Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Control stability of inverters with series-compensated transmission lines: analysis and improvement

  • Zhang, Qianjin (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Qian, Jinhui (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Zhai, Zhaorong (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Liu, Xiaodong (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Liu, Sucheng (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Fang, Wei (School of Electrical and Information Engineering, Anhui University of Technology) ;
  • Liu, Hongbo (Qingdao Power Supply Company, Shandong Electric Power Company of State Grid) ;
  • Abusara, Mohammad (Renewable Energy Multidisciplinary Group, University of Exeter)
  • Received : 2022.01.04
  • Accepted : 2022.06.16
  • Published : 2022.10.20
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Abstract

With the rapid development of renewable energy, large amounts of power need to be transmitted to load centers, and series-capacitor compensation (SCC) plays an important role in renewable power transmission. However, it has been pointed out that SCC interacts with inverters and threatens system stability. This paper investigates the influence of SCC on inverter control, and proposes strategies for enhancing system stability based on the instability mechanism. First, the impacts of SCC on inverter current control and synchronization control are analyzed. A current control model is established by a system transfer function, and a synchronization control model focusing on transient stability is established based on the traditional synchronous reference frame phase-locked loop (SRF-PLL). Bode and nonlinear analysis methods are utilized in the stability analysis of both current control and synchronization control. It is found that SCC has little effect on inverter current control. However, it seriously affects synchronization control. SCC reduces the stability range of synchronization control, and causes system instability when there is a large frequency disturbance. In order to improve system stability, two approaches have been proposed. These approaches are optimizing a PI controller, and designing a band-pass filter (BPF) inside the PLL. Finally, simulations and experiments are presented to verify the correctness of theories.

Keywords

Acknowledgement

This work was supported by the Youth Foundation of Anhui University of Technology under grant QZ202106 and the Natural Science Foundation of Colleges and Universities of Anhui Province under grant KJ2020A0246.

References

  1. Golestan, S., Guerrero, J.M., Vasquez, J.C.: Modeling and stability assessment of single-phase grid synchronization techniques: Linear time-periodic versus linear time-invariant frameworks. IEEE Trans. Power Electron. 34(01), 20-27 (2019) https://doi.org/10.1109/TPEL.2018.2835144
  2. Sun, J.: Impedance-based stability criterion for grid-connected inverters. IEEE Trans. Power Electron. 26(11), 3075-3078 (2011) https://doi.org/10.1109/TPEL.2011.2136439
  3. Liu, K., Cao, W., Wang, S.: Admittance modeling, analysis, and reshaping of harmonic control loop for multi-paralleled SAPFs system. IEEE Trans. Indus. Inf. 17(1), 280-289 (2021) https://doi.org/10.1109/TII.2020.2968374
  4. Peng, Q., Jiang, Q., Yang, Y.: On the stability of power electronics-dominated systems: challenges and potential solutions. IEEE Trans. Ind. Appl. 55(6), 7657-7670 (2019) https://doi.org/10.1109/TIA.2019.2936788
  5. Wang, J.G., Yan, J.D., Jiang, L.: Delay-dependent stability of single-loop controlled grid-connected inverters with LCL filters. IEEE Trans. Power Electron. 31(01), 743-757 (2016) https://doi.org/10.1109/TPEL.2015.2401612
  6. Jin, Y., Fang, T., Yao, K.: An improved time-delay compensation scheme for enhancing control performance of digitally controlled grid-connected inverter. In: 2019 IEEE Energy Conversion Congress and Exposition (ECCE), Baltimore, pp. 2772-2776 (2019)
  7. Li, Y., Gu, Y., Zhu, Y.: Impedance circuit model of grid-forming inverter: visualizing control algorithms as circuit elements. IEEE Trans. Power Electron. 36(3), 3377-3395 (2021) https://doi.org/10.1109/TPEL.2020.3015158
  8. Du, W., Tuffner, F., Schneider, K.P.: Modeling of grid-forming and grid-following inverters for dynamic simulation of largescale distribution systems. IEEE Trans. Power Delivery 36(4), 2035-2045 (2021)
  9. Zhang, Q., Zhou, L., Mao, M.: Power quality and stability analysis of large-scale grid-connected photovoltaic system considering non-linear effects. IET Power Electron. 11(11), 1739-1747 (2018) https://doi.org/10.1049/iet-pel.2018.0063
  10. Ren, Y., Wang, X., Chen, L.: A strictly sufficient stability criterion for grid-connected converters based on impedance models and Gershgorin's theorem. IEEE Trans. Power Deliv. 35(3), 1606-1609 (2020)
  11. Zhou, L., Wu, W., Chen, Y.: Virtual positive-damping reshaped impedance stability control method for the offshore MVDC system. IEEE Trans. Power Electron. 34(5), 4951-4966 (2019) https://doi.org/10.1109/TPEL.2018.2865446
  12. Kim, H., Jung, H., Sul, S.: Discrete-time voltage controller for voltage source converters with LC filter based on state-space models. IEEE Trans. Ind. Appl. 55(1), 529-540 (2019) https://doi.org/10.1109/TIA.2018.2868552
  13. Vennelaganti, S.G., Chaudhuri, N.R.: Stability criterion for inertial and primary frequency droop control in MTDC grids with implications on ratio-based frequency support. IEEE Trans. Power Syst. 35(5), 3541-3551 (2020) https://doi.org/10.1109/TPWRS.2020.2976817
  14. Al Hasnain, F., Sahami, A., Kamalasadan, S.: An online wide-area direct coordinated control architecture for power grid transient stability enhancement based on subspace identification. IEEE Trans. Ind. Appl. 57(3), 2896-2907 (2021) https://doi.org/10.1109/TIA.2021.3055446
  15. Zhang, C., Molinas, M., Rygg, A.: Impedance-based analysis of interconnected power electronics systems: impedance network modeling and comparative studies of stability criteria. IEEE J. Emerg. Sel. Top. Power Electron. 8(3), 2520-2533 (2020) https://doi.org/10.1109/JESTPE.2019.2914560
  16. Buraimoh, E., Davidson, I. E.: Simplified LCL filter state space modeling and small signal stability analysis of inverter based microgrid. In: 2021 IEEE PES/IAS PowerAfrica, Nairobi, pp. 1-5 (2021)
  17. Hu, J., Hu, Q., Wang, B.: Small signal instability of PLL-synchronized Type-4 wind turbines connected to high-impedance AC grid during LVRT. IEEE Trans. Energy Convers. 31(4), 1676-1687 (2016) https://doi.org/10.1109/TEC.2016.2577606
  18. Zhang, X., Xia, D., Fu, Z.: An improved feedforward control method considering PLL dynamics to improