Diagnostics of the pre-fault situation of the bolted current-carrying joint in the conditions of changing regime parameters

Authors

DOI:

https://doi.org/10.15587/2312-8372.2019.157865

Keywords:

weakening of bolted current-carrying joint, state diagnostics, random and deterministic mode of load current

Abstract

The object of research is the methods of non-destructive monitoring of the state of a bolted current-carrying joint under conditions of dynamically changing current load conditions and ambient temperature. One of the most problematic places in the modern conditions of economic development of enterprises is the reduction in the accident rate of production due to the weakening of the bolted current-carrying joint. Studies of the causes of stopping electrical equipment at a number of ferrous metallurgy enterprises, mining and processing complexes, in medical institutions have shown that in 1.5-2 % of cases the cause of an emergency shutdown of electrical equipment is the weakening of the bolted current-carrying joint. The main problem of the bolted current-carrying joint is the mechanical weakening of the contact density. The appearance of a temperature gradient in the place of a bolted joint is influenced by climatic parameters and dynamically changing modes of operating current loads and network voltage.

The study of operating parameters of the network and load currents is based on the use of a technique for monitoring the quality of electricity indicators using self-recording spectrum analyzers. In this study, the spectrum analyzer Fluk 435 (Ukraine) is used, the characteristics of which correspond to the ISO 9001 measurement system certificate. Statistical processing methods are used as the basis for processing the experimentally obtained data.

In the course of the study, the inequality between the measured temperature of the bolted current-carrying joint and the calculated temperature of the serviceable joint is determined. The inequality is fulfilled in the sections, the stationarity of which is determined for deterministic and random modes of change of the controlled parameters. The functions of Boolean variables are compiled, the disjunctive functions that determine the normal and pre-crash modes of the bolted joint are minimized. The obtained theoretical results allow developing algorithms and devices for diagnosing and protecting equipment.

This provides the opportunity to reduce the accident rate of the equipment. Compared with similar well-known protection equipment, taking into account the modes of load currents, mains voltage and ambient temperature provides a high sensitivity and accuracy of detecting the initial moment of loosening of a bolted current-carrying joint.

Author Biography

Valerii Kryvonosov, Pryazovskyi State Technical University, 7, Universytetska str., Mariupol, Ukraine, 87555

PhD, Associate Professor

Department of Biomedical Engineering

References

  1. Krivonosov, V. E., Zlepko, S. M., Virozub, R. M., Baranovskiy, D. M. (2017). Kriterii diagnostiki vintovykh soedineniy v ul'trazvukovoy tomograficheskoy apparature. Vіsnik Khmel'nits'kogo natsіonal'nogo unіversitetu. Serіya: Tekhnіchnі nauki, 1, 52–57.
  2. Kryvonosov, V. E. (2015). Pat. No. 107749 UA. Sposib kontroliu za stanom boltovykh ziednan elektroobladnannia, shcho pratsiuie zi zminnym navantazhenniam. MPK: G01N 27/24, H02K 15/12, G01N 25/72, H02H 5/04, H01R 31/00, G01N 27/20, G01R 13/00. No. a 201309491; declareted: 29.07.2013; published: 10.02.2015; Bul. No. 3, 4.
  3. Brady, J. (2011). Thermal Patterns Associated with Infrared Inspection of Electrical Systems. Available at: https://www.irinfo.org/05-01-2011-brady/
  4. Izmaylov, V. V., Naumov, A. E. (2008). Avtomatizirovannaya sistema prognozirovaniya ostatochnogo resursa elektrokontaktnykh soedineniy. Programmnye produkty i sistemy, 2, 73–75.
  5. A guide to low resistance testing (2017). Available at: https://www.techrentals.com.au/pdf_files/Megger_A_20Guide_20to_20Low_20Resistance_20Testing.pdf
  6. Kaplya, N. G., Kaplya, E. N. (2010). Pat. No. 2408120 RU. Ustroystvo dlya kontrolya temperatury kontaktnykh soedineniy v ustroystvakh, nakhodyashhimsya pod vysokim napryazheniem. MPK: H02H5/04. No. 2009115534/07; declareted: 24.04.2009; published: 27.12.2010; Bul. No. 36, 5.
  7. Genutis, D. A. (2006–2007). Infrared Inspections and Applications. NETA WORLD Winter. Available at: https://studylib.net/doc/18260220/infrared-inspections-and-applications
  8. Pat. No. CN 102636686 A (2012). Electrical heating tube detection device. 15.08.2012. Available at: https://patents.google.com/patent/CN203526081U/en
  9. Teslia, Yu. A., Diachenko, M. D. (2014). Pat. No. 104546 UA. Prystrii avtomatychnoho monitorynhu stanu kontaktnykh ziednan vysokovoltnykh pidstantsii i linii elektroperedach. MPK: H02H 5/04, H02G 15/12, H01R 13/02, H02G 15/08, G05B 19/05. No. a201301914; declareted: 18.02.2013; published: 10.02.2014; Bul. No. 3.
  10. Kennedy, R., Hope, J. (2013). Pat. No. 13/689340 USA. Dynamic Thermal Mapping. MPK: 702/64, 361/689. No. 20130138371; declareted: 29.11.2012; published: 30.05.2013.
  11. Kryvonosov, V. E., Pirotti, Ye. L. (2018). Pat. No. 127922 UA. Prystrii diahnostuvannia oslablennia boltovykh strumoveduchykh ziednan i obryvu strumoveduchykh chastyn systemy elektropostachannia elektropryimacha. MPK: H02H 5/04, H02K 15/12 / No. u201802711_2; declareted: 19.03.2018; published: 27.08.2018; Bul. No. 16, 4.
  12. Chistyakov, V. I. (1978). Kurs teorii veroyatnosti. Moscow, 224.

Published

2018-12-20

How to Cite

Kryvonosov, V. (2018). Diagnostics of the pre-fault situation of the bolted current-carrying joint in the conditions of changing regime parameters. Technology Audit and Production Reserves, 1(1(45), 50–57. https://doi.org/10.15587/2312-8372.2019.157865

Issue

Section

Technology and System of Power Supply: Original Research