Post-breakdown dielectric recovery characteristics of high-pressure liquid co2 including supercritical phase
Post-breakdown dielectric recovery characteristics of high-pressure liquid co2 including supercritical phase
复制标题
包括超临界相的高压液态co2的击穿后介电恢复特性
DOI：
10.1109/tdei.2014.6832252
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发表时间：
2014
影响因子：
3.1
通讯作者：
H. Akiyama
中科院分区：
文献类型：
--
作者：
Z.B. Yang;S.H.R. Hosseini;T. Kiyan;S. Gnapowski;H. Akiyama
本文描述了实验研究的结果，以评估击穿后的相变和/或密度变化对液体和超临界CO2介电恢复特性的影响。该研究旨在探索利用超临界二氧化碳开发高重复率脉冲功率开关的可能性。实验装置包括一个半径为10 mm、间距为50 μm的球对球电极结构。三相加压CO2；实验采用亚临界液相（SLS）、压力高于临界点的液相（LHCP）和超临界相（SC）。实验结果表明，SC co2具有非常短的恢复时间，使其成为MHz范围高重复开关的合适流体。在SLS中，击穿后阶段由电极之间等离子体通道的气相和液相组成，气泡的交替膨胀-收缩运动行为决定了介电恢复特性。SC的击穿后阶段与LHCP相似，击穿后产生一个低密度区，密度变化状态决定了介电恢复特性。低密度区域可以被周围介质压缩，从而大大缩短恢复时间。
The paper describes results of experimental studies to evaluate the effects of phasechange and/or density variation at the post-breakdown on the dielectric recovery characteristics of liquid and supercritical CO2. The study aims to explore the possibility of using supercritical CO2 to develop high-repetition-rate pulsed-power switches. The experimental setup consisted of a sphere-to-sphere 10 mm radius electrodes configuration with 50 μm gap distance. Three phases of pressurized CO2; subcritical liquid state (SLS), liquid with pressure higher than critical point (LHCP), and supercritical phase (SC), were used for the experiments. Experimental results revealed that SC CO2has a very short recovery time making it an appropriate fluid for MHz range highly-repetitive switches. Post-breakdown stage in SLS consisted of gas phase and liquid phase at the plasma channel between the electrodes, with the alternative expansion-contraction motion behavior of gas bubble determining dielectric recovery characteristics. Post-breakdown stages in SC were similar to those in LHCP, generating a low density region at the post-breakdown, where the state of density variation determined dielectric recovery characteristic. The low density region could be compressed by the surrounding medium, resulting in a considerably shorter recovery time.