【作者】 梁天学；

【导师】 孙才新； 邱爱慈；

【作者基本信息】 重庆大学 ， 电气工程， 2007， 硕士

【摘要】 模块化直线型脉冲变压器驱动源(称为Linear Transformer Driver,简称LTD)是近年发展起来的一种新型脉冲功率驱动源新技术,模块化LTD模块之间串、并联使用非常方便。近几年,LTD脉冲前沿已从开始的微秒量级减小到百纳秒量级,使得LTD有可能直接驱动高功率激光、微波、电子束、离子束二极管以及Z-Pinch等离子体辐射等负载。其中,初级放电开关是LTD的关键器件之一,要获得快前沿的电流脉冲,要求开关的电感尽可能小;由于LTD初级采用数十至上百路并联工作,多个开关同时动作,每只开关都要求低抖动,解决开关低电感低抖动是LTD获得短脉冲和同步触发的关键。本文根据国内外模块化短脉冲LTD的最新进展和直接驱动负载的要求,研制适合于模块化快前沿LTD的±100kV,自感小于50nH的多级多通道气体火花开关。分析了影响火花开关电感和延时抖动的主要因素,总结了减小气体火花开关电感和延时抖动的方法;设计了一种绝缘子内抠槽平面支撑多级多通道开关中间电极的结构,解决了多电极开关中间电极固定时平行度和同轴度难以保证的问题;通过对开关的自击穿特性实验研究,表明电极在300℃高温烘烤20小时可以提高开关的自击穿电压及其稳定性;对开关欠压比、触发电压幅值、极性,隔离电阻大小对开关性能和稳定性的影响实验研究,表明通过提高开关工作欠压比、触发电压幅值和陡度可以减小开关的延时和抖动,开关在欠压比大于75%,触发电压大于70kV时,延时小于60ns,抖动小于4ns;采用短路放电的方法估算开关不同工作状态电感,研究了工作电压、触发电压对开关形成多通道的影响,研究表明开关随着工作电压和触发电压的升高开关电感减小,从自击穿时约46nH减小到最低约21nH,开关在触发条件下,工作电压越高,触发电压越高,越容易形成多通道;研制的多级多通道开关耐压±100kV,自感小于50nH,通流能力不小于50kA,已用于短脉冲LTD模块单元实验,LTD单元短路负载电流上升时间(10%～90%)约86ns,单个回路电感约270nH,满足短脉冲模块化LTD设计要求。更多还原

【Abstract】 Modular linear transformer driver (LTD) is a novel fast discharge high power pulsed source on primary storage energy. It can realize many LTD modules in series or parallel connection conveniently. During the last few years, the LTD can acquire the rise time of 100～200ns of high power pulse in abroad. It is probably that LTD can directly drive the high power laser, microwave, electron beam, ion beam diode and the Z–pinch plasma radiation load etc. The primary discharge switch is one of the key devices in LTD. For acquiring a short rise time of the LTD pulse current, it requests the switch inductance is possibly small. Because the LTD primary adopts many bricks parallel working, a number of switches must discharge synchronous and each switch requests a low jitter. Therefore solved the switch low inductance and low jitter is the key that the LTD acquires short pulse and synchronous triggering.According to the latest progress and direct-drive request of domestic and international modularization fast LTD, this paper develops a±100kV multi-gap multi-channel switch suitable for modularization fast LTD, the switch self inductance less than 50nH. Analyzed the main influence factor of spark switch inductance and jitter, the method to reduce inductance and jitter of the gas spark switch is putted forward. Designed a kind of insulator structure that dig a slot plane inside to support the middle electrode of the multi-gap switch, it solves middle electrode of the multi-electrode switch fix hardly parallelism and coaxial. The experiment studies the self-breakdown characteristic of the switch, the research results indicate that baking the switch electrode can raise self-breakdown voltage and its stability. The experiment studies the influence of the switch triggering breakdown characteristic of the switch with the working voltage ratio, trigger voltage, polarity and insulate resistance. The typical results are shown as follows: the postponing time as well as its jitter is decreasing while the working voltage ratio is increasing. The switch postponing time can achieve less than 60 ns with jitter less than 4 ns while the working voltage ratio larger than 75% and trigger voltage larger than 70kV. Faster voltage rise speed of switch gap can be gained from reducing the trigger resistance, therefore a small postponing time and jitter will be obtained. The postponing time and jitter falls dramatically with the increase of trigger voltage, it should be better to choose a trigger voltage as high as possible. The experiment studies the influence of the switch multi-channel formation with the switch operating voltage, triggering voltage through the method that the short discharge current estimates the switch inductance in different state. The experiment result shows that the switch inductance decreases with the increase of operating voltage and triggering voltage, from self-breakdown about 46nH to about 21nH. The operating voltage and trigger voltage is higher, the discharge channel is formed easier. The multi-gap multi-channel switch has already used for fast LTD module brick experiment. LTD brick short current rise time (10%～90%) is about the 86 ns. The brick inductance is about the 270nH. The experiment indicates the designed switch satisfies the requirement of the fast modular LTD.更多还原