Compensation Algorithm for a Measurement Voltage Transformer

측정용 전압 변성기 오차 보상 알고리즘

  • 강용철 (전북대 대학원 전기공학과) ;
  • 박종민 (전북대 대학원 전기공학과) ;
  • 이미선 (전북대 대학원 전기공학과) ;
  • 장성일 (전북대 대학원 전기공학과) ;
  • 김용균 (한국IED Eng.)
  • Published : 2008.05.01

Abstract

This paper describes a compensation algorithm for a measurement voltage transformer (VT) based on the hysteresis characteristics of the core. The error of the VT is caused by the voltages across the primary and secondary windings. The latter depends on the secondary current whilst the former depends on the primary current, i.e. the sum of the exciting current and the secondary current. The proposed algorithm calculates the voltages across the primary and secondary windings and add them to the measured secondary voltage for compensation. To do this, the primary and secondary currents should be estimated. The secondary current is obtained directly from the secondary voltage and used to calculate the voltage across the secondary winding. For the primary current, in this paper, the exciting current is decomposed into the two currents, i.e. the core-loss current and the magnetizing current. The core-loss current is obtained by dividing the primary induced voltage by the core-loss resistance. The magnetizing current is obtained by inserting the flux into the flux-magnetizing current curve. The calculated voltages across the primary and secondary windings are added to the measured secondary current for compensation. The proposed compensation algorithm improves the error of the VT significantly.

Keywords

Voltage transformer;Compensation algorithm;Hysteresis characteristics and Iron core

References

  1. D. Slomovitz, "Electronic compensation of voltage transformer" IEEE Trans. Instrum. Meas., vol. 37, Dec. 1988 pp. 652-654 https://doi.org/10.1109/19.9832
  2. KS C IEC 60044-1 or 7: 2003
  3. D. Slomovitz, "Electronic Based High-Voltage Measuring Transformer" IEEE Trans. Power delivery. vol. 17, No. 2, April. 2002 pp. 359-361 https://doi.org/10.1109/61.997899
  4. 강용철, 소순홍, 정태영, 장성일, 김용균, "히스테리시스 특성을 고려한 측정용 변류기 2차 전류 보상 알고리즘", 전기학회 논문지. vol. 55, No. 10, 10. 2007 pp. 1709-1714