- Volume 15 Issue 5
DOI QR Code
DC Injection Control for Grid-Connected Single-Phase Inverters Based on Virtual Capacitor
- Wang, Wei ;
- Wang, Ping ;
- Bei, Taizhou ;
- Cai, Mengmeng
- Received : 2014.08.18
- Accepted : 2015.04.05
- Published : 2015.09.20
DC injection is a critical issue in transformerless grid-connected inverters. DC injection control based on virtual capacitor has the advantages of low cost, low loss, high accuracy and easy implementation. In this paper, the principle of DC injection control based on virtual capacitor was analyzed. In addition, the applicable conditions, working process, steady state error and advantages were also discussed in detail. The design of the control parameters based on virtual capacitor was proposed in a grid-connected inverter with LCL filter. The robustness of the control parameters was also discussed. Simulation and experimental results verify the validity of the analysis and demonstrate that this research has a certain value in engineering applications.
DC injection control;Design of parameters;LCL filter;Robustness;Virtual capacitor
- R. Sharma, “Removal of DC offset current from transformerless PV inverters connected to utility,” in 40th International Universities Power Engineering Conference, pp. 1230-1234, 2005.
- L. Bowtell and A. Ahfock, “Direct current offset controller for transformerless single-phase photovoltaic grid-connected inverters,” IET Renewable Power Generation, Vol. 4, No. 5, pp. 428-437, Sep. 2010. https://doi.org/10.1049/iet-rpg.2009.0043
- G. Buticchi, G. Franceschini, E. Lorenzani, C. Tassoni, and A. Bellini, “A novel current sensing DC offset compensation strategy in transformerless grid connected power converters,” in Energy Conversion Congress and Exposition, pp. 3889-3894, 2009.
- G.-Q. Shen, X.-C. Zhu, J. Zhang, and D.-H. Xu, “A new feedback method for PR current control of LCL-filter-based grid-connected inverter,” IEEE Trans. Ind. Electron., Vol. 57, No. 6, pp. 2033-2041, Jun. 2010. https://doi.org/10.1109/TIE.2010.2040552
- M. Liserre, R. Teodorescu, and F. Blaabjerg, “Stability of photovoltaic and wind turbine grid-connected inverters for a large set of grid impedance values,” IEEE Trans. Power Electron., Vol. 21, No. 1, pp. 263-272, Jan. 2006. https://doi.org/10.1109/TPEL.2005.861185
- X.-Q. Guo, W.-Y. Wu, H.-R. Gu, and G.-C. San, "DC injection control for grid-connected inverters based on virtual capacitor concept," in International Conference on Electrical Machines and System, pp. 2327-2330, 2008.
- B.-C. Wang, X.-Q. Guo, Q. Mei, X.-F. Sun, and W.-Y. Wu, "DC injection control for transformerless PV grid-connected inverters," in Proc. the Chinese Society for Electrical Engineering, Vol. 29, No. 36, pp. 23-28, Dec. 2009.
- V. Salas, E. Olías, M. Alonso, F. Chenlo, and A. Barrado, “DC current injection into the network from PV grid inverter,” in Conference Record of the 2006 4th World Conference on Photovoltaic Energy Conversion, pp. 2371-2374,2006.
- M. Armstrong, D. J. Atkinson, C. M. Johnson, and T. D. Abeyasekera, “Auto-Calibrating DC link current sensing technique for transformerless, grid connected, H-bridge inverter systems,” IEEE Trans. Power Electron., Vol. 21, No. 5, pp. 1385-1393, Sep. 2006. https://doi.org/10.1109/TPEL.2006.880267
- L. Zhou, B. Yang, K. Guo, H.-X. Li, and Z.-M. Zhang, “The progress and development trend of the DC injection issue in PV grid-connected systems,” Power System Protection and Control, Vol. 40, No. 6, pp. 147-155, Mar. 2012.
- R. González, J. López, P. Sanchis, and L. Marroyo, “Transformerless inverter for single-phase photovoltaic systems,” IEEE Trans. Power Electron., Vol. 22, No. 2, pp. 693-697, Mar. 2007. https://doi.org/10.1109/TPEL.2007.892120
- O. Lopez, R. Teodorescu, F. Freijedo, and J.D. Gandoy, “Leakage current evaluation of a single-phase transformerless PV inverter connected to the grid,” in Applied Power Electronics Conference, pp. 907-912, 2007.