【作者】 莫登斌；

【导师】 孙才新；

【作者基本信息】 重庆大学 ， 电气工程， 2007， 硕士

【摘要】 脉冲功率技术不仅在国防军事和科技研究中起着非常重要的作用,而且在工业应用、生物医学和环境保护等民用领域中展现出了强大的应用潜力。但迄今为止还没有一台比较适合于商用的纳秒脉冲发生器,因此研制出高性能的纳秒脉冲发生器具有重要的科学意义和应用价值。本文结合脉冲功率技术和火花开关技术,研制出了一套基于Blumlein传输线的纳秒脉冲发生装置。分别从波过程和等值电路的角度分析了利用Blumlein传输线产生高压脉冲的工作原理,并用电路仿真软件Pspice的仿真结果验证了理论分析,同时还仿真研究了杂散参数对Blumlein型脉冲发生器输出波形的影响。结果表明,放电回路的杂散电感、负载两端间杂散电容和负载前端对地杂散电容使脉冲前沿和后沿变缓,且上升时间和下降时间近似与杂散参数成正比;放电回路电阻使脉冲后沿出现严重的拖尾现象;输出回路杂散电感使脉冲前沿和后沿产生过冲;负载后端对地杂散电容也使脉冲前沿产生过冲,但后沿下降到1/2电压处发生严重畸变。研究了场畸变火花开关的气压、间距、电场类型和电极结构,通过合理地设计绝缘结构,减小了开关尺寸;应用电场仿真软件Femlab对开关间隙的电场分布进行仿真,验证了开关电气设计的合理性,从理论上计算了开关的性能参数;还对开关的机械结构进行了设计和加工。开关试验研究了击穿时延与抖动和欠压比、触发电压之间的关系,以及开关的触发范围和触发阈值,结果表明开关工作在气压大于2atm,欠压比大于80%,触发电压大于15kV的状态下,开关击穿时延小于100ns,抖动小于10ns,触发范围大于55%,触发阈值小于10kV,满足设计要求。对Blumlein型纳秒脉冲发生器的各部分进行了具体设计,完成了样机的装配。对元器件进行了选择和参数计算,设计出了用于测量开关触发脉冲的电阻分压器以及分压器的标定脉冲源,并对分压器进行了阶跃响应实验。对Blumlein型纳秒脉冲发生器进行了实验室总体调试和输出波形的测量,结果表明该装置满足设计要求,为实际应用奠定了基础。更多还原

【Abstract】 Pulse power technology not only plays more and more important role in military and high-tech research, but also exhibit good application potential in many fields,such as industry, biomedicine and environment protection and so on. But so far, there is no one commercial nanosecond pulse generator. Therefore, it has vital scientific significance and the application value to develop nanosecond pulse generator with high performance. This thesis developed a nanosecond pulse generator based on blumlein transmission line according to pulse power technology and the spark switch technologyThe principle that Blumlein transmission line generates high-voltage pulse was analyzed theoretically from the view of points of transmission of electromagnetic wave and its equivalent circuit. The circuit simulation result with software Pspice validates the theoretical analysis. The influence of stray parameters in Blumlein-type pulse generator on the output pulse was also simulated. The results have show that stray inductance in discharge loop, stray capacitance between the two terminals of load and the stray capacitance between the front end of load and the earth slow the rise rate of front edge and fall rate of back edge, and the rise time and fall time are approximately in direct proportion to the stray parameters. The stray resistance in discharge loop leads to fall step by step at the end of pulse. The stray inductance in output loop results in overshoots at the front and back edge. Although the stray capacitance between the back end of load and the earth can also cause overshoot at the rise edge of pulse, the back edge of pulse is distorted and the fall time increases greatly. The simulation provides reference for the development of pulse generator and improving the rise edge of pulse.The air pressure, gap distance, field type and electrode structure of field distortion spark switch were studied in detail. Reasonable insulation structure reduced the size of the switch. The field distribution in the gap was simulated with software Femlab, and the result validates the rationality of electrical design. The characteristic of the switch were calculated theoretically. The switch was design concretely in mechanical size and then machined. The experiments were carried out to study the influence of working voltage ratio and triggering voltage on breakdown time delay as well as its jitter. The triggering range and triggering threshold were also studied. The experimental results indicated that the time delay was less than 100ns and jitter less than 10ns when the air pressure less than 2atm, voltage ratio larger than 80% and triggering voltage larger than 15kV. Moreover, the triggering range was larger than 55% and triggering threshold less than 10kV. The experimental results indicated that the switch can meet the design demand.In the last part, the design of each part of the Blumlein-type nanosecond pulse generator and the prototypical assembly were completed. The components were selected and their parameters were calculated. A resistor divider for measuring triggering voltage and its corresponding pulse source for step response experiment of divider were designed. The Blumlein-type nanosecond pulse generator was debugged overall and the output waveform was measured in laboratory. The result shows the equipment can satisfy the design requirements, which indicates the equipment lays a foundation for practical application.更多还原