Development of Extra High Voltage(400kN) Porcelain Insulator for Transmission Lines

765 kV용 400 kN 현수애자 개발

  • Published : 2003.08.01

Abstract

This paper was the research of high voltage suspension insulator (400 [kN]) including pottery stone, feldspar, clay and alumina of 17 [wt%]. The slurry was fabricated after ball milling mixed raw materials. Green compacts were made by the extrusion of jiggering method and were sintered at 1300[$^{\circ}C$] for 50 [min.] in the tunnel kiln. The sintered density was reached to 97% of theoretical density, and the bending strength was 1658 [k $g_{f}$/$\textrm{cm}^2$] and hardness and fracture toughness which was measured by ICL( indentation crack length ) method were 1658 (kgf/$\textrm{cm}^2$) and 27.5 [Gpa], respectively. In measurement of tana and insulation break voltage of 400 (kN) porcelain, tan$\delta$ took some numerical value between 17${\times}$10$_{-3}$ and 61${\times}$10$_{-3}$ and insulation break voltage value was 19.9$\pm$1.4 [㎸/mm]. The test was performed to research whether the shape of pin affect a overvoltage break load or not As a consequence, when a pin was designed a pin diameter 51 [mm] with the bottom form of two-step constructed with straight in the suspension insulator, Insulator showed overvoltage break load 52 [ton] of the highest value and reflected a fine characteristic in aged deterioration test which is one of the accelerated aging test. Also it could be confirmed a fine characteristic through performing the test that electrical property of insulator was established correctly in accordance with IEC 60383-1 standards.s.

Keywords

References

  1. W. M. Carty and U. Senapati, 'Porcelain-raw Materials, Processing, Phase Evolution and Mechanical Behavior', J. Am. Ceram. Soc., 81(1), 3-20 (1990) https://doi.org/10.1111/j.1151-2916.1998.tb02290.x
  2. K. Hamano, Z. Nakagawa and M. Hasegawa, 'Improvement of Mechanical Strength of Porcelain Bodies by Grinding of Raw Materials', J. Ceram. Soc. Jpn.(in Jpn), 100(8), 1066-1069 (1992) https://doi.org/10.2109/jcersj.100.1066
  3. J. E. Schroeder, 'Inexpensive High Strength Electrical Porcelain', Am. Ceram. Soc. Bull., 57(10), 526 (1978)
  4. L. Mattyasovszky-Zsolnay, 'Mechanical Strength of Porcelain', J. Am. Ceram. Soc., 40(9), 299-306 (1957) https://doi.org/10.1111/j.1151-2916.1957.tb12626.x
  5. S. K. Khandelwal and R. L. Cook, 'Effect of Alumina Additions on Crystalline Constituents and Fired Properties of Electrical Porcelains', Am. Ceram. Soc. Bull., 49(5), 522-526 (1970)
  6. W. E. Blodgett, 'High Strength Alumina Porcelains', Am. Ceram. Soc. Bull., 40(2), 74-77 (1961)
  7. R. Harada, N. Sugiyama and H. Ishida, 'A1203-strengthened Feldspathic Porcelain Bodies : Effect of the Amount and Particle Size of Alumina', Ceram. Eng. Sci. Proc., 17(11), 88-98 (1996)
  8. K. Niihara, R. Morena and D. P. H. Hasselman, 'Evaluation of KIc of Brittle Solids by the Indentation Method with Low Cracks-to-indent Ratio', J. Mater. Sci. Lett., 1, 13-16 (1982) https://doi.org/10.1007/BF00724706
  9. H.S. Kim, 'Development of Porcelain Suspension Insulator with High Reliability for the Distribution Line', Report, Kepco (1995)
  10. H. Nozaki, H. Inoue, 'High Tensile Strength Suspension Insulators with Multi-Step Embedded Pins', U. S. Patent No. 4,396 ,798(1983)