Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
권호 표지
DOI QR코드

DOI QR Code

DG-side earth fault tolerance enhancement based on topology improvement and common and differential mode control strategy

  • Zhang, Yong (College of Electrical Engineering, Zhejiang University) ;
  • Yu, Miao (College of Electrical Engineering, Zhejiang University) ;
  • Xia, Yanghong (College of Electrical Engineering, Zhejiang University) ;
  • Wei, Wei (College of Electrical Engineering, Zhejiang University)
  • Received : 2020.01.05
  • Accepted : 2020.05.04
  • Published : 2020.07.20
⟨ Previous Next ⟩

Abstract

Parallel distributed generation (DG) can extract power from a renewable energy source and supply it to the grid, but the exposure of DG components, such as photovoltaic panels, to the natural environment results in DG-side earth faults and common earth circulating current (CECC) problems. This study proposes an improved topology and a common and differential (C&D) mode control strategy to enhance the earth fault tolerance in parallel DG systems. First, the effects of line resistances and input voltages on CECC are analyzed through a mathematical model, and the disadvantages of the conventional buck converter are identified. Second, an additional switch in a negative pole is designed for the application of the C&D control strategy. Specifically, common-mode algorithm control is used to inhibit CECC, and differential-mode control is applied to ensure current sharing accuracy. Third, an inertial element is added to the reference voltage to restore the bus voltage produced by the differential-mode control strategy. Lastly, an experiment is conducted to verify that the proposed control outperforms conventional control in various conditions.

Keywords

Acknowledgement

This work was funded by the National Natural Science Foundation of China (No. U1909201), the National Key Research and Development Program of China (2018YFB0904700), the State Grid Science and Technology Program (SGDK0000PDJS1806935), and a project funded by China Postdoctoral Science Foundation (2019M660139).

