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Comparative Analysis of Grid Connected Transformerless Photovoltaic Inverters for Leakage Current Minimization


Affiliations
1 Department of Electrical and Electronics Engineering, SSN college of Engineering, Kalavakkam, Tamil Nadu – 63110, India
 

Objectives: To make a comparative analysis of four transformerless topologies namely H5, H6, oH5 and H-Bridge Zero Voltage State Rectifier (HBZVR) in terms of leakage current and THD. Methods/Statistical Analysis: H5, H6, oH5 and HBZVR topologies have been simulated. Then these topologies are compared in terms of leakage current and THD. Based on the comparative analysis, the topology with less leakage current and THD has been chosen for photovoltaic interface. The interfacing circuit is simulated and realized as prototype to validate the results practically. Findings: It is found from the review that HBZVR topology has less leakage current and THD. This topology employs both galvanic isolation and Common Mode Voltage (CMV) clamping. It is found that the common mode voltage in HBZVR is almost eliminated. The conclusion derived from this paper may be helpful in selecting proper topology for PV interface. Application/ Improvements: Generally, in grid connected PV inverters, transformers provide galvanic isolation between the two electrical circuits, thus preventing the flow of leakage current between the stray capacitance of PV and ground. But, ransformers reduce the overall efficiency of the system, which lead to the development of transformerless PV system. Galvanic connection exists between the PV and grid in transformerless inverter, which leads to the presence of leakage current. So, to reduce leakage current, many topologies are introduced which employs either dc-decoupling or ac-decoupling to provide galvanic isolation. The HBZVR topology provides proper isolation for PV interface where the capacitance of the panel with respect to ground is large.
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  • Suan FTK, Rahim NA, Ping HW. Modeling, analysis and control of various types of transformerless grid connected PV inverters. Proceedings of IEEE Clean Energy Technology, Malaysia; 2011 Jun. p. 51–6.

  • Li Q, Wolfs P. A review of the single phase photovoltaic module integrated converter topologies with three different dc link configurations. IEEE Transactions on Power Electronics. 2008 May; 23(3):1320–33. Crossref.

  • Gonzalez R, Lopez J, Sanchis P, Marroyo L. Transformerless inverter for single-phase photovoltaic systems. IEEE Transactions on Power Electronics. 2007 Mar, 22(2):693–7. Crossref.

  • Kerekes T, Teodorescu R, Liserre M, Klumpner C, Sumner M. Evaluation of three-phase transformerless photovoltaic inverter topologies. IEEE Transactions on Power Electronics. 2009 Aug; 24(9):2202–11. Crossref.

  • Rahim NA, Chaniago K, Selvaraj J. Single-phase sevenlevel grid connected inverter for photovoltaic system. IEEE Transactions on Industrial Electronics. 2011 Jun; 58(6):2435–43. Crossref.

  • Calais M, Myrzik M, Spooner T, Agelidis VG. Inverters for single phase grid connected photovoltaic system – An overview. IEEE Power Electronics Specialist Conference, Birmingham, United Kingdom; 2011 Aug; 4:1995–2000.

  • Patrao I, Figureueres E, González-Espin F, Garcera G. Transformerless topologies for grid connected single-phase photovoltaic inverters. Renewable and Sustainable Energy Reviews. 2011 Sep; 15(7):3423–31. Crossref.

  • Patel H, Agarwal VA. Single-stage single-phase transformerless doubly grounded grid-connected PV interface. IEEE Transactions on Energy Conversion. 2009 Mar; 24(1):93–101. Crossref.

  • Villalva MG, Gazoli JR, Filho ER. Comprehensive approach to modeling and simulation of photovoltaic arrays. IEEE Transactions on Power Electronics. 2009 May; 24(5):1198–208. Crossref.

  • Walker G. Evaluating MPPT converter topologies using a MATLAB PV model. Australian Journal of Electrical and Electronics Engineering. 2014 Oct; 21(1):49–55.

  • Zhang L, Sun K, Feng L, Wu H, Xing Y. A family of neutral point clamped full-bridge topologies for transformerless photovoltaic grid-tied inverters. IEEE Transactions on Power Electronics. 2013 Feb; 28(2):730–9. Crossref.

  • Araujo SV, Zacharias P, Mallwithz R. Highly efficient single phase transformerless inverters for grid-connected photovoltaic systems. IEEE Transactions on Industrial Electronics. 2010 Sep; 57(9):3118–28. Crossref.

  • Yang B, Li W, Gu Y, Cui W, He X. Improved transformerless inverter with common-mode leakage current elimination for a photovoltaic grid-connected power system. IEEE Transactions on Power Electronics. 2012 Feb; 27(2):752–62. Crossref.

