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http://dx.doi.org/10.6113/JPE.2015.15.4.920

A Family of Non-Isolated Photovoltaic Grid Connected Inverters without Leakage Current Issues  

Ji, Baojian (College of Automation and Electrical Engineering, Nanjing Tech University)
Wang, Jianhua (School of Electrical Engineering, Southeast University)
Hong, Feng (College of Electronic and Information Eng., Nanjing University of Aeronautics and Astronautics)
Huang, Shengming (College of Automation and Electrical Engineering, Nanjing Tech University)
Publication Information
Journal of Power Electronics / v.15, no.4, 2015 , pp. 920-928 More about this Journal
Abstract
Transformerless solar inverters have a higher efficiency than those with an isolation link. However, they suffer from a leakage current issue. This paper proposes a family of single phase six-switch transformerless inverter topologies with an ac bypass circuit to solve the leakage current problem. These circuits embed two unidirectional freewheeling current units into the midpoint of a full bridge inverter, to obtain a freewheeling current path, which separates the solar panel from the grid in the freewheeling state. The freewheeling current path contains significantly fewer devices and poor performance body diodes are not involved, leading to a higher efficiency. Meanwhile, it is not necessary to add a voltage balancing control method when compared with the half bridge inverter. Simulation and experiments are provided to validate the proposed topologies.
Keywords
Common-mode voltage; Leakage current; Non-isolated inverter; Photovoltaic;
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1 T. Kerekes, R. Teodorescu, P. Rodriguez, G. Vazquez, and E. Aldabas, “A new high-efficiency single-phase transformerless PV inverter topology,” IEEE Trans. Ind. Electron., Vol. 58, No. 1, pp. 184-191, Jan. 2011.   DOI
2 W. Yu, J.-S. La, H. Qian and C. Hutchens, “High-efficiency MOSFET inverter with H6-type configuration for photovoltaic nonisolated AC-module applications,” IEEE Trans. Power Electron., Vol. 26, No. 4, pp. 1253-1260, Apr. 2011.   DOI
3 R. Gonzalez, J. Lopez, P. Sanchis, E. Gubia, A. Ursua, and L. Marroyo, “High efficiency transformerless single-phase photovoltaic inverter,” 12th International Power Electronics and Motion Control Conference, pp. 1895-1900, 2006.
4 W. Cui, B. Yang, Y. Zhao, W. Li, and X. He, “A novel single-phase transformerless photovoltaic inverter connected to grid,” IEEE PEMD Proceeding, pp. 1126-1130, 2010.
5 B. Ji, J. Wang, and J. Zhao, “High-efficiency single-phase transformerless PV H6 inverter with hybrid modulation method,” IEEE Trans. Ind. Electron., Vol. 60, No. 5, pp. 2104-2115, May 2013.   DOI
6 J. Wang, B. Ji, J. Zhao, and J. Yu, "From H4, H5 to H6 - Standardization of full-bridge single phase photovoltaic inverter topologies without ground leakage current issue," in Proc. IEEE ECCE, pp. 2419-2425, 2012.
7 M. Ciobotaru, R. Teodorescu, and F. Blaabjerg, "A new single-phase PLL structure based on second order generalized integrator," in Proc. IEEE PESC, pp. 1-6, 2006.
8 X. Guo, H. Wang, Z. Lu, and B. Wang, “New inverter topology for ground current suppression in transformerless photovoltaic system application,” Journal of Modern Power Systems and Clean Energy, Vol. 2, No. 2, pp. 191-194, May 2014.   DOI
9 M. C. Cavalcanti, A. M. Farias, K. C. de Oliveira, F. A. S. Neves, and J. L. Afonso, “Eliminating leakage currents in neutral point clamped inverters for photovoltaic systems,” IEEE Trans. Ind. Electron., Vol.59, No.1, pp. 435-443, Jan. 2012.   DOI
10 S. Aeaujo, P. Zacharias, and R. Mallwitz, “Highly efficient single-phase transformerless inverters for grid-connected photovoltaic systems,” IEEE Trans. Ind. Electron., Vol.57, No.9, pp. 3118-3128, Sep. 2010.   DOI
11 T. Kerekes, R. Teodorescu, P. Rodriguez, G. Vazquez, and E. Aldabas, “A new high-efficiency single-phase transformerless PV inverter topology,” IEEE Trans. Ind. Electron., Vol. 58, No. 1, pp. 184-191, Jan. 2011.   DOI
12 M. C. Cavalcanti, K. C. de Oliveira, A. M. de Farias, F. A. S. Neves, G. M. S. Azevedo, and F. C. Camboim, “Modulation techniques to eliminate leakage currents in transformerless three-phase photovoltaic systems,” IEEE Trans. Ind. Electron., Vol. 57, No. 4, pp. 1360-1368, Apr. 2010.   DOI
13 O. Lopez, R. Teosorescu, F. Freijedo, and J. DovalGandoy, "Leakage current evaluation of a single phase transformerless PV inverter connected to the grid," in Proc. IEEE APEC., pp. 907-912, 2007.
14 F. Bradaschia, M. C. Cavalcanti, P. E. P. Ferraz, F. A. S. Neves, E. C. dos Santos, and J. H. G. M. da Silva, “Modulation for three-phase transformerless Z-source inverter to reduce leakage currents in photovoltaic systems,” IEEE Trans. Ind. Electron., Vol. 58, No. 12, pp. 5385-5395, Dec. 2011.   DOI
15 R. Gonzáalez, J. Lóopez, 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.   DOI
16 R. Gonzalez, E. Gubia, J. Lopez, and L. Marroyo, “Transformerless single-phase multilevel-based photovoltaic inverter,” IEEE Trans. Ind. Electron., Vol. 55, No. 7, pp. 2694-2702, Jul. 2008.   DOI
17 DIN V VDE V 0126-1-1, Automatic Disconnection Device Between a Generator and the Public Low-Voltage Grid, Germany: VDE Press, 2006.
18 German Patent HERIC-Topology: DE 102 21 592 A1, issued 04.12.2003.
19 German Patent H5-Topology: DE 10 2004 030 912 B3, issued 19.01.2006.