自触发开关在不同脉冲前沿下的击穿特性

Breakdown Characteristics of Self-triggered Switches Under Different Voltage Rise-time

在击穿稳定性要求较高、外触发不便的脉冲功率装置中,自触发的气体开关成为一项重要选项。其中,基于紫外预电离技术的自触发开关已有多型开关成功应用于脉冲功率装置。在简要介绍紫外预电离开关击穿过程的基础上,着重分析在不同时间尺度、不同自触发信号引入方式情况下影响开关击穿特性的主要因素。实验分别测试了几十纳秒、百纳秒、微秒、几十微秒等4种脉冲前沿下开关的击穿特性。实验数据表明:该类型开关在击穿电压的分散性控制上表现比较优越,可小于1.5%;开关击穿时间抖动与承受脉冲电压的前沿正相关,可以达到脉冲时间前沿的1%左右;由于自触发开关触发能量小,很难在微秒以上前沿脉冲电压下获得几纳秒的时间抖动,可通过降低开关前级储能模块电感,减小开关承受脉冲前沿来获得更低的时间抖动。

Self-triggered gas switch is an important option in pulsed power equipment with high breakdown stability requirements and inconvenient external trigger.The self-triggered switch based on UV-illumination technology has been successfully applied to the pulsed power equipment.In this paper,based on the breakdown process in the UV illuminated switch,main factors affecting the breakdown characteristics under different time scales and self-triggered methods are analyzed.The breakdown characteristics of the switch under different voltage rise-time are tested by experiments,including tens of nanoseconds,hundreds of nanoseconds,several microseconds and tens of microseconds.The experimental results show that the self-triggered switch has a lower breakdown voltage jitter,which can be less than 1.5%.And the breakdown time jitter of the switch can be limited below 1%of the rise-time.However,due to low trigger energy of self-triggered switch,it is difficult to obtain a lower jitter below several nanoseconds when the voltage rise-time is above several microseconds.A lower time jitter can be achieved by reducing the inductance of the energy storage module before the switch and reducing the rise-time charging on the switch.