摘要
在激光惯性约束聚变的前级泵浦能源中,脉冲功率气体开关大电流电弧的电流上升率和注入能量较高,电弧向外剧烈膨胀产生巨大的冲击波超压,可能严重破坏开关结构。结合等离子体运动与冲击波理论建立电弧膨胀能量平衡方程,利用定绝热指数和时间自相似两种解法得到了本质相同的电弧半径与冲击波超压峰值时空变化的解析式,证明了电流上升阶段的超压峰值与电流上升率的4/5次方成正比。不同电流和开关参数的仿真计算表明,电弧冲击波超压峰值在时空上迅速衰减,且与电流上升阶段的能量注入速率最相关,同时也受能量注入总量、电弧电导率、气体密度、电极间距影响。协同改变电弧电流上升率等参数,可减小开关内冲击波超压,从而为冲击大电流开关的维护、改进与研制提供一定的理论指导。
High-current arc in a pulse power gas switch has a high current rising rate and energy injection in the pre-pump energy of laser inertial confinement fusion,and the dramatic expansion of the arc can produce a huge shock wave overpressure,which may cause serious damage to the switch structure.Consequently,the plasma motion and shock wave theory are combined to establish an arc expansion energy balance equation,and two solutions of constant adiabatic exponent and time self-similarity are adopted to obtain analytical formulas for arc radius that is essentially the same and for temporal and spatial variation of the peak overpressure.It is proven that the peak overpressure in the current rising phase is proportional to the 4/5 th power of the current rising rate.Simulation calculations with different current and switch parameters show that the peak shock wave overpressure decays rapidly in time and space.It is most related to the energy injection rate in the current rising phase,and is also affected by the total energy injection,arc conductivity,gas density,and electrode spacing.By changing the arc current rising rate and other parameters in coordination,the internal overpressure of the switch can be reduced,providing certain theoretical guidance for the maintenance,improvement and development of the high-current impulse switch.
作者
宫鑫
沈昊
戴宏宇
郭景润
李黎
GONG Xin;SHEN Hao;DAI Hongyu;GUO Jingrun;LI Li(State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第12期4412-4419,共8页
High Voltage Engineering
基金
国家自然科学基金(51777082,52077091)。
