Effect of transformer on stochastic estimation of voltage sag due to faults in the power system: a PSCAD/EMTDC simulation

Voltage sags in the electric power system are mostly due to faults in the power system. Voltage sag is characterized by its magnitude (the retained voltage), phase-angle jump, unbalance in the sag in the three phases, and duration. Type of transformers in the electrical system is the important parameter influencing the characteristic of sag at the node where sensitive loads are connected. For sensitive loads it is necessary to estimate how many times in a year the voltage at their terminal will experience sag to avoid tripping of operation. In this paper the effect of transformer on stochastic estimation of voltage sag is studied. Several stochastic methods for the estimation of number of sags have been developed in recent years. Various methods of sag prediction require lengthy programming or calculations. In the present work the PSCAD/EMTDC software package is used to estimate number of sags assuming uniform distribution of faults along the lines.

Effect of transformer on stochastic estimation of voltage sag due to faults in the power system: a PSCAD/EMTDC simulation

Voltage sags in the electric power system are mostly due to faults in the power system. Voltage sag is characterized by its magnitude (the retained voltage), phase-angle jump, unbalance in the sag in the three phases, and duration. Type of transformers in the electrical system is the important parameter influencing the characteristic of sag at the node where sensitive loads are connected. For sensitive loads it is necessary to estimate how many times in a year the voltage at their terminal will experience sag to avoid tripping of operation. In this paper the effect of transformer on stochastic estimation of voltage sag is studied. Several stochastic methods for the estimation of number of sags have been developed in recent years. Various methods of sag prediction require lengthy programming or calculations. In the present work the PSCAD/EMTDC software package is used to estimate number of sags assuming uniform distribution of faults along the lines.

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  • Electric Power Research Institute, “An Assessment of Distribution System Power Quality.” TR-106294s-V1-3 Research Projects 3098-01. Palo Alto, Calif., 1996.
  • R. C. Dugan, M. F. McGranaghan, and H. W. Beaty, Electrical Power System Quality, New York, McGraw-Hill,1996. [3] M. H. J. Bollen, Understanding Power Quality Problems,Voltage Sags and interruptions, ser. IEEE Press Series on Power Engineering,Piscataway, NJ, 2000.
  • Elisa Espinosa Juarez , Araceli Hernandez, “An analytical approach for stochastic assessment of balanced and unbalanced voltage sags in large system,” IEEE Transaction on Power Delivery, Vol. 21, No. 3, pp. 1493–1500, July 2006.
  • Myo Thu Aung, Jovica V. Milanovic, “The influence of Transformer Winding Connection on the propogation of Voltage Sags”, IEEE Transaction on Power Delivery, Vol.21, No.1, pp. 262–269, January 2006
  • M. N. Moschakis, N. C. Hatziargyriou, “Analytical calculation and stochastic assessment of voltage sags”, IEEE Transaction on Power Delivery, Vol. 21, No., pp.1727–1734, July2006.
  • M. R. Quadar, M. H. J. Boolen, Ron N. Allan, “Stochastic Prediction of Voltage Sags in a Transmission System,” IEEE Transaction on Industrial Applications, Vol. 35, No. 1, pp.152–162, January/Februry 1999.
  • Elisa Espinosa Juarez , Araceli Hernandez, “ Stochastic Assessment of Phase-Angle Jump Caused by Voltage Sags Applying an Analytical Methos,” 9thInternational Conference PMAPS-2006, Sweden, June 2006.
  • M. H. J. Boolen, M. Speychal, K. Linden, “Estimation of Dip Frequency from Fault Stastaics-Including Three-Phase Characteristic,” 9thInternational Conference PMAPS-2006, Sweden, June 2006.
  • P. Heine, M. Lehtonen, “Probability of Voltage Sags Depending on the Characteristics of Mediuym Voltage Network,” 9thInternational Conference PMAPS-2006, Sweden, June 2006.
  • M. H. J.Boolen, G. Yalcinkaya, G.Hazza, “The use of Electromagnetic Transient Programs for Voltage Sag Analysis,” IEEE/PES and NTUA 8th International Conference ICHQP-98, Greece 1998.
  • M. H. J.Boolen, G. Yalcinkaya, J. Pellis, M. R. Quadar,” A Voltage Sag Study in a Large Industrial Distribution System,” 31th IEEE Industry Applications Conference[C], San Diego, USA, 1996.
  • J. A Martinez, J. Martin-Arnedo, “Voltage sag stochastic prediction using an electromagnetic transients program,” IEEE Transaction on Power Delivery, Vol. 19, No.4, pp. 1975–1982,October 2004
  • Monitoba HVDC Research Centre, “ PSCAD/EMTDC: Electromagnetic transients program including dc systems,” 1994
  • Ray Arnold, “Solutions to the Power Quality Problems,” Power Engineering Journal, pp. 65–73, April 2001.