A Novel Neutral Point Clamped Full-Bridge Topology for Transformerless Photovoltaic Grid-Connected Inverters
Abstract
This paper presents a novel neutral point clamped full-bridge topology for transformerless photovoltaic grid-tied inverters. Transformerless grid-connected inverters have been used widely in recent years since they offer higher efficiency and lower costs. Ground leakage current suppression is the main issue which should be considered carefully in transformerless photovoltaic grid-connected inverters. Among different methods used to decline ground leakage current, neutral point clamped (NPC) topologies are considered more useful and effective. In NPC topologies, the short-circuited output voltage at the freewheeling period is clamped to the middle of the DC bus voltage. Therefore, the common-mode voltage (CM) will be constant at the whole switching period. Various NPC topologies such as H6 [1], HB-ZVR [2], oH5 [3], and PN-NPC [4] have been proposed. In this paper, a novel NPC topology is proposed which has lower power losses and higher efficiency over previous topologies. Furthermore, the proposed NPC topology exhibits a similar ground leakage current with the PN-NPC topology. The proposed NPC topology is analyzed theoretically using simulation studies and an experimental prototype is provided to verify theoretical analysis and simulation studies.
Keywords:
common-mode voltage (CMV), grid-connected inverter, ground leakage current, neutral point clamped (NPC) topology, photovoltaic (PV) generation systemDownloads
References
R. Gonzalez, J. Lopez, P. Sanchis, L. Marroyo, “Transformerless inverter for single-phase photovoltaic systems”, IEEE Transactions on Power Electronics, Vol. 22, No. 10, pp. 693-697, 2007 DOI: https://doi.org/10.1109/TPEL.2007.892120
T. Kerekes, R. Teodorescu, P. Rodríguez, G. Vázquez, E. Aldabas, “A new high-efficiency single-phase transformerless PV inverter topology”, IEEE Transactions on Industrial Electronics, Vol. 58, No. 1, pp. 184-191, 2011 DOI: https://doi.org/10.1109/TIE.2009.2024092
H. Xiao, S. Xie, Y. Chen, R. Huang, “An optimized transformerless photovoltaic grid-connected inverter”, IEEE Transactions on Industrial Electronics, Vol. 58, No. 5, pp. 1887-1895, 2011 DOI: https://doi.org/10.1109/TIE.2010.2054056
L. Zhang, K. Sun, L. Feng, H. Wu, Y. Xing, “A family of neutral point clamped full-bridge topologies for transformerless photovoltaic grid-tied inverters”, IEEE Transactions on Power Electronics, Vol. 28, No. 2, pp. 730-739, 2013 DOI: https://doi.org/10.1109/TPEL.2012.2205406
D. Barater, E. Lorenzani, C. Concari, G. Franceschini, G. Buticchi, “Recent advances in single-phase transformerless photovoltaic inverters”, IET Renewable Power Generation, Vol. 10, No. 2, pp. 260-273, 2016 DOI: https://doi.org/10.1049/iet-rpg.2015.0101
M. Islam, S. Mekhilef, M. Hasan, “Single phase transformerless inverter topologies for grid-tied photovoltaic system: a review”, Renewable and Sustainable Energy Reviews, Vol. 45, pp. 69-86, 2015 DOI: https://doi.org/10.1016/j.rser.2015.01.009
M. Victor, F. Greizer, S. Bremicker, U. Hübler, “Method of converting a direct current voltage from a source of direct current voltage, more specifically from a photovoltaic source of direct current voltage, into a alternating current voltage”, U.S. Patent 7,411,802, 2008
S. Christoph, K. Jurgen, “Inverter for transforming a DC voltage into an AC current or an AC voltage”, Europe Patent 1, No. 369, p. 985, 2003
W. Yu, J. S. J. Lai, H. Qian, C. Hutchens, “High-efficiency MOSFET inverter with H6-type configuration for photovoltaic nonisolated AC-module applications”, IEEE Transactions on Power Electronics, Vol. 26, No. 4, pp. 1253-1260, 2011 DOI: https://doi.org/10.1109/TPEL.2010.2071402
B. Yang, W. Li, Y. Gu, W. Cui, X. He, “Improved transformerless inverter with common-mode leakage current elimination for a photovoltaic grid-connected power system”, IEEE Transactions on Power Electronics, Vol. 27, No. 2, pp. 752-762, 2012 DOI: https://doi.org/10.1109/TPEL.2011.2160359
B. Gu, J. Dominic, J. S. Lai, C. L. Chen, T. LaBella, B. Chen, “High reliability and efficiency single-phase transformerless inverter for grid-connected photovoltaic systems”, IEEE Transactions on Power Electronics, Vol. 28, No. 5, pp. 2235-2245, 2013 DOI: https://doi.org/10.1109/TPEL.2012.2214237
S. Bremicker, F. Greizer, M. Victor, “Inverter, more specifically for photovoltaic plants”, U.S. Patent 7.843,714, 2010
M. Xu, L. Zhang, Y. Xing, L. Feng, “A novel H6-type transformerless inverter for grid-connected photovoltaic application”, 7th IEEE Conference on Industrial Electronics and Applications (ICIEA), pp. 58-63, 2012 DOI: https://doi.org/10.1109/ICIEA.2012.6360697
J. Wang, B. Ji, J. Zhao, J. Yu, “From H4, H5 to H6—Standardization of full-bridge single phase photovoltaic inverter topologies without ground leakage current issue”, IEEE Energy Conversion Congress and Exposition (ECCE), pp. 2419-2425, 2012 DOI: https://doi.org/10.1109/ECCE.2012.6342552
J. M. Shen, H. L. Jou, J. C. Wu, “Novel transformerless grid-connected power converter with negative grounding for photovoltaic generation system», IEEE Transactions on Power Electronics, Vol. 27, No. 4, pp. 1818-1829, 2012 DOI: https://doi.org/10.1109/TPEL.2011.2170435
D. Dong, F. Luo, D. Boroyevich, P. Mattavelli, “Leakage current reduction in a single-phase bidirectional AC–DC full-bridge inverter”, IEEE Transactions on Power Electronics, Vol. 27, No. 10, pp. 4281-4291, 2012 DOI: https://doi.org/10.1109/TPEL.2012.2190300
L. Zhang, K. Sun, Y. Xing, M. Xing, “H6 transformerless full-bridge PV grid-tied inverters”, IEEE Transactions on Power Electronics, Vol. 29, No. 3, pp. 1229-1238, 2014 DOI: https://doi.org/10.1109/TPEL.2013.2260178
W. Cui, B. Yang, Y. Zhao, W. Li, X. He, “A novel single-phase transformerless grid-connected inverter”, 37th Annual Conference on IEEE Industrial Electronics Society, pp. 1126-1130, 2011
S. V. Araujo, P. Zacharias, B. Sahan, “Novel grid-connected non-isolated converters for photovoltaic systems with grounded generator», IEEE Power Electronics Specialists Conference, pp. 58-65, June, 2008 DOI: https://doi.org/10.1109/PESC.2008.4591897
Downloads
How to Cite
License
Authors who publish with this journal agree to the following terms:
- Authors retain the copyright and grant the journal the right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after its publication in ETASR with an acknowledgement of its initial publication in this journal.
