型重复频率脉冲功率源。基于该拓扑结构设计了一台脉冲功率源,其设计技术参数为输出脉冲电压400～500kV、输出脉冲功率8～10GW、输出脉冲宽度200ns、输出脉冲频率50Hz,这种拓扑结构的脉冲功率源在国内外尚未见到报道。论文围绕基于PFN-LTD技术的紧凑型重复频率脉冲功率源进行较为深入系统的探索研究。为实现上述设计,论文提出并研究了一种基于低感陶瓷电容器的新型脉冲成形技术。首先在探讨基于PFN-LTD技术的脉冲功率源对脉冲成形系统需求的基础上,系统深入得分析了固体介质和液体介质的脉冲形成线以及基于薄膜电容器的脉冲形成网络在输出低阻抗百纳秒高压脉冲时存在的局限性,由此提出了利用高介电常数的低内感陶瓷电容器以及金属板形成的均匀分布电感,研制可用于慢充电的低阻抗脉冲成形系统,理论分析及仿真模拟表明基于该成形技术的脉冲形成网络可获得欧姆量级、百纳秒的中短脉冲,且输出波形质量好。在此基础上设计加工了匹配阻抗2.5欧姆、输出脉冲宽度200ns的Blumlein型脉冲形成网络以及匹配阻抗1欧姆、输出脉冲宽度200ns的单线型脉冲形成网络并开展了实验研究。实验研究结果表明其输出波形质量良好波形前沿可达40ns,为发展基于PFN-LTD技术的紧凑型脉冲功率源奠定了基础。此外,还利用有限元仿真软件对Blumlein型脉冲形成网络的开关端、负载端的电感进行模拟分析及实验研究,在对结果进行分析的基础上提出了开关腔设计的进一步改进方案。分析了高压脉冲通过LTD后输出脉冲前沿的影响因素,探讨了LTD磁芯的性能对输出波形质量的影响。针对铁基纳米晶磁芯具有高饱和磁感应强度,因此在同等伏秒数要求下有利于系统的小型化；同时铁基纳米晶磁芯具有高导磁率和低损耗可以有效提高脉冲功率源能量效率等特点。首次对国内生产的铁基纳米晶磁芯在200ns-300ns范围内的磁化曲线、脉冲导磁率、磁芯有效截面积和平均磁回路长度等参数对能量传递效率的影响,磁芯在热处理过程中与氧气接触在带材表面形成的氧化膜的耐压能力等一系列脉冲磁性能参数开展了研究并得到了大量有意义的数据,实验研究结果为国产的铁基纳米晶磁芯在LTD、感应叠加器、磁开关、脉冲变压器等脉冲功率领域的应用打下了基础。开展了PFN-LTD脉冲功率源的开关选型研究,重点研究TPl10k/50用于PFN-LTD的可行性。论文首先阐述了基于PFN-LTD技术的脉冲功率源对开关的需求,在此基础上以正态分布作为开关延时的数学模型,讨论了多路开关同步工作时,开关抖动、单路输出波形前沿对直线变压器驱动源多路波形叠加的影响。在对国内外可重复运行的大功率开关进行系统调研、分析地基础上,初步选定了RUV-31真空触发开关、TPI1-10k/50冷阴极闸流管以及GXG系列触发管作为备用开关。设计并研制了一套专门用于研究开关性能参数的试验平台以及三套满足开关触发要求的触发系统,实验研究结果表明TPI1-10k/50冷阴极闸流管具有低抖动、低电感、快电流上升速率等特点,可以很好满足系统的需求,最后对选定的冷阴极型TPl1-10k/50闸流管在工作电压40kV、工作电流16kA、脉冲宽度200ns、重复频率20Hz-50Hz条件下的抖动、延迟特性进行了详细的研究,包括储氢加热电压、直流预电离电流、辅助脉冲电流以及阳极电压对其抖动、延迟的影响。实验研究结果为实现商业化的中等高压开关在基于PFN-LTD技术脉冲功率源的应用提供了依据,并提高了系统的稳定性及可靠性。分析研究了负载阻抗变化对双线型脉冲形成网络直接给负载放电以及通过直线变压器(LTD)给负载放电时电压传递效率,能量传递效率以及峰值功率传递效率的影响,同时对两个单元模块输出的高压脉冲经过阴极杆感应叠加后输出波形质量开展了实验研究。在上述研究的基础上课题组研制出了一台由10个PFN-LTD单元模块感应叠加而成的紧凑型重复频率脉冲功率源,同时根据脉冲功率源的运行特点,课题组自行研制了配套的高频开关电源、控制系统、测量系统、磁芯复位系统等,脉冲功率源整体尺寸为为1.4m×2m×1.3m,系统总重量为2吨。目前实验研究结果表明在充电电压34kV时脉冲功率源可在1Hz重频下稳定工作,输出脉冲一致性很好且抖动较小,输出电压约为276.6kV,电流约为11.6kA,脉冲宽度约为223ns,前沿小于80ns。更多还原

【Abstract】 Because of the important military merit and civil foregrou, repetitive pulse-power generator is one of the important study direction for the pulse power technology. The compact repetitive pulse-power generator is one of the kernel technologies of high-power microwave (HPM). More attention has been progressively paid to the pulse power generator which based on the direct driving technology as one of the primary technical approaches for achieving the compact and repetitive of pulse-power generator, In this dissertation, the pulse power generator with a10-stage Pulse Forming Network-Linear Transformer Driver (PFN-LTD) module has been developed based on the detailed theoretical analysis, circuit simulations and basic experimental study. The designed idea and studied result are instructive for the further development of this kind of pulse power generator, and also set a good foundation for the realization of higher performance as well as more extensive applications. This dissertation mainly consists of the following aspects:The technological background and recent studied results related to direct driving technology is introduced. The key technology and developing direction about PFN-Transformer and PFN-Marx based on direct driving technology is discussed. At the same time, the potential technology approaches for achieving the compact and repetitive of pulse-power generator is analysed. The accelerator based on water-dielectric helical pulse forming line is theoretical analysed and designed. With considering the merit and drawbacks of the linear transformer and its application, the compact repetitive pulse power generator based on the PFN-LTD technology is firstly proposed. The designing goal is working voltage400-500kV, peak power8～10GW, pulse width200ns, working frequency50Hz.Basing on discussing the requirements on pulse forming module for PFN-LTD technology, the drawbacks of the pulse forming line (PFN) with solid/liquid dielectrics for forming long pulse and the pulse forming network with film capacitors for forming short pulse is detailed analyzed. A high energy density middling-high voltage pulse forming network which suit slowly charging was designed with a ceramic capacitor with low