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Differential Power Processing System for the Capacitor Voltage Balancing of Cost-effective Photovoltaic Multi-level Inverters

  • Jeon, Young-Tae (Department of Electrical Engineering, Soongsil University) ;
  • Kim, Kyoung-Tak (Department of Electrical Engineering, Soongsil University) ;
  • Park, Joung-Hu (Department of Electrical Engineering, Soongsil University)
  • Received : 2016.11.30
  • Accepted : 2017.05.02
  • Published : 2017.07.20

Abstract

The Differential Power Processing (DPP) converter is a promising multi-module photovoltaic inverter architecture recently proposed for photovoltaic systems. In this paper, a DPP converter architecture, in which each PV-panel has its own DPP converter in shunt, performs distributed maximum power point tracking (DMPPT) control. It maintains a high energy conversion efficiency, even under partial shading conditions. The system architecture only deals with the power differences among the PV panels, which reduces the power capacity of the converters. Therefore, the DPP systems can easily overcome the conventional disadvantages of PCS such as centralized, string, and module integrated converter (MIC) topologies. Among the various types of the DPP systems, the feed-forward method has been selected for both its voltage balancing and power transfer to a modified H-bridge inverter that needs charge balancing of the input capacitors. The modified H-bridge multi-level inverter had some advantages such as a low part count and cost competitiveness when compared to conventional multi-level inverters. Therefore, it is frequently used in photovoltaic (PV) power conditioning system (PCS). However, its simplified switching network draws input current asymmetrically. Therefore, input capacitors in series suffer from a problem due to a charge imbalance. This paper validates the operating principle and feasibility of the proposed topology through the simulation and experimental results. They show that the input-capacitor voltages maintain the voltage balance with the PV MPPT control operating with a 140-W hardware prototype.

