Engineering Transactions, 52, 3, pp. 135–152, 2004

Acoustic Method of On-Site Examination of Ceramic Long-Rod Insulators

P. Ranachowski
Institute of Fundamental Technological Research PAS
Poland

F. Rejmund
Wrocław University of Technology
Poland

J. Fleszyński
Wrocław University of Technology
Poland

This paper presents the new non-destructive ultrasonic method for investigation of long-rod insulators working as the element of station isolating switches. The 110/6 kV stations belonged to domestic industrial power engineering. The main aim of the research was to establish a close correlation between the degree of defectiveness of electrotechnical porcelain and parameters of ultrasonic wave propagation and attenuation. In addition, the causes of breakage of insulator SWZPAK-110 from the year 1975 were ascertained. This ceramic element underwent detailed structural and comparative acoustic measurements. The experimental investigations were per-formed using a specially designed and constructed measuring equipment. Besides founding the original technological and also direct causes of breakage of the insulator mentioned above, the most significant achievement of the work was elaboration of the methodology of ultrasonic measurements applied directly to objects in exploitation. The presented method was used for the analysis of quality of the group of 43 insulators after long-term exploitation on isolating switches.
Keywords: ultrasonic measurement; ceramic insulator; electrotechnical porcelain; microstructure
Full Text: PDF

References

J. MIGDALSKI, Engineering of reliability, ATR Bydgoszcz, ZETOM Warszawa, 1992.

F. REJMUND, P. RANACHOWSKI, Experimental methods of determination of short and long-term mechanical strength of ceramic insulators, Engineering Transactions, 46, 131–139, 1998.

J. RANACHOWSKI, J. WEHR, Application of ultrasonic flaw detection to testing of ceramic high-voltage insulators, Electrotechnical Review, 10/11, 689–695, 1955.

J. WEHR, Measurements of velocity and attenuation of ultrasonic waves, PWN, Warszawa 972.

H.E. RYLL-NARDZEWSKA, J. RANACHOWSKI, Ultrasonic investigation of elastic properties of the ceramic materials, [in:] Electroceramics – selected methods of testing, vol. 2, 35–48, PWN, Warszawa–Poznań 1982.

J.K. MAC KENZIE, The elastic constants of a solid containing spherical holes, Proc. Phys. Soc., B. 63, 2, 1950.

M. BOSEK, J. RANACHOWSKI, Long-rod insulator testing using ultrasonic method, Non-destructive methods of materials investigation, Problems of Polish Science Reports, Ossolineum, 24, 1965.

Z. GACEK, Diagnosis of mechanical properties of long-rod type insulators, Materials of Conference Electrotechnical Ceramics Production Exploitation, Development, Boguchwała, 111–117, 1994.

J. RANACHOWSKI, P. RANACHOWSKI, F. REJMUND, E. KANIA, J. BERTRAND, Expertise of structure homogeneity of different types of insulators at switching station 110 kV of transformer station Polkowice Glówne of ZG KGHM Polish Copper S.A., Institute of Electrical Engineering Fundamentals of Wrocław Technical University, Warszawa 1997.

J. RANACHOWSKI, J. BERTRAND, P. RANACHOWSKI, F. REJMUND, E. KANIA, Expertise of causes of breakdown of switchgear post insulator 110 kV SWZPAK-110 type from 1976 and possibility of defectiveness measurement of this type insulators as well as LP-75 line insulators, Warszawa 1997.

W.D. KINGERY, Introduction to ceramics, John Wiley and Sons, New York – London Chapter 13, 1960.

IEC Publication 672-1:1995 Ceramic and glass-insulating materials, Part 1: Definitions and classification. IEC Publication 672-2:1999 Ceramic and glass-insulating materials, Part 2: Methods of testing. IEC Publication 672-3:1997 Ceramic and glass-insulating materials, Part 3: Specifications of individual materials.




Copyright © 2014 by Institute of Fundamental Technological Research
Polish Academy of Sciences, Warsaw, Poland