self-inductance. The experimental results indicate that the rise time of the high voltage pulse is less than40ns; the pulse width is about220ns when the matching load is1Q. The designed PFN can satisfy the needs of compact and lightweight application. The experimental results also indicate that the rise time of the high voltage pulse which is generated by the Blumlein pulse forming module is about50ns and the pulse width is about230ns when the matching load is2.5Ω. The charging voltage of the Blumlein pulse forming module is44kV. It set a good foundation for developing the compact pulse power generator. Through the finite element analysis and simulation, the induction of the switch part and the load part of PFN was simulated and studied. Basing on the analysis of the simulating result, an improved design of the switch part structure is introduced.The primary effecting factor for the rise time of the pulse which is output by the LTD is analyzed. The performance of the magnetic core effecting on the quality of the pulse is also discussed. Considering the nanocrystalline magnetic materials with relatively high saturation flux density, low loss and high Curie temperature has shown promise for significantly improving energy transfer efficiency and realize pulse power generator compact. A test stand is developed to measure the performance of the nanocrystalline magnetic materials which is made in China. Based on the test stand, a series of experiment are carried out for testing the B-H curve, pulse permeability. The mean length magnetic path and effective core area effect on energy transfer efficiency is studied. The insulated ability of oxidated film of the magnetic core which is natural formed also measured. The experimental results are instructive for the homemade nanocrystalline magnetic materials used in the LTD, inductive add, magnetic switch and pulse transformer.In this paper, the requirement of pulse power generator basing on PFN-LTD technology on the switch is analyzed. For switch delay of normal distribution, the effects switch jitter and single waveform’s rise time on the rise time of resultant waveforms are discussed when the multiple work synchronously. Based on the detailed investigation of the high power switch, the Triggered Vacuum Switches RUV-31, cold cathode thyratron TPI-10k/50and trigger switch GXG are choose primarily. A test stand and there trigger system are designed to measure the performance of switches. The experimental results showed that cold cathode thyratron TPI-10k/50with low jitter, low inductance and high dI/dt. It quite well meets the demand of the pulse power generator basing on PFN-LTD technology. Based on the trigger device, the research of trigger performance of TPI1-10k/50was done, including the influence of heater voltage, trigger current and direct pre-ionization current. At last, this switch worked under the condition of:voltage of40kV, current of16kA, pulse width of200ns, Pulse repetition rate of20Hz-50Hz. The jitter of TPI1-10k/50is about2ns. The experimental results are beneficial for the commercial middling-high voltage used in the pulse power generator for improving the stability and reliability.Through the theoretical analysis and simulation, the effects of impedance on the voltage transfer efficiency, energy transfer efficiency and peak power transfer efficiency when PFN discharges to the load directly and through LTD are discussed. Based on the foregoing study,10-stage PFN-LTD generator is designed and researched. According to the characteristic of the pulse power generator, we designed and manufactured high-frequency switching power supply, control system, measurement system, and restoration system. The dimension of the pulse power generator is about1.4mx2mx1.3m. The total weight is about two ton. The experimental results shown at a34kV charging voltage, the10-stage PFN-LTD generator can operate stably at1Hz, producing an output pulse of276.6kV pulse voltage,11.6kA pulse current,223ns pulse width,80ns rise time.更多还原