Title :
The influence of O2 and N2 additives on impulse breakdown of SF6 in a non-uniform field
Author :
Zhou, L.M. ; Qiu, Y. ; Feng, Y.P.
Author_Institution :
Dept. of Electr. Eng., Xi´´an Jiaotong Univ., China
Abstract :
The influence of O2 and N2 additives on positive impulse breakdown of SF6 in a non-uniform field is reported. N2 and O2 were mixed in the ratio of 80/20 as a substitute for natural air, and the ratio was varied afterwards. Different impulse waveshapes were employed with wavefront being in the range from 0.6 to 80 μs and wavetail duration about 500 μs in all cases. Experiments showed that the optimal air content in the SF6/artificial air mixture was around 20% when the total gas pressure was 0.1, 0.2 or 0.3 MPa. By varying the ratio of N2 to O2 in the mixture containing 90% SF6, the highest breakdown voltage under 2/500 μs impulse was observed in the case of 5% N2 plus 5% O2. The relationship between the breakdown voltage and mixing ratio indicated that synergistic effects of SF6/O2, SF6/N 2 and O2/N2 were apparently different. The maximum breakdown strength is ascribed to the best synergism of O 2 and N2 acting together with SF6, and the synergistic effect of O2 and N2 in SF6 mixtures is related to the wavefront duration of the applied impulse voltage
Keywords :
SF6 insulation; electric breakdown; gaseous insulation; nitrogen; oxygen; 0.1 MPa; 0.2 MPa; 0.3 MPa; 500 mus; N2 additives; O2 additives; O2/N2; SF6; SF6-O2-N2; SF6/N2; SF6/O2; SF6/artificial air mixture; breakdown voltage; different impulse waveshapes; impulse breakdown; maximum breakdown strength; mixing ratio; nonuniform field; optimal air content; positive impulse breakdown; synergistic effects; Additives; Aluminum; Electric breakdown; Electrodes; Gases; Moisture; Silicon compounds; Sulfur hexafluoride; Testing; Voltage;
Conference_Titel :
Electrical Insulation, 1994., Conference Record of the 1994 IEEE International Symposium on
Conference_Location :
Pittsburgh, PA
Print_ISBN :
0-7803-1942-7
DOI :
10.1109/ELINSL.1994.401408
