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

The Korean Institute of Power Electronics (전력전자학회)
권호 표지
DOI QR코드

DOI QR Code

A Study for Mutual Interference of LCL Filter Under Parallel Operation of Grid-Connected Inverters

계통연계형 인버터 병렬운전 시 LCL 필터 상호간섭 특성 연구

  • Lee, Gang (Dept. of Electrical Engineering, Chungnam National University) ;
  • Seo, Joungjin (Dept. of Electrical Engineering, Chungnam National University) ;
  • Cha, Hanju (Dept. of Electrical Engineering, Chungnam National University)
  • Received : 2020.09.09
  • Accepted : 2020.12.29
  • Published : 2021.04.20
Download PDF
⟨ Previous Next ⟩

Abstract

This study analyzes the resonance characteristics caused by the mutual interference between LCL filters and the grid impedance under the parallel operation of the grid-connected inverter using the LCL filter. These characteristics are verified through simulation and experiment. Two inverters are used to connect to the grid in parallel, and the system parameters, including the LCL filter, are set to the same conditions. In the case of inverters running in parallel at the point of common coupling, the presence of grid impedance causes mutual interference between the LCL filters of each inverter, and the deviation of the filter resonance frequency is analyzed to understand the parallel inverter. The correlation between the number of devices and the size of grid impedance is simulated by PSIM and verified by MATLAB. By connecting the real-time digital simulator Typhoon HILS to the DSP 28377 control board, the mutual interference characteristics are tested under the condition of two inverters running in parallel. The experimental and analysis results are the same, indicating the validity of the analysis.

Keywords

References

  1. D. G. Holmes, T. A. Lipo, B. P. McGrath, and W. Y. Kong, "Optimized design of stationary frame three phase AC current regulators," IEEE Transactions on Power Electronics, Vol. 24, No. 11, pp. 2417-2416, Nov. 2009. https://doi.org/10.1109/TPEL.2009.2029548
  2. Y. Tang, W. Yao, P. C. Loh, and F. Blaabjerg, "Design of LCL filters with LCL resonance frequencies beyond nyquist frequency for grid-connected converters," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 4, No. 1, pp. 3-14, Mar. 2016. https://doi.org/10.1109/JESTPE.2015.2455042
  3. J. He, Y. W. Li, D. Bosnjak, and B. Harris, "Investigation and active damping of multiple resonances in a parallel-inverter-based microgrid," IEEE Transactions on Power Electronics, Vol. 28, No. 1, pp. 234-246, Jan. 2013. https://doi.org/10.1109/TPEL.2012.2195032
  4. M. Lu, X. Wang, P. C. Loh, and F. Blaabjerg, "Resonance interaction of multiparallel grid-connected inverters with LCL filter," IEEE Transactions on Power Electronics, Vol. 32, No. 2, pp. 894-899, Feb. 2017. https://doi.org/10.1109/TPEL.2016.2585547
  5. J. Jo, T. Lee, D. Yun, and H. Cha, "Analysis of current control stability using PI control in synchronous reference frame for grid-connected inverter with LCL filter," The Transactions of the Korean Institute of Power Electronics, Vol. 21, No. 2, pp. 168-174, Apr. 2016. https://doi.org/10.6113/TKPE.2016.21.2.168
  6. J. Jo "Analysis and design of stabilization techniques for distributed generation systems in microgrid," Department of Electrical Engineering Graduate School Chungnam National University, Chapter 5, pp. 94-104, Feb. 2020.
  7. J. Jo and H. Cha, "Design of effective passive damping resistor of grid-connected inverter with LCL filter for industrial applications," Journal of Electrical Engineering & Technology, Vol. 14, pp. 2039-2048, 2019. https://doi.org/10.1007/s42835-019-00239-1