Method to Estimate Expected Sag Frequency Considering the Operating Condition of Power System

전력계통 운전조건을 고려한 순간전압강하 추계 방법

Son, Jeongdae;Lee, Kyebyung;Park, Chang-Hyun

  • Received : 2015.12.14
  • Accepted : 2016.02.05
  • Published : 2016.03.01


This paper deals with the assessment of voltage sags regarding the variation of system operating conditions. In general, voltage sag assessment is performed by assuming the constant operating condition throughout the year. However, the assumption can lead to assessment errors in case of considerable changes of system operation condition. This paper presents a method to estimate ESF(expected sag frequency) considering the operating conditions according to the changes of power demand throughout the year.


Area of vulnerability;Load factor;Operating condition;Power quality;Voltage sag assessment


  1. M. H. J. Bollen, Understanding Power Quality Problems: Voltage Sags and Interruptions, Piscataway, NJ, 2000, IEEE Power Engineering Series.
  2. R. C. Dugan, M. F. McGranaghan, S. Santoso, and H. W. Beaty, Electrical Power Systems Quality. New York: McGraw-Hill, 2002, ch. 3.
  3. M. H. J. Bollen, "Fast assessment methods for voltage sags in distribution systems," IEEE Trans. Ind. Appl., Vol. 32, No. 6, pp. 1414-1423, Nov./Dec. 1996.
  4. M. R. Qader, M. H. J. Bollen, and R. N. Allan, "Stochastic prediction of voltage sags in a large transmission system", IEEE Trans. Ind. Appl., Vol. 35, No. 1, pp. 152-162, 1999.
  5. J. Wang, S. Chen, and T. T. Lie, "System voltage sag performance estimation," IEEE Trans. Power Deliv., Vol. 20, No. 2, pp. 1738-1747, Apr. 2005.
  6. C. H. Park and G. Jang, "Stochastic Estimation of Voltage Sags in a Large Meshed Network," IEEE Trans. Power Del., Vol. 22, No. 3, pp. 1655-1664, 2007.
  7. C. H. Park, J. H. Hong, and G. Jang, "Assessment of system voltage sag performance based on the concept of area of severity", IET Gener. Transm. Distrib., Vol. 4, No. 6, pp. 683-693, 2010.
  8. C. H. Park, G. Jang and R. J. Thomas, "The influence of generator scheduling and time-varying fault rates on voltage sag prediction," IEEE Trans. Power Del., Vol. 23, No. 2, pp. 1243-1250, Apr. 2008.
  9. KPX, "Operating Performance of Electricity Market 2014. 10", 2014.11.
  10. C. H. Park, "Development of a Method to Analyze Voltage Sag Monitoring Data", Journal of KIIEE,, Vol. 27, No. 4, pp. 16-22, April 2013.
  11. IEEE 57-Bus Test Case, [Online]. Available:


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