An Integrated Compensation Algorithm for PCC Voltage Fluctuation and Unbalance with Variable Limit of Positive and Negative Sequence Currents

  • Im, Ji-Hoon (Energy New Business Laboratory, KEPCO Research Institute) ;
  • Song, Seung-Ho (Dept. of Electrical Engineering, Kwangwoon University) ;
  • Cho, Sung-Min (Energy New Business Laboratory, KEPCO Research Institute)
  • Received : 2015.12.31
  • Accepted : 2016.12.12
  • Published : 2017.03.01


This paper proposes a point of common coupling (PCC) voltage compensation algorithm using a current limitation strategy for use in distributed generation (DG). The proposed strategy maintains the PCC voltage by prioritizing currents when an output current reference is larger than the current capacity of the power condition system (PCS) of the DG. With this strategy, the DG outputs the active current, reactive current, and the negative sequence current. The DG uses the reactive current for maintaining the PCC voltage within a normal range; the negative sequence current is used for reducing the PCC voltage unbalance. The proposed method was verified using PSIM simulation and experimental results.


Distributed generation;Unbalanced voltage conditions;Dual current control;Positive sequence;Negative sequence;Current limitation


Supported by : Korea Institute of Energy Technology Evaluation and Planning (KETEP)


  1. Y. Hu, Z. Chen, P. Excell, "Power quality improvement of unbalanced power system with distributed generation units," DPRT 2011 4th International Conference, pp. 417-423, July. 2011.
  2. M. Davari, A. R. Pourshoghi, I. Salabeigi, G. B. Gharegpetian, S. G. Fathi, "A new nonlinear controller design using average state space model of the inverter based distributed generation to mitigate power quality problems," ICEMS 2009 International Conference, pp. 1-5, Nov. 2009.
  3. P. R. Khatri, V. S. Jape, N. M. Lokhande, B. S. Motling, "Improving power quality by distributed generation," IPEC 2005 7th International Conference, vol. 2, pp. 675-678, Dec. 2005.
  4. C. L. Su, "Comparative analysis of voltage control strategies in distribution networks with distributed generation," 2009 IEEE PES, pp. 1-7, Jul. 2009.
  5. J. H. Im, S. Kang, S. H. Song, S. K. Jeong, J. Y. Choi, I. Choy, "Reactive power control strategy for inverterbased distributed generation system with a programable limit of the voltage variation at PCC," 2011 ICPE, page. 2979-2984. 2011
  6. Sean Zilberdrut, Valentina Cecchi, "Investigating the Effects of Grid Equivalent Circuit at a Point of Common Coupling on Bus Voltage Variations due to Variable Distributed Generation," North American Power Symposium 2015, Oct. 2015
  7. J. H. Im, S, H. Song, "Simplified Wind Turbine Modeling and Calculation of PCC Voltage Variattion according to Grid Connection Conditions," Trans. KIEE, vol. 58. no.12, Dec. 2009.
  8. Volker Diedrichs, Alfred Beekmann and Stephan Adloff, "Loss of (Angle) Stability of Wind Power Plants - The Underestimated Phenomenon in Case of Very Low Short Circuit Ratio-," 12nd International Workshop on Large Scale Integration of Wind Power, 2013.
  9. IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems, IEEE Std. 1547.2-2008, 2008.
  10. Minnan Wang, Jin Zhong, "A novel method of distributed generation and capacitor optimal placement considering voltage profiles," 2011 IEEE PES General Meeting, pp. 1-6, Jul. 2011.
  11. Fadaeinedjad R., Moschopoulos G., Moallem M, "Using STATCOM to mitigate voltage fluctuations due to aerodynamic aspects of wind turbines," 2008 IEEE PESC, pp. 3648-3654, Jun. 2008.
  12. Tzung Lin Lee, Shang Hung Hu, Yu Hung Chan, "DSTATCOM with positive sequence admittance and negative sequence conductance to mitigate voltage fluctuations in high level penetration of distributed generation systems," IEEE Trans. on Industrial Electronics, vol. 60, no.4, pp. 1417-1428, Apr. 2013.
  13. S. H. Song, J. H. Im, E. H. Kim, "Measurement and analysis of PCC voltage variation in a wind diesel hybrid system - a case study in Sapsi island," 2009 EPE Wind Energy Chapter 2nd Seminar, Apr. 2009.
  14. J. H. Im, S. H. Song, S. Kang, "Analysis and Compensation of PCC Voltage Variations caused by Wind Turbine Power Fluctuations," JPE, vol. 13, no. 5, pp. 854-860, 2013.
  15. B. C. Jeong, S. H. Song, "Torque ripple compensation using negative sequence current control during unbalanced grid conditions in a DFIG system," INTELEC 2009, Jan, 2009
  16. Annette von Jouanne, Basudeb Ben Banerjee, "Assessment of Voltage Unbalance," IEEE Trans. on Power Delivery, vol. 16, no.4, pp. 1-7, Jul. 2009.
  17. Nicholas P.W. Strachan, Dragan Jovcic, "Stability of a Variable Speed Permanent Magnet Wind Generator with Weak AC Grids," IEEE Trans. on Power Delivery, vol. 25, no.4, Oct. 2010.