中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2013年
19期
200-207
,共8页
赵虎%李兴文%贾申利%刘之方%董勤晓
趙虎%李興文%賈申利%劉之方%董勤曉
조호%리흥문%가신리%류지방%동근효
绝缘特性%热态气体%SF6-CF4%临界击穿场强%Boltzmann方程
絕緣特性%熱態氣體%SF6-CF4%臨界擊穿場彊%Boltzmann方程
절연특성%열태기체%SF6-CF4%림계격천장강%Boltzmann방정
dielectric properties%hot gas%SF6-CF4%critical electric field%Boltzmann equation
热态SF6及其替代或混合气体的临界击穿场强特性是评估弧后电击穿的基础数据。基于两项近似求解Boltzmann方程的方法,得到了1个大气压下热态50%SF6-50%CF4混合气体的电子能量分布函数、折合电离反应系数和折合吸附反应系数,进而确定了混合气体的折合临界击穿场强。结果表明:在1个大气压下,当气体温度高于1800 K 时,50%SF6-50%CF4混合气体的折合临界击穿场强高于纯SF6;当温度高于2600 K时,与纯SF6和SF6-N2的情况不同,由于CF4分解物的影响,50%SF6-50%CF4混合气体的折合临界击穿场强随温度升高而增大。此外,还计算了1个大气压下不同比例冷态SF6-CF4混合气体的折合有效电离系数和折合临界击穿场强,并通过与已有结果的对比,验证了计算方法和参数的有效性。
熱態SF6及其替代或混閤氣體的臨界擊穿場彊特性是評估弧後電擊穿的基礎數據。基于兩項近似求解Boltzmann方程的方法,得到瞭1箇大氣壓下熱態50%SF6-50%CF4混閤氣體的電子能量分佈函數、摺閤電離反應繫數和摺閤吸附反應繫數,進而確定瞭混閤氣體的摺閤臨界擊穿場彊。結果錶明:在1箇大氣壓下,噹氣體溫度高于1800 K 時,50%SF6-50%CF4混閤氣體的摺閤臨界擊穿場彊高于純SF6;噹溫度高于2600 K時,與純SF6和SF6-N2的情況不同,由于CF4分解物的影響,50%SF6-50%CF4混閤氣體的摺閤臨界擊穿場彊隨溫度升高而增大。此外,還計算瞭1箇大氣壓下不同比例冷態SF6-CF4混閤氣體的摺閤有效電離繫數和摺閤臨界擊穿場彊,併通過與已有結果的對比,驗證瞭計算方法和參數的有效性。
열태SF6급기체대혹혼합기체적림계격천장강특성시평고호후전격천적기출수거。기우량항근사구해Boltzmann방정적방법,득도료1개대기압하열태50%SF6-50%CF4혼합기체적전자능량분포함수、절합전리반응계수화절합흡부반응계수,진이학정료혼합기체적절합림계격천장강。결과표명:재1개대기압하,당기체온도고우1800 K 시,50%SF6-50%CF4혼합기체적절합림계격천장강고우순SF6;당온도고우2600 K시,여순SF6화SF6-N2적정황불동,유우CF4분해물적영향,50%SF6-50%CF4혼합기체적절합림계격천장강수온도승고이증대。차외,환계산료1개대기압하불동비례랭태SF6-CF4혼합기체적절합유효전리계수화절합림계격천장강,병통과여이유결과적대비,험증료계산방법화삼수적유효성。
The reduced critical electric field strength is an important indicator for the evaluation of dielectric breakdown of SF6 and its mixtures. The electron energy distribution function, reduced ionization coefficient and attachment coefficient of SF6-CF4 mixtures were obtained at 1atm and gas temperatures to 3000K, by two-term Boltzmann equation analysis. Then the reduced critical electric field strength could be determined. The results show that, at temperature above 1 800 K, the reduced critical electric field strength of 50%SF6-50% CF4 mixture is higher than SF6 gas; at temperature beyond 2600K, different from the cases in pure SF6 and SF6-N2 mixtures, due to the dissociation of CF4, the reduced critical electric field strength of 50%SF6-50%CF4 mixture increases with the temperature rising. In order to validate the calculation method and parameters, the reduced effective ionization coefficient and reduced critical electric field strength of SF6-CF4 mixtures under ambient temperature and 1 atm were calculated and compared with other literatures. The comparison results confirmed the validity of the presented calculation method and parameters.