【摘要】 采用质量作用定律法计算压强0.1².0 MPa、温度40 000 K到300 K下SF₆等离子体组分体积分数,分析热态SF₆介质（3 500 K到300 K）的成分构成及其变化过程。采用两项近似法求解玻尔兹曼方程,计算不同折合电场下热态SF₆介质中电子能量分布函数,分析不同碰撞过程中各微观粒子的折合电离系数和折合吸附系数,得到热态SF₆介质的折合击穿场强,通过300 K下SF₆气体击穿场强实验值验证了计算方法的准确性。研究表明:弧后热态SF₆介质绝缘强度恢复过程中,温度下降到3 500 K到2 300 K时,热态SF₆介质主要成分为绝缘能力较低的F、S、S2、F2,折合击穿场强值在30 Td（1 Td=1×10-21Vm2）左右;温度下降到2 300 K到1 500 K时,分解物迅速复合为绝缘性能优异的SF₆,折合击穿场强急剧上升至355 Td附近。研究结果可为揭示热态SF₆介质绝缘强度恢复机理,解决高压SF₆断路器弧后重击穿导致开断失败等问题奠定理论基础。更多还原

【Abstract】 In this paper,the mass action law method was used to calculate the component content of SF₆ plasma in apressure range 0.1².0 MPa and temperature 40 000 K to 300 K.The composition and variation process of hot SF₆ with temperature between 3 500 K and 300 K were analyzed. First,a two-term approximate method was applied intosolution of Boltzmann equation to obtain the electron energy distribution function of hot SF₆ under different reducedelectric field.Then,through analyzing reduced ionization coefficient and reduced adsorption coefficient of microscop-ic particles,the breakdown field strength of hot SF₆ was obtained.Finally,the accuracy of this method was proved bythe experimental testing on SF₆ breakdown field strength at 300 K.Results show that during the insulation strength re-covery process of hot SF₆ after arcing,when the temperature decreases to 3 500 K to 2 300 K,the main components ofhot SF₆ are F,S,S2,and F2,which with low insulating strength.At the same time,the breakdown strength is about 30 Td（1 Td=1×10-21 Vm2）.When the temperature drops to 2 300 K to 1 500 K,the decomposers rapidly recombine into SF₆,and the breakdown strength sharply rises to about 355 Td.Results in this paper provide a theoretical foundation for re-vealing the recovery mechanism of hot SF₆ dielectric strength and solving the problems such as breaking failurecaused by re-strike in high voltage SF₆ circuit breakers.更多还原