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Control Strategy and Stability Analysis of Virtual Synchronous Generators Combined with Photovoltaic Dynamic Characteristics

  • Ding, Xiying (Shenyang University of Technology) ;
  • Lan, Tianxiang (Shenyang University of Technology) ;
  • Dong, Henan (Liaoning Electric Power Company Electric Power Research Institute, State Grid Corporation of China)
  • 투고 : 2019.03.11
  • 심사 : 2019.05.29
  • 발행 : 2019.09.20

초록

A problem with virtual synchronous generator (VSG) systems is that they are difficult to operate stably with photovoltaic (PV) power as the DC side. With this problem in mind, a PV-VSG control strategy considering the dynamic characteristics of the DC side is proposed after an in-depth analysis of the dynamic characteristics of photovoltaic power with a parallel energy-storage capacitor. The proposed PV-VSG automatically introduces DC side voltage control for the VSG when the PV enters into an unstable working interval, which avoids the phenomenon where an inverter fails to work due to a DC voltage sag. The stability of the original VSG and the proposed PV-VSG were compared by a root locus analysis. It is found that the stability of the PV-VSG is more sensitive to the inertia coefficient J than the VSG, and that a serious power oscillation may occur. According to this, a new rotor model is designed to make the inertial coefficient automatically change to adapt to the operating state. Experimental results show that the PV-VSG control strategy can achieve stable operation and maximum power output when the PV output power is insufficient.

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참고문헌

  1. M. Guan, W. Pan, J. Zhang, Q. Hao, J. Cheng, and X. Zheng, “Synchronous generator emulation control strategy for voltage source converter (VSC) stations,” IEEE Trans. Power Syst., Vol. 30, No. 6, pp. 3093-3101, Nov. 2015. https://doi.org/10.1109/TPWRS.2014.2384498
  2. Q. Zhong and G. Weiss, “Synchronverters: Inverters that mimic synchronous generators,” IEEE Trans. Ind. Electron., Vol. 58, No. 4, pp. 1259-1267, Apr. 2011. https://doi.org/10.1109/TIE.2010.2048839
  3. J. Alipoor, Y. Miura, and T. Ise, “Stability assessment and optimization methods for microgrid with multiple VSG units,” IEEE Trans Smart Grid, Vol. 9, No. 2, pp. 1462-1471, Mar. 2018. https://doi.org/10.1109/TSG.2016.2592508
  4. Q. Zhong, P. L. Nguyen, Z. Ma, and W. Sheng, “Selfsynchronized synchronverters: Inverters without a dedicated synchronization unit,” IEEE Trans. Power Electron., Vol. 29, No. 2, pp. 617-630, Feb. 2014. https://doi.org/10.1109/TPEL.2013.2258684
  5. J. Fang, Y. Tang, H. Li, and X. Li, “A battery/ ultracapacitor hybrid energy storage system for implementing the power management of virtual synchronous generators,” IEEE Trans. Power Electron., Vol. 33, No. 4, pp. 2820-2824, Apr. 2017. https://doi.org/10.1109/tpel.2017.2759256
  6. M. Torres, L. Lopes, L. Moran, and J. Espinoza, “Self-tuning virtual synchronous machine: A control strategy for energy storage systems to support dynamic frequency control,” IEEE Trans Energy Convers., Vol. 29, No. 4, pp. 833-840, Dec. 2014. https://doi.org/10.1109/TEC.2014.2362577
  7. D. Rekioua, and E. Matagne, Optimization of Photovoltaic Power Systems: Modelization, Simulation and Control, Springer London, Chap. 2, pp. 37-64, 2012.
  8. Q. Zhong and T. Hornik, Control of Power Inverters in Renewable Energy and Smart Grid Integration, Wiley-IEEE Press, Chap. 3, 2012.
  9. S. D. Arco, J. A. Suul, and O. B. Fosso, "A virtual synchronous machine implementation for distributed control of power converters in smartgrids," Electr. Power Syst. Res., Vol. 122, pp. 180-197, May. 2015. https://doi.org/10.1016/j.epsr.2015.01.001
  10. J. Liu, Y. Miura, and T. Ise, “Comparison of dynamic characteristics between virtual synchronous generator and droop control in inverter-based distributed generators,” IEEE Trans. Power Electron., Vol. 31, No. 5, pp. 3600-3611, May 2016. https://doi.org/10.1109/TPEL.2015.2465852
  11. H. Xin, Y. Liu, Z. Wang, D. Gan, and T. Yang, "A new frequency regulation strategy for photovoltaic systems without energy storage," IEEE Trans. Sustain. Energy, Vol. 4, No 4, pp. 985-993, Oct. 2013. https://doi.org/10.1109/TSTE.2013.2261567
  12. R. Zhang, H. Zhang, W, Feng, and K. Sun, "Small signal analysis of photovoltaic-energy storage integrated virtual synchronous generator," in Proc. IEEE Ind. Eect. Soc., pp. 1544-1549, 2017.
  13. M. Torres, C. Baier, J. M. Mauricio, and J. Silva, "Nonlinear control of a grid-connected multi-cell photovoltaic inverter that operates under variable temperature and irradiance" in Proc. IEEE Ind. Tech., pp. 17-19, 2015.
  14. J. Alipoor, Y. Miura, and T. Ise, “Power system stabilization using virtual synchronous generator with alternating moment of inertia,” IEEE J. Emerg. Sel. Topics Power Electron., Vol. 3, No. 2, pp. 451-458, Jun. 2015. https://doi.org/10.1109/JESTPE.2014.2362530
  15. A. Vassilakis, P. Kotsampopoulos, N. Hatziargyriou, and V. Karapanos, "A battery energy storage based virtual synchronous generator," in Proc. IEEE, IREP Symp. Bulk Power Syst. Dyn. and Control, pp. 25-30, 2013.
  16. J. Liu, Y. Miura, H. Bevrani, and T. Ise, “Enhanced virtual synchronous generator control for parallel inverters in microgrids,” IEEE Trans. Smart Grid, Vol. 8, No. 5, pp. 2268-2277, Sep. 2017. https://doi.org/10.1109/TSG.2016.2521405
  17. H. Bevrani, T. Ise, and Y. Miura, "Virtual synchronous generators: A survey and new perspectives," Int. J. Electr. Power Energy Syst., Vol. 54, pp. 244-254, Jan. 2014. https://doi.org/10.1016/j.ijepes.2013.07.009
  18. Y. Wei, H. Zhang, and K. Sun, "Pre-synchronization method of virtual synchronous generator using virtual power," Autom. Electr. Power Syst., Vol. 12, pp. 124-129, Dec. 2016.
  19. L. Huang, L. Zhang, and H. Xin, "Mechanism analysis of virtual power angle stability in droop-controlled inverters," Autom. Electr. Power Syst., Vol. 12, pp. 117-123, Dec. 2016.
  20. T. Shintai, Y. Miura, and T. Ise, “Oscillation damping of a distributed generator using a virtual synchronous generator,” IEEE Trans. Power Del., Vol. 29, No. 2, pp. 668-676, Apr. 2014. https://doi.org/10.1109/TPWRD.2013.2281359