Advanced SearchSearch Tips
Equivalent Grid Impedance Estimation Method Using Negative Sequence Current Injection in Three-Phase Grid-connected Inverter
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Equivalent Grid Impedance Estimation Method Using Negative Sequence Current Injection in Three-Phase Grid-connected Inverter
Park, Chan-Sol; Song, Seung-Ho; Im, Ji-Hoon;
  PDF(new window)
A new algorithm is proposed for the estimation of equivalent grid impedance at the point of common coupling of a grid-tie inverter output. The estimated impedance parameter can be used for the improvement of the performance and the stability of the distributed generation system. The estimation error is inevitable in the conventional estimation method because of the axis rotation due to PLL. In the conventional estimation error, the d-q voltage and current are used for the calculation of the impedance with active and reactive current injections. Conversely, in the proposed algorithm, the negative sequence current is injected, and then the negative sequence voltage is measured for the impedance estimation. As the positive and negative sequence current controller is independent and the PLL is based on the positive sequence component only, the estimation of the equivalent impedance can be achieved with high accuracy. Simulation and experimental results are compared to validate the proposed algorithm.
Grid impedance estimation;Equivalent grid impedance;Negative sequence current injection;Grid-connected inverter;Unbalanced voltage;
 Cited by
D. G. Choi, W. J. Choi, S. W. Choi, and G. B. Lee, "Gain-scheduling method for grid-connected inverters using grid-impedance estimation," 2015 Power Electronics Annual Conference, pp. 612-614, Jul. 2009.

M. Liserre, "Stability of grid-connected PV inverters with large grid impedance variation," Power Electronics Specialists Conference, 2004 IEEE 35th Annual, Vol. 6, pp. 4773-4779, Jun. 2004.

J. H. Im and S. H. Song, "Simplified wind turbine modeling and calculation of PCC voltage variation according t-o grid connection conditions," The Trans. on The Korean Institute of Electrical Engineers, Vol. 58, No. 12, pp. 2402-2409, Dec. 2009.

J. H. Im and S. H. Song, "Compensation of PCC voltage variation by injection of required reactive power in a grid connected distributed source," Korean Solar Energy Society Conference, pp. 79-84, Nov. 2010.

M. Ciobotaru, "On-line grid impedance estimation based on harmonic injection for grid-connected PV inverter," Industrial Electronics, ISIE 2007. IEEE International Symposium, pp. 2437-2442, Jun. 2007.

M. Ciobotaru, "Online grid impedance estimation for single-phase grid-connected systems using PQ variations," Power Electronics Specialists Conference, 2007. IEEE, pp. 2306-2312, Jun. 2007.

A. V. Timbus, "Line impedance estimation using active and reactive power variations," Power Electronics Specialists Conference, 2007. IEEE, pp. 1273-1279, Jun. 2007.

J. H. Jo and R. Y. Kim, “An improved grid impedance estimation using PQ variations,” Jounal of Power Electronics, Vol. 20, No. 2, pp. 152-159, Apr. 2015.

H. S. Song and K. Nam, "Dual current control scheme for PWM converter under unbalanced input voltage conditions," IEEE Trans. Ind. Electron, Vol. 46, No. 5, pp. 953-959. Oct. 1999. crossref(new window)

S. J. Lee and S. K. Sul, "A new phase detection method for power conversion systems considering distored conditions in power system," in proc. IEEE-IAS Annu. Meeting, Vol. 4, pp. 2167-2172, 1999.

P. M. Anderson, "Symmetrical components, in analysis of faulted power systems," Piscataway, NJ:IEEE Press, 1995.

P. Pillary and M. Manyage, “Definitions of voltage unbalance,” IEEE Power Eng. Rev., Vol. 21, No. 5, pp. 50-51, May. 2001.