access icon openaccess Influence of trace H2O and O2 on SF6 decomposition products under arcing conditions in electric power equipment

This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
Received 29/08/2018, Accepted 19/09/2018, Published 24/10/2018

SF6 has been widely used as an insulating and arc extinguishing medium in electric power equipments. Detection of gas decomposition products is an important means for condition monitoring and fault diagnosis. Trace H2O and O2 have a significant influence on the species and concentrations of SF6 decomposition products. It is important to explore the influence mechanism of trace H2O and O2 on SF6 decomposition products under arcing conditions. A series of SF6 decomposition tests were carried out on a 40.5kV SF6 circuit breaker, and a gas chromatograph and an electrochemical sensor were used to measure decomposed components. First, the H2O content remained constant, and the O2 content and arcing energy changed in the tests. It has been found that the decomposition products of SF6 are SOF2, SO2, CO, CO2, CF4, C2F6 and C3F8. Then, the O2 content remained constant, and the H2O content changed. The decomposition products are mainly SOF2, SO2, CO and CO2. Concentrations of all these decomposition products increase first and then tend to be stable slowly over time, but change differently with the increase of H2O and O2 contents, because H2O and O2 play different roles in the formation process of each decomposition characteristic components.

Inspec keywords: chromatography; condition monitoring; oxygen; decomposition; circuit breakers; electrochemical sensors; sulphur compounds; fault diagnosis; arcs (electric); carbon compounds

Other keywords: electrochemical sensor; SO2; gas decomposition products; C3F8; CO; condition monitoring; CO2; fault diagnosis; C2F6; CF4; H2O; SOF2; electric power equipment; decomposition tests; decomposition characteristic component; arcing conditions; gas chromatograph; insulating medium; circuit breaker; arc extinguishing medium; arcing energy; formation process; voltage 40.5 kV; O2; SF6

Subjects: Switchgear; Inorganic insulation; Chemical sensors; Gaseous insulation, breakdown and discharges

References

    1. 1)
      • 11. Boudene, C., Cluet, J.L., Keib, G., et al: ‘Identification and study of some properties of compounds resulting from the decomposition of SF6 under the effect of electrical arcing in circuit-breakers’, Rev. Gen. Electr., 1974, (Special Issue), pp. 45–78.
    2. 2)
      • 7. Yan, X.-L., Wang, C.-Y., Yang, R., et al: ‘Fault diagnosis of high voltage switchgears by decomposition products of SF6’, Power Syst. Technol., 2011, 35, (12), pp. 118–123.
    3. 3)
      • 10. Wan, L., Liu, H., Tang, J., et al: ‘Analysis of SF6 decomposition byproducts under two kinds of PD defects’. Int. Conf. High Voltage Engineering and Application, Chongqing, China, 2009, pp. 430–432.
    4. 4)
      • 4. Hirooka, K., Kuwahara, H., Noshiro, M., et al: ‘Decomposition products of SF6 Gas by high current arc and their reaction mechanism’, IEEJ Trans. Fundam. Mater., 1975, 95, (6), pp. 14–19.
    5. 5)
      • 14. Chervy, B., Gleizes, A., Razafinimanana, M.: ‘Thermodynamic properties and transport coefficients in SF6-Cu mixtures at temperatures of 300–30000 K and pressures of 0.1–1 MPa’, J. Phys. D: Appl. Phys., 1994, 27, (6), pp. 1193–1206.
    6. 6)
      • 8. Yan, X.-L, Wang, C.-Y., Ji, Y.-S., et al: ‘Detection techniques for decomposition products of SF6 in switchgears’, Power Syst. Technol., 2010, 34, (Sup.2), pp. 246–250.
    7. 7)
      • 6. Belmadani, B., Casanovas, J., Casanovas, A.M., et al: ‘SF6 decomposition under power arcs. I. Physical aspects’, IEEE Trans. Electr. Insul., 2002, 26, (6), pp. 1163–1176.
    8. 8)
      • 13. Hirooka, K., Shirai, M.: ‘Thermal characteristics of SF6’, J. Am. Chem. Soc., 1980, 2, (2), pp. 165–169.
    9. 9)
      • 3. Christophorou, L.G., Olthoff, J.K., Van Brunt, R.J.: ‘Sulfur hexafluoride and the electric power industry’, IEEE Electr. Insul. Mag., 1997, 13, (5), pp. 20–24.
    10. 10)
      • 2. Tang, J., Liu, F., Zhang, X., et al: ‘Partial discharge recognition through an analysis of SF6 decomposition products part 1 decomposition characteristics of SF6 under four different partial discharges’, IEEE Trans. Dielectr. Electr. Insul., 2012, 19, (1), pp. 29–36.
    11. 11)
      • 12. Umemura, S., Aoki, T.: ‘Effects of CO2 ‘atmosphere on contact resistance characteristic of noble metal contacts’, IEEE Trans. Compon., 1992, 15, (2), pp. 258–265.
    12. 12)
      • 9. Ji, Y.-S., Wang, C.-Y., Yang, R., et al: ‘Measuring technique of SF6 decomposition products and its application to fault diagnosis of GIS’, High Volt. Appar., 2011, 47, (2), pp. 100–103.
    13. 13)
      • 1. Chu, F.Y.: ‘SF6 decomposition in gas-insulated equipment’, IEEE Trans. Electr. Insul., 1986, 21, (5), pp. 693–725.
    14. 14)
      • 5. Belmadani, B., Casanovas, J., Casanovas, A.M.: ‘SF6, decomposition under power arcs. II. Chemical aspects’, IEEE Trans. Electr. Insul., 1991, 26, (6), pp. 1177–1182.
http://iet.metastore.ingenta.com/content/journals/10.1049/joe.2018.8832
Loading

Related content

content/journals/10.1049/joe.2018.8832
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Loading