Control of the Neutral Leg in Three-Phase Four-Wire Inverter Using Proportional-Resonant Controller

PR 제어기를 이용한 3상 4선식 인버터 Neutral Leg 제어 방법

  • Received : 2014.10.21
  • Accepted : 2014.12.17
  • Published : 2015.02.28


In 3-phase 4-wire inverter, the unbalanced loads cause to increase the neutral current which brings the voltage deviation between the split dc-link capacitors to be larger. In order to solve this problem, a neutral leg is provided additively to the ordinary inverter circuit and the associated control methods are devised. This paper proposes a new neutral-leg controller based on a PR controller and shows relatively good performance even under unbalanced linear loads and nonlinear loads. The proposed control strategy illustrates its effectiveness under the various operating conditions through simulation works.


Three-Phase Four-Wire Inverter;Dc-Link Balancing Control;Proportional-Resonant Control


  1. Y. B. Byun, S. J. Park, Y. B. Choo, S. J. Kwon and C. U. Kim, "A Study on the Distortion Reducing of Output Voltage for UPS by Estimated Load Current," Transactions of KIEE, vol. 12, no. 1, pp. 69-77, 1998.
  2. H. M. Yun, J. Y. Bae and Y. Kim, "The Inverter Control Method Using The Voltage Sag Compensation algorithm," Transactions of KIEE, vol. 26, no. 12, pp. 62-67, 2012.
  3. Q. C. Zhong, L. Hobson and M. G. Jayne, "Classical Control of the Neutral Point in 4-wire 3-phase DC-AC Converters," Electrical Power Quality and Utilisation Journal, vol. 11, no. 2, pp. 111-119, 2005.
  4. Q. C. Zhong, J. Liang, G. Weiss, C. Feng, and T. C. Green, "$H{\infty}$ Control of the Neutral Point in Four-Wire Three-Phase DC-AC Converters," IEEE Transactions on Industrial Electronics, vol. 53, no. 5, pp. 1594-1602, 2006.
  5. T. Hornik, Q. C. Zhong, "Parallel PI Voltage-$H{\infty}$ Current Controller for the Neutral Point of a Three-Phase Inverter," IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1335-1343, 2013.
  6. W. C. Lee, "Maximum Power Point Tracking Control for a Grid-Tie Photovoltaic Inverter," Transactions of KIEE, vol. 23, no. 5, pp. 72-79, 2009.
  7. S. H. Han, J. H. Park, H. G. Kim, H. N. Cha, T. W. Chun and E. C. Nho, "Dead Time Compensation of Grid-connected Inverter Using Resonant Controller," Transactions of KIPE, vol. 16, no. 6, pp. 569-576, 2011.
  8. J. H. Park, T. H. Jo, H. G. Kim, T. W. Chun, E. C. Nho and H. N. Cha, "Comparison of Current Controllers of Grid-connected PCS for Distributed Resources," Transactions of KIPE, vol. 17, no. 3, pp. 274-280, 2012.
  9. T. H. Nguten, D. C. Lee and S. G. Lee, "Sinusoidal Current Control of Single-Phase PWM Converters under Voltage Source Distortion Using Composite Observer," Transactions of KIPE, vol. 16, no. 5, pp. 466-476, 2011.


Supported by : 서울과학기술대학교