Comparator effect on equivalence of results of calibrating current transformers

Authors

  • Valentyn Isaiev State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143, Ukraine https://orcid.org/0000-0001-6763-9392
  • Oleh Velychko State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143, Ukraine https://orcid.org/0000-0002-6564-4144
  • Yurii Anokhin State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143, Ukraine https://orcid.org/0000-0003-1213-739X

DOI:

https://doi.org/10.15587/1729-4061.2019.177415

Keywords:

equivalence, measurement, comparator, current transformer, standard, ratio error, phase displacement, uncertainty

Abstract

Many different high-precision systems for determining the ratio error and phase displacement of current transformers have been developed by leading specialists in the world. The latest research solutions with the use of the latest measurement tools, instantaneous sampling techniques, and analysis of sources of uncertainty have been applied in these developments. The objective difficulty is that only a limited number of specialized institutes implement such projects with the involvement of leading experts in the field of measurement and significant funds. First of all, these are the national metrological institutes of countries with high economic opportunities. At the level of conventional calibration laboratories equipped with modern facilities and highly qualified personnel, the uncertainty of measurements increases 10 times or more when calibrating precision instrument transformers. Thus, it has not been investigated to what extent the readouts of commercial comparators of different manufacturers in the calibration of instrument transformers of class 0.2S and more precise are equivalent. Determination of the equivalence level of AC comparators of different types in the day-to-day calibration of current transformers is the main objective of this research. More than 50 comparators of different types (with inductive or resistive current transducers) were investigated relative to 2 well-characterized reference current transformers. Comparison of the results obtained by two instruments with radically different principles of measurement gave a difference of 23 μA/A in ratio error and 52 μrad in phase displacement. The results of estimating the readout stability of modern comparators of serial production are also highlighted. The results of the analysis of the data obtained allow us to assume that measurement results of ratio error of about 50 μA/A have equivalence level within ±20 μA/A. The measurement results of phase displacement of about 50 μrad have equivalence level within ±15 μrad. Concerning the determination of metrological characteristics of current transformers with accuracy class 0.2S, their equivalence must be considered taking into account all exploited comparators. The results cause the question about the adequacy of the accuracy margin of the current transformer in the production to overlap the difference in the readouts of 260 μA/A and 500 μrad

Author Biographies

Valentyn Isaiev, State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143

Senior Researcher

Research and Development Department of Measurement of Electric Quantities

Oleh Velychko, State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143

Doctor of Technical Sciences, Professor, Director

Scientific and Production Institute of Electromagnetic Measurements

Yurii Anokhin, State Enterprise “All-Ukrainian State Scientific and Production Centre for Standardization, Metrology, Certification and Protection of Consumer”, (SE “Ukrmetrteststandard”) Metrolohychna str., 4, Kyiv, Ukraine, 03143

