Title :
Breakdown and prebreakdown characteristics of SF6/CF4 mixtures in nonuniform electric field
Author :
Ziomek, W. ; Kuffel, E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Manitoba Univ., Winnipeg, Man., Canada
Abstract :
Measured prebreakdown and breakdown voltage characteristics of SF 6-CF4 mixtures are presented. The investigated gas insulated system consisted of point-to-sphere electrode configuration placed in a laboratory gas chamber. The measurements were carried out at the pressure of mixture equal to 300 kPa. The content of SF6 in CF4 was changed from 0% to 100%. The interelectrode gap was varied from 5 mm to 30 mm. Breakdown characteristics were measured for AC, DC and impulse voltages. Prebreakdown activity was analyzed under AC voltage using a wide-band PD detector and a coupled PRPD analyzer. The quantities characterizing PD intensity were analyzed, including energy spectrum of pulses, phase distributions of PD pulses´ charge and the number of pulses as a function of phase. Special attention was paid to 25% SF6-75% CF4 mixture, because of its superior electric strength observed particularly under AC and DC voltages
Keywords :
SF6 insulation; 300 kPa; 5 to 30 mm; AC voltage; PD intensity; SF6-CF4; SF6/CF4 mixtures; breakdown voltage characteristics; coupled PRPD analyzer; energy spectrum; gas insulated system; impulse voltages; interelectrode gap; laboratory gas chamber; nonuniform electric field; phase distributions; point-to-sphere electrode; prebreakdown voltage characteristics; voltage measurement; wide-band PD detector;
Conference_Titel :
High Voltage Engineering, 1999. Eleventh International Symposium on (Conf. Publ. No. 467)
Conference_Location :
London
Print_ISBN :
0-85296-719-5
DOI :
10.1049/cp:19990744