  • Gubia E, Sanchis P, Ursua A, Lopez J, Marroyo L. Ground currents in single-phase transformerless photovoltaic systems. Progress in Photovoltaic Applications. 2007 Nov; 15(7):629–50. Crossref.

  • Xiao HF, Lan K, Zhang L. A quasi-unipolar SPWM fullbridge transformerless PV grid-connected inverter with constant common-mode voltage. IEEE Transactions on Power Electronics. 2015 Jun; 30(6):3122–32. Crossref.

  • Sekar RAR, Prasad DA. Improved transformerless inverter for PV grid connected power system by using ISPWM technique. International Journal of Engineering Trends and Technology. 2013 Apr; 4(5):1512–17.

  • Islam M, Hasan M, Akter P, Rahman MDM. A new transformerless inverter for grid connected photovoltaic system with low leakage current. International Conference on Electrical Information and Communication Technology (EICT), Bangladesh; 2013 Feb. p. 1–6. PMCid:PMC3794383

  • Yu W, Lai JS, Quian H, Hutchens C. High-efficiency MOSFET inverter with H6-type conFigureuration for photovoltaic non-isolated AC-module applications. IEEE Transactions on Power Electronics. 2011 Apr; 26(4):1253–60. Crossref.

  • Cavalcanti MC, De Oliveira KC, De Farias AM, Neves FAS, Azevedo GMS, Camboim FC. Modulation techniques to eliminate leakage currents in transformerless three-phase photovoltaic systems. IEEE Transactions on Industrial Electronics. 2010 Apr; 57(4):1360–8. Crossref.

  • Jasmine B, Anjumol CS. Leakage current elimination in single phase transformer less grid connected power systems. International Journal of Innovative Research in Electrical, Electronics, Instrumentation and Control Engineering. 2014 Mar; 2(3):1266–71.

  • Vazquez G, Kerekes T, Rolan A, Aguilar D, Luna A, Azevedo G. Losses and CMV evaluation in transformerless grid-connected PV topologies. Proceedings of the IEEE International Symposium on Industrial Electronics (ISlE 2009), Seoul; 2009 Jul. p. 544–8. Crossref.

  • Kerekes T, Teodorescu R, Rodríguez P, Vázquez G, Aldabas E. A new high-efficiency single-phase transformerless PV inverter topology. IEEE Transactions on Industrial Electronics. 2011 Jan; 58(1):184–91. Crossref.

  • Cha W-J, Kim K-T, Cho Y-W, Lee S-H, Kwon B-H. Evaluation and analysis of transformerless photovoltaic inverter topology for efficiency improvement and reduction of leakage current. IET Power Electronics. 2015 Feb; 8(2):255–67. Crossref.

  • Xiao H, Xie S, Chen Y, Huang R. An optimized transformerless photovoltaic grid-connected inverter. IEEE Transactions on Industrial Electronics. 2011 May; 58(5):1887–95. Crossref.


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  • Comparative Analysis of Grid Connected Transformerless Photovoltaic Inverters for Leakage Current Minimization

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Authors

A. Arrul Dhana Mathi
Department of Electrical and Electronics Engineering, SSN college of Engineering, Kalavakkam, Tamil Nadu – 63110, India
R. Ramaprabha
Department of Electrical and Electronics Engineering, SSN college of Engineering, Kalavakkam, Tamil Nadu – 63110, India

Abstract


Objectives: To make a comparative analysis of four transformerless topologies namely H5, H6, oH5 and H-Bridge Zero Voltage State Rectifier (HBZVR) in terms of leakage current and THD. Methods/Statistical Analysis: H5, H6, oH5 and HBZVR topologies have been simulated. Then these topologies are compared in terms of leakage current and THD. Based on the comparative analysis, the topology with less leakage current and THD has been chosen for photovoltaic interface. The interfacing circuit is simulated and realized as prototype to validate the results practically. Findings: It is found from the review that HBZVR topology has less leakage current and THD. This topology employs both galvanic isolation and Common Mode Voltage (CMV) clamping. It is found that the common mode voltage in HBZVR is almost eliminated. The conclusion derived from this paper may be helpful in selecting proper topology for PV interface. Application/ Improvements: Generally, in grid connected PV inverters, transformers provide galvanic isolation between the two electrical circuits, thus preventing the flow of leakage current between the stray capacitance of PV and ground. But, ransformers reduce the overall efficiency of the system, which lead to the development of transformerless PV system. Galvanic connection exists between the PV and grid in transformerless inverter, which leads to the presence of leakage current. So, to reduce leakage current, many topologies are introduced which employs either dc-decoupling or ac-decoupling to provide galvanic isolation. The HBZVR topology provides proper isolation for PV interface where the capacitance of the panel with respect to ground is large.

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DOI: https://doi.org/10.17485/ijst%2F2018%2Fv11i23%2F109686