Keywords

References

  1. P. Fairley, "Big solar's big surge," IEEE Spectrum, Vol. 52, No. 1, pp. 41-44, Jan. 2015. https://doi.org/10.1109/MSPEC.2015.6995632
  2. P. S. Shenoy, K. A. Kim, B. B. Johnson, and P. T. Krein, "Differential power processing for increased energy production and reliability of photovoltaic systems," IEEE Trans. Power Electron., Vol. 28, No. 6, pp. 2968-2979, Jun. 2013. https://doi.org/10.1109/TPEL.2012.2211082
  3. M. S. Manoharan, A. Ahmed, J.-W. Seo, and J.-H. Park, "Power conditioning for a small-scale pv system with charge-balancing integrated micro-inverter," Journal of Power Electronics, Vol. 15, No. 5, pp. 1318-1328, Sep. 2015. https://doi.org/10.6113/JPE.2015.15.5.1318
  4. S.-J. Park, J.-H. Shin, J.-H. Park, and H.-J. Jeon, "Dynamic analysis and controller design for standalone operation of photovoltaic power conditioners with energy storage," Journal of Electrical Engineering and Technology, Vol. 9, No. 6, pp. 2004-2012, Nov. 2014. https://doi.org/10.5370/JEET.2014.9.6.2004
  5. M. S. Manoharan, A. Ahmed, and J.-H. Park, "Peak-valley current mode controlled h-bridge inverter with digital slope compensation for cycleby-cycle current regulation," Journal of Electrical Engineering and Technology, Vol. 10, No. 5, pp. 1989-2000, Sep. 2015. https://doi.org/10.5370/JEET.2015.10.5.1989
  6. S. M. MacAlpine, R. W. Erickson, and M. J. Brandemuehl, "Characterization of power optimizer potential to increase energy capture in photovoltaic systems operating under nonuniform conditions," IEEE Trans. Power Electron., Vol. 28, No. 6, pp. 2936-2945, Jun. 2013. https://doi.org/10.1109/TPEL.2012.2226476
  7. N. Femia, G. Lisi, G. Petrone, G. Spagnuolo, and M. Vitelli, "Distributed maximum power point tracking of photovoltaic arrays: Novel approach and system analysis," IEEE Trans. Ind. Electron., Vol. 55, No. 7, pp. 2610-2621, Jul. 2008. https://doi.org/10.1109/TIE.2008.924035
  8. C. Olalla, D. Clement, M. Rodriguez, and D. Maksimovic, "Architectures and control of submodule integrated dc-dc converters for photovoltaic applications," IEEE Trans. Power Electron., Vol. 28, No. 6, pp. 2980-2997, Jun. 2013. https://doi.org/10.1109/TPEL.2012.2219073
  9. S. Qin, S. T. Cady, A. D. Dominguez-Garcia, and R. C. N. Pilawa- Podgurski, "A distributed approach to maximum power point tracking for photovoltaic submodule differential power processing," IEEE Trans. Power Electron., Vol. 30, No. 4, pp. 2024-2040, Apr. 2015. https://doi.org/10.1109/TPEL.2014.2330335
  10. R. Bell and R. C. N. Pilawa-Podgurski, "Decoupled and distributed maximum power point tracking of series-connected photovoltaic submodules using differential power processing," IEEE J. Emerg. Sel. Topics Power Electron., Vol. 3, No. 4, pp. 881-891, Dec. 2015. https://doi.org/10.1109/JESTPE.2015.2475607
  11. T. V. Thang, N. M. Thao, J.-H. Jang, and J.-H. Park, "Analysis and design of grid-connected photovoltaic systems with multiple-integrated converters and a pseudo-dc-link inverter," IEEE Trans. Ind. Electron., Vol. 61, No. 7, pp. 3377-3386, Jul. 2014. https://doi.org/10.1109/TIE.2013.2281153
  12. J.-H. Park, J.-Y. Ahn, B.-H. Cho, and G.-J. Yu, "Dual-module-based maximum power point tracking control of photovoltaic systems," IEEE Trans. Ind. Electron., Vol. 53, No. 4, pp. 1036-1047, Jun. 2006. https://doi.org/10.1109/TIE.2006.878330
  13. A. Ahmed, P. Ganeshkumar, J.-H. Park, and H. Lee, "FPGA-based centralized controller for multiple PV generators tied to the DC bus," Journal of Power Electronics, Vol. 14, No. 4, pp. 733-741, Jul. 2014. https://doi.org/10.6113/JPE.2014.14.4.733
  14. Y.-T. Jeon, H.-J. Lee, K. A. Kim, and J.-H. Park, "Least power point tracking method for photovoltaic differential power processing systems," IEEE Trans. Power Electron., Vol. 32, No. 3, pp. 1941-1951, Mar. 2017. https://doi.org/10.1109/TPEL.2016.2556746
  15. M. F. N. Tajuddin, N. H. Ghazali, T. C. Siong, and N. Ghazali, "Modelling and simulation of modified unipolar PWM scheme on a single phase DC-AC converter using PSIM," in IEEE Student Conference on Research and Development (SCOReD), pp. 328-331, Nov. 2009.
  16. C. Olalla, C. Deline, D. Clement, Y. Levron, M. Rodriguez, and D. Maksimovic,"Performance of power-limited differential power processing architectures in mismatched pv systems," IEEE Trans. Power Electron., Vol. 30, No. 2, pp. 618-631, Feb. 2015. https://doi.org/10.1109/TPEL.2014.2312980
  17. Y. Levron, D. R. Clement, B. Choi, C. Olalla, and D. Maksimovic, "Control of submodule integrated converters in the isolated-port differential power-processing photovoltaic architecture," IEEE J. Emerg. Sel. Topics Power Electron., Vol. 2, No. 4, pp. 821-832, Dec. 2014. https://doi.org/10.1109/JESTPE.2014.2326972
  18. S. Ben-Yaakov, A. Blumenfeld, A. Cervera, and M. Evzelman, "Design and evaluation of a modular resonant switched capacitors equalizer for PV panels," in IEEE Energy Conversion Congress and Exposition (ECCE), pp. 4129-4136, Sep. 2012.
  19. C. Schaef, K. Kesarwani, and J. T. Stauth, "A coupled-inductor multilevel ladder converter for sub-module PV power management," in Twenty-Eighth Annaul IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 732-737, Mar. 2013.
  20. B.-M. Choi, J.-W. Seo, J.-H. Park, and J.-Y. Kim, "Design and implementation of shuffling micro-converter with boost converter," in KIPE, Autumm Conference, pp. 27-28, Nov. 2013.
  21. D. Thenathayalan, A. Ahmed, B.-M. Choi, J.-H. Park, and J.-H. Park, "Independent MPP tracking method of hybrid solar-wind power conditioning systems using integrated dual-input single-PWM-cell converter topology," Journal of Electrical Engineering and Technology, Vol. 12, No. 2, pp. 790-802, Mar. 2017. https://doi.org/10.5370/JEET.2017.12.2.790
  22. Y.-T. Jeon, J.-H. Park, and J.-H. Park, "Differential power processing converter with cell balancing operation of multiple photovoltaic module systems," IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), pp. 736-740, May 2016.
  23. H.-J. Lee, J.-H. Park, and J. Kim, "Comparative analysis of SOC estimation using EECM and NST in rechargeable $LiCoO_2/LiFePO_4/LiNiMnCoO_2$ cells," Journal of Electrical Engineering and Technology, Vol. 11, No. 6, pp. 1664-1673, Nov. 2016. https://doi.org/10.5370/JEET.2016.11.6.1664