Three-Phase CH7 Inverter With a New Space Vector Modulation to Reduce Leakage Current for Transformerless Photovoltaic Systems

Leakage current reduction is crucial for the transformerless photovoltaic inverters. The conventional three-phase current source H6 inverter suffers from the large leakage current, which restricts its application to transformerless PV systems. In order to overcome the limitations, a new three-phase current source H7 (CH7) inverter is proposed in this paper. Only one additional Insulated Gate Bipolar Transistor is needed, but the leakage current can be effectively suppressed with a new space vector modulation (SVM). Finally, the experimental tests are carried out on the proposed CH7 inverter, and the experimental results verify the effectiveness of the proposed topology and SVM method.

[1]  Yu Zhang,et al.  Simplified Model and Control Strategy of Three-Phase PWM Current Source Rectifiers for DC Voltage Power Supply Applications , 2015, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[2]  Xiaoqiang Guo,et al.  Hardware-Based Cascaded Topology and Modulation Strategy With Leakage Current Reduction for Transformerless PV Systems , 2016, IEEE Transactions on Industrial Electronics.

[3]  Li Zhang,et al.  H6 Transformerless Full-Bridge PV Grid-Tied Inverters , 2014, IEEE Transactions on Power Electronics.

[4]  Sakutaro Nonaka.  A suitable single-phase PWM current source inverter for utility connected residential PV system , 1994 .

[5]  Frede Blaabjerg,et al.  A Modified LLCL Filter With the Reduced Conducted EMI Noise , 2013, IEEE Transactions on Power Electronics.

[6]  Xiaoqiang Guo,et al.  A new three-level six-switch topology for transformerless photovoltaic systems , 2012, Proceedings of The 7th International Power Electronics and Motion Control Conference.

[7]  M. Kazerani,et al.  Dynamic Modeling and Performance Analysis of a Grid-Connected Current-Source Inverter-Based Photovoltaic System , 2011, IEEE Transactions on Sustainable Energy.

[8]  Zaijun Wu,et al.  A Family of Zero-Current-Transition Transformerless Photovoltaic Grid-Connected Inverter , 2015, IEEE Transactions on Power Electronics.

[9]  K. Sun,et al.  Improved Modeling of Medium Voltage SiC MOSFET Within Wide Temperature Range , 2014, IEEE Transactions on Power Electronics.

[10]  Xiaoqiang GUO,et al.  New inverter topology for ground current suppression in transformerless photovoltaic system application , 2014 .

[11]  Bin Wu,et al.  Common-Mode Voltage Mitigation for Back-to-Back Current-Source Converter With Optimal Space-Vector Modulation , 2016, IEEE Transactions on Power Electronics.

[12]  Yang Zheng,et al.  Design and Control of a Photovoltaic Energy and SMES Hybrid System With Current-Source Grid Inverter , 2013, IEEE Transactions on Applied Superconductivity.

[13]  Josep M. Guerrero,et al.  Leakage Current Elimination of Four-Leg Inverter for Transformerless Three-Phase PV Systems , 2016, IEEE Transactions on Power Electronics.

[14]  Xiaoqiang Guo,et al.  Flexible Power Regulation and Current-Limited Control of the Grid-Connected Inverter Under Unbalanced Grid Voltage Faults , 2017, IEEE Transactions on Industrial Electronics.

[15]  Yang Chen,et al.  Three-Phase Boost-Type Grid-Connected Inverter , 2008, IEEE Transactions on Power Electronics.

[16]  P. G. Vidal,et al.  Characterization of the insulation and leakage currents of PV generators: Relevance for human safety , 2010 .

[17]  Bin Wu,et al.  Common-Mode Voltage Reduction Methods for Current-Source Converters in Medium-Voltage Drives , 2013, IEEE Transactions on Power Electronics.

[18]  Frede Blaabjerg,et al.  Reliability of Capacitors for DC-Link Applications in Power Electronic Converters—An Overview , 2014, IEEE Transactions on Industry Applications.

[19]  Changliang Xia,et al.  Topology Review and Derivation Methodology of Single-Phase Transformerless Photovoltaic Inverters for Leakage Current Suppression , 2015, IEEE Transactions on Industrial Electronics.

[20]  Xiaoqiang Guo,et al.  A Novel CH5 Inverter for Single-Phase Transformerless Photovoltaic System Applications , 2017, IEEE Transactions on Circuits and Systems II: Express Briefs.