전력전자학회논문지 (The Transactions of the Korean Institute of Power Electronics)

  • 제20권6호
  • /
  • Pages.526-533
  • /
  • 2015
  • /
  • 1229-2214(pISSN)
  • /
  • 2288-6281(eISSN)
전력전자학회 (The Korean Institute of Power Electronics)
권호 표지
DOI QR코드

DOI QR Code

3상 계통 연계형 인버터의 역상분 전류 주입을 이용한 계통 등가 임피던스 추정 기법

Equivalent Grid Impedance Estimation Method Using Negative Sequence Current Injection in Three-Phase Grid-connected Inverter

  • 투고 : 2015.06.30
  • 심사 : 2015.10.20
  • 발행 : 2015.12.20
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

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.

키워드

참고문헌

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. A. V. Timbus, "Line impedance estimation using active and reactive power variations," Power Electronics Specialists Conference, 2007. IEEE, pp. 1273-1279, Jun. 2007.
  8. 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.
  9. 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. https://doi.org/10.1109/41.793344
  10. 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.
  11. P. M. Anderson, "Symmetrical components, in analysis of faulted power systems," Piscataway, NJ:IEEE Press, 1995.
  12. P. Pillary and M. Manyage, “Definitions of voltage unbalance,” IEEE Power Eng. Rev., Vol. 21, No. 5, pp. 50-51, May. 2001.