Breakdown behavior of cryogenic liquids in the presence of thermal bubbles under ramped voltage
Breakdown behavior of cryogenic liquids in the presence of thermal bubbles under ramped voltage
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斜坡电压下热气泡存在下低温液体的击穿行为
DOI：
10.1109/14.83690
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
K. Saita
中科院分区：
文献类型：
--
作者：
M. Hara;H. Koishihara;K. Saita
在液氮和氦气中，模拟大型超导磁体线圈的失超条件，测量了V-t特性，观察到了热泡在斜坡电压下的变形。根据实验结果，根据电压斜率的不同，将液体冷却剂在热气泡存在下的击穿过程分为3类：（1）击穿未变形气泡和周围低温液体组成的复合绝缘系统，击穿电压快速上升，如标准雷电冲击电压;（2）在上升时间为毫秒的电场作用下，强伸长气泡的击穿;以及（3）通过差距的汽桥击穿，该汽桥由固定在具有热点的电极上的气泡的生长形成，在大约100 ms内产生电场。>
V-t characteristics were measured and the thermal bubble deformation was observed in liquid nitrogen and helium with a ramped voltage, simulating the quenching conditions in large superconducting magnet coils. From the experimental results, the breakdown process of liquid coolants in the presence of thermal bubbles was classified into three categories depending on the voltage slope: (1) breakdown through a composite insulation system of undeformed bubbles and surrounding cryogenic liquid with fast rising voltage such as the standard lightning impulse voltage; (2) breakdown through a strongly elongated bubble by an electric field with the rise time of milliseconds; and (3) breakdown through a vapor bridge of the gap, formed by growth of a bubble fixed on an electrode with a hot spot, by electric fields rising in approximately 100 ms. >