Al_2O_3陶瓷在脉冲电压下的激光触发沿面闪络特性研究

Study of Al_2O_3 Ceramics' Laser-Triggered Surface Flashover Characteristics with Pulsed Voltage

为研究脉冲电压下的激光触发沿面闪络特性,在试验室中建立了精确的激光触发沿面闪络试验系统,解决了激光脉冲与试品上所加脉冲电压的同步问题,在此基础上应用平板电极和柱状绝缘材料进行了激光触发沿面闪络试验。试验中采用铜材料平板电极,试品为Al2O3材料圆柱绝缘材料,试验中激光波长为1 064/532nm并聚焦成长方形光斑,得到在不同的激光能量密度及施加电压下的闪络时延和抖动。研究表明:激光能量密度越大、施加电压越高,闪络时延和抖动越小;532nm波长激光触发的时延小于1 064nm波长激光触发的时延;真空条件下的时延和抖动均小于空气条件下的时延和抖动。

With the aim of studying the characteristics of laser-triggered surface flashover with pulsed voltage, synchronization problem of laser pulse and voltage pulse is solved through a high precision laser trigger system is built up in test system. Experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators based on the test system. The material of electrode is copper and the material of insulator is Al2O3. Laser pulse's wavelengths are 532 nm and 1 064 nm, and laser is focused with rectangle. The flashover delay time and jitter time are obtained through experiment, and the results of experiment show that flashover delay time and jitter time decrease with increase of pulsed voltage or laser energy density, the delay time of 1 064 nm laser trigger is larger than that of 532 nm laser trigger, and the delay time and jitter time in vacuum condition are less than the delay time and jitter time in air condition.