Head of Department

Research and Development Department of Measurement of Electric Quantities

References

  1. IEC 61869-1:2007. Instrument transformers – Part 1: General requirements. Available at: https://webstore.iec.ch/publication/6047
  2. Faifer, M., Ottoboni, R., Toscani, S., Cherbaucich, C., Gentili, M., Mazza, P. (2013). A medium voltage signal generator for the testing of voltage measurement transducers. 2013 IEEE International Instrumentation and Measurement Technology Conference (I2MTC). doi: https://doi.org/10.1109/i2mtc.2013.6555408
  3. Palani, A., Santhi, S., Gopalakrishna, S., Jayashankar, V. (2008). Real-Time Techniques to Measure Winding Displacement in Transformers During Short-Circuit Tests. IEEE Transactions on Power Delivery, 23 (2), 726–732. doi: https://doi.org/10.1109/tpwrd.2007.911110
  4. Mohns, E., Roeissle, G., Fricke, S., Pauling, F. (2017). An AC Current Transformer Standard Measuring System for Power Frequencies. IEEE Transactions on Instrumentation and Measurement, 66 (6), 1433–1440. doi: https://doi.org/10.1109/tim.2017.2648918
  5. Isaiev, V. (2018). Finding reference values to calibrate two alternating currents comparator. World Science, 1 (2 (30)), 57–61.
  6. Iwanusiw, O. W., Eng, P. (2018). The Art and Science of Transformer Ratio Measurement. 2018 IEEE Electrical Insulation Conference (EIC). doi: https://doi.org/10.1109/eic.2018.8481036
  7. Mahesh, G., George, B., Jayashankar, V., Kumar, V. J. (2004). Instrument transformer performance under distorted-conditions. Proceedings of the IEEE INDICON 2004. First India Annual Conference, 2004. doi: https://doi.org/10.1109/indico.2004.1497797
  8. Iwanusiw, O. W. (1983). Microprocessor-Based Automatic Instrument Transformer Comparator. IEEE Transactions on Instrumentation and Measurement, 32 (1), 165–169. doi: https://doi.org/10.1109/tim.1983.4315033
  9. Jagadeesh Kumar, V., Sunil, C., Sankaran, P. (2001). PC-based method for the measurement of instrument transformer errors. 11th IMEKO TC-4 Symposium. Trends in Electrical Measurement and Instrumentation, 74–77.
  10. Mohan, N. M., George, B., Kumar, V. J. (2006). Virtual Instrument for Testing of Current and Voltage Transformers. 2006 IEEE Instrumentation and Measurement Technology Conference Proceedings. doi: https://doi.org/10.1109/imtc.2006.328442
  11. Wang, Y., Liu, T., Hu, X. (2012). Study of current transformer calibrating system based on equivalent model. IEEE 10th International Conference on Industrial Informatics. doi: https://doi.org/10.1109/indin.2012.6301129
  12. Yang, T., Zhang, G., Hu, X. (2013). System design of current transformer accuracy tester based on ARM. 2013 IEEE 8th Conference on Industrial Electronics and Applications (ICIEA). doi: https://doi.org/10.1109/iciea.2013.6566445
  13. George, N., Ooka, P. V., Gopalakrishna, S. (2018). An Efficient Digitizer for Calibration of Instrument Transformers. 2018 IEEE 9th International Workshop on Applied Measurements for Power Systems (AMPS). doi: https://doi.org/10.1109/amps.2018.8494842
  14. Brandolini, A., Faifer, M., Ottoboni, R. (2009). A Simple Method for the Calibration of Traditional and Electronic Measurement Current and Voltage Transformers. IEEE Transactions on Instrumentation and Measurement, 58 (5), 1345–1353. doi: https://doi.org/10.1109/tim.2008.2009184
  15. Harmon, S., Henderson, L. (2009). Final report EUROMET.EM-S11 on EUROMET Projects 473 and 612: Comparison of the measurement of current transformers (CTs). Metrologia, 46 (1A), 01005–01005. doi: https://doi.org/10.1088/0026-1394/46/1a/01005
  16. Isaiev, V. (2018). Method of reference values defining for calibration of two alternating currents comparator with using oscilloscope. World Science, 2 (4 (32)), 42–49. Available at: http://archive.ws-conference.com/wp-content/uploads/2323.pdf
  17. IEC 61869-2:2012. Instrument transformers – Part 2: Additional requirements for current transformers. Available at: https://webstore.iec.ch/publication/6050
  18. CT Analyzer User Manual (2008). Omicron Electronics GmbH, 240. Available at: http://userequip.com/files/specs/6031/CT-Analyzer_user%20manual.pdf

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Published

2019-09-04

How to Cite

Isaiev, V., Velychko, O., & Anokhin, Y. (2019). Comparator effect on equivalence of results of calibrating current transformers. Eastern-European Journal of Enterprise Technologies, 5(5 (101), 6–15. https://doi.org/10.15587/1729-4061.2019.177415

Issue

Section

Applied physics