The usage of capacitive distributors for measuring voltages of 6 (10) kV tire sections

2022;
: pp. 55 - 61
1
Lviv Polytechnic National University
2
Lviv Polytechnic National University, Department of Electric Power Engineering and Control Systems
3
Lviv Polytechnic National University

One of the problems in the electrical network with isolated (compensated) neutral is the selective determination of the damaged element in a single-phase earth fault. For selective and reliable operation of protections against single-phase earth faults in networks with isolated (compensated) neutral, in addition to the zero-sequence current, information on phase voltages and zero-sequence voltage of the electrical network is required. Many transformer substations do not have traditional electromagnetic voltage transformers. For such substations, the problem of measuring high voltage can be solved by using capacitive dividers. A physical model was developed at the Department of Electric Power Engineering and Control Systems to test the operation of capacitive dividers designed to measure the voltages of 6 (10) kV bus sections. The scheme of the physical model used certified capacitive dividers used in voltage indication systems on bus sections with a voltage of 6 (10) kV. These capacitive dividers are developed by NPP RELSiS. A device has been developed for the operation of the voltage measurement circuit to match the signals supplied from the capacitive divider to the input of the digital recorder. To test the operation of capacitive dividers in the scheme of the physical model used a traditional electromagnetic voltage transformer type NTMI-10-66, From the secondary winding of which the voltage is fed to the digital recorder. The developed system in the basic operating modes is checked. A special program has been developed for the analysis of oscillograms recorded by a digital recorder. This program contains a number of functions for analyzing the coordinates of the mode, which allow you to perform harmonic analysis, calculate symmetrical components, form integral, differential characteristics and more. Using the Fourier transform, a digital model was developed that allows to obtain the effective values of the measured voltages and to distinguish their symmetrical components – zero and inverse sequences. Studies have shown that the measurement of high voltage using capacitive dividers can be used in circuits with devices for the operation of which requires control of phase voltages of the 6–10 kV network.

  1. Brzhezytsʹkyy V. O., Isakova A. V., Rudakov V. V. ta in. Tekhnika ta elektrofizyka vysokykh napruh: navch. posib. za red. V. O. Brzhezytsʹkoho ta V. M. Mykhaylova. Kharkiv: NTU “KHPI” Tornado, 2005. 926 s.
  2. Boyko N. I., Yevdoshenko L. S., Ivanov V. M., Khristenko O. A. Kompaktnyy yomkostnyy delitel' napryazheniya na 70 kV s ekranirovannym promezhutochnym elektrodom // Yelektrotekhníka í yelektromekhaníka. 2012, No. 6, S. 41– 46. DOI: https://doi.org/10.20998/2074-272X.2012.6.09.
  3. Wahlroos A., Altonen J. “Compensated networks and admittance based earth-fault protection”, seminar “Methods and techniques for earth fault detection, indication and location”, arranged by Kaunas University of Technology and Aalto University, 15th February, 2011. URL: https://library.e.abb.com/public/509d776e7bdcc425c1257847004468f4/ Compensared%20networks%20and%20admittance%20based%20earth%20fault%20protection_techpub_757370_EN a.pdf.
  4. Wahlroos A., Altonen J. et al. “Application of novel cumulative phasor sum measurement for earth-fault protection in compensated MV-networks”, 22nd International Conference on Electricity Distribution – CIRED, Stockholm, 10–13 June 2013. URL: http://sgemfinalreport.fi/files/CIRED2013_0607_paper.pdf.
  5. Indikator napryazheniya IN-10-1. Pasport. URL: https://relsis.ua/upload/in-10-1.pdf.
  6. Baran P. M., Kidyba V. P., Pryshlyak Ya. D., Shmahala  V. M. Prohramne zabezpechennya analizu informatsiyi z tsyfrovykh prystroyiv zakhystu ta avtomatyky // Visn. NU “Lʹvivsʹka politekhnika” “Elektroenerhetychni ta elektromekhanichni systemy”, 2003, No. 479, S. 10–17. URL: https://ena.lpnu.ua/handle/ntb/37667.
  7. Petro Baran, Yuriy Varetsky, Viktor Kidyba, Yaroslava Pryshliak, Іgor Sabadash, Oleksandr Franchuk. VPN- based monitoring power system facilitie: PRZEGLĄD ELEKTROTECHNICZNY, ISSN 0033-2097, R. 98 NR 5/2022. URL:   http://pe.org.pl/articles/2022/5/3.pdf.
  8. Fizychna modelʹ systemy telemekhaniky dlya operatyvno-dyspetchersʹkoho upravlinnya pidstantsiyamy /M. V. Bazylevych, P. M. Baran, V. P. Kidyba, H. M. Lysyak, I. O. Sabadash // Visnyk Natsionalʹnoho universytetu “Lʹvivsʹka politekhnika” “Elektroenerhetychni ta elektromekhanichni systemy”, 2017, No. 870, S. 3–8. URL: https://ena.lpnu.ua/handle/ntb/44877.