References

  1. Huang, S., Luo, J.: Multi-function distributed generation with active power filter and reactive power compensator. J. Power Electron. 18(6), 1855-1865 (2018) https://doi.org/10.6113/JPE.2018.18.6.1855
  2. Lee, Y.S., Yang, W.M., Han, B.M.: Islanding detection method for inverter-based distributed generation through injection of second order harmonic current. J. Power Electron. 18(5), 1513-1522 (2018) https://doi.org/10.6113/JPE.2018.18.5.1513
  3. Guo, Q., Cai, H., Wang, Y.: Distributed secondary voltage control of islanded microgrids with event-triggered scheme. J. Power Electron. 17(6), 1650-1657 (2017) https://doi.org/10.6113/JPE.2017.17.6.1650
  4. Ahmadi, T., Hamzeh, M., Rokrok, E.: Hierarchical control scheme for three-port multidirectional dc-dc converter in bipolar DC microgrids. J. Power Electron. 18(5), 1595-1607 (2018) https://doi.org/10.6113/JPE.2018.18.5.1595
  5. Ahmadi, T., Rokrok, E., Hamzeh, M.: Mitigation of voltage unbalances in bipolar dc microgrids using three-port multidirectional dc-dc converters. J. Power Electron. 18(4), 1223-1234 (2018) https://doi.org/10.6113/JPE.2018.18.4.1223
  6. Dragicevic, T., Lu, X., Vasquez, J.C., et al.: DC microgrids-part I: a review of control strategies and stabilization techniques. IEEE Trans. Power Electron. 31(7), 4876-4891 (2016) https://doi.org/10.1109/TPEL.2015.2478859
  7. Zhang, Y, Yu, M, Xia, Y, et al.: A comprehensive suppression strategy for common ground circulating current caused by grounding fault in PV modules. IEEE J. Emerg. Select. Top. Power Electron. (2019). https://doi.org/10.1109/JESTPE.2019.2907297
  8. Mackay L, Vandeventer E, Ramirez-Elizondo L (2018) Circulating net currents in meshed DC distribution grids: a challenge for residual ground fault protection. IEEE Trans. Power Delivery. 33(2):1018-1019 https://doi.org/10.1109/TPWRD.2018.2799478
  9. Elserougi, A.A., Massoud, A.M., Abdel-Khalik, A.S., et al.: Bidirectional buck-boost inverter-based HVDC transmission system with ac-side contribution blocking capability during dc-side faults. IEEE Trans. Power Delivery 29(3), 1249-1261 (2014) https://doi.org/10.1109/TPWRD.2014.2308274
  10. F. Zhang, G. Joos, W. Li: A transformer-less modular multilevel DC-DC converter with DC fault blocking capability. In: IEEE Southern Power Electronics Conference (SPEC), Puerto Varas, pp. 1-6. (2017)
  11. Shoyama, M., Li, G., Ninomiya, T.: Balanced switching converter to reduce common-mode conducted noise. IEEE Trans. Ind. Electron. 50(6), 1095-1099 (2003) https://doi.org/10.1109/TIE.2003.819677
  12. Zhang, S., Lin, S., He, Z., et al.: Ground fault location in radial distribution networks involving distributed voltage measurement. IET Gener. Transm. Distrib. 12(4), 987-996 (2018) https://doi.org/10.1049/iet-gtd.2017.1166
  13. Jayakumar, N.K.T., et al.: Post processing for improved accuracy and resolution of spread spectrum time-domain reflectometry. IEEE Sens. Lett. 3(6), 1-4 (2019) https://doi.org/10.1109/LSENS.2019.2916636
  14. C. Furse, N. Jayakumar, E. Benoit, et al.: Spread spectrum time domain reflectometry for complex impedances: application to PV arrays. In: IEEE AUTOTESTCON, National Harbor, MD, pp. 1-4 (2018)
  15. Shi, J., Liu, T., Cheng, J., et al.: Automatic current sharing of an input-parallel output-parallel (IPOP)-connected DC-DC converter system with chain-connected rectifiers. IEEE Trans. Power Electron. 30(6), 2997-3016 (2015) https://doi.org/10.1109/TPEL.2014.2334896
  16. Liu, C., Xu, X., He, D., et al.: Magnetic-coupling current-balancing cells based input-parallel output-parallel LLC resonant converter modules for high-frequency isolation of DC distribution systems. IEEE Trans. Power Electron. 31(10), 6968-6979 (2016) https://doi.org/10.1109/TPEL.2015.2507172
  17. Xia, Y., Wei, W., Peng, Y., et al.: Decentralized coordination control for parallel bidirectional power converters in a grid-connected DC microgrid. IEEE Trans. Smart Grid 9(6), 6850-6861 (2018) https://doi.org/10.1109/tsg.2017.2725987
  18. Lyu, J., Zhang, J., Cai, X., et al.: Circulating current control strategy for parallel full-scale wind power converters. IET Power Electron. 9(4), 639-647 (2016) https://doi.org/10.1049/iet-pel.2014.0926
  19. Siri, K., Banda, J.: Analysis and evaluation of current-sharing control for parallel-connected DC-DC converters taking into account cable resistance. IEEE Aerosp. Appl. Conf. Proc. Aspen CO 2, 29-48 (1995)
  20. Tsai-Fu, Wu, Chen, Y.-K., Huang, Y.-H.: 3C strategy for inverters in parallel operation achieving an equal current distribution. IEEE Trans. Industr. Electron. 47(2), 273-281 (2000) https://doi.org/10.1109/41.836342
  21. Guerrero, J.M., Matas, J., Garcia de Vicuna, L., et al.: Decentralized control for parallel operation of distributed generation inverters using resistive output impedance. IEEE Trans. Industr. Electron. 54(2), 994-1004 (2007) https://doi.org/10.1109/TIE.2007.892621
  22. Chen, X., Hou, Y., Hui, S.Y.R.: Distributed control of multiple electric springs for voltage control in microgrid. IEEE Trans. Smart Grid 8(3), 1350-1359 (2017) https://doi.org/10.1109/TSG.2016.2632152
  23. Lu, X., Guerrero, J.M., Sun, K., et al.: An improved droop control method for DC microgrids based on low bandwidth communication with DC bus voltage restoration and enhanced current sharing accuracy. IEEE Trans. Power Electron. 29(4), 1800-1812 (2014) https://doi.org/10.1109/TPEL.2013.2266419
  24. Xia, Y., Peng, Y., Wei, W.: Triple droop control method for ac microgrids. IET Power Electron. 10(13), 1705-1713 (2017) https://doi.org/10.1049/iet-pel.2017.0005

Cited by

  1. An Online Novel Two-Layered Photovoltaic Fault Monitoring Technique Based Upon the Thermal Signatures vol.12, pp.22, 2020, https://doi.org/10.3390/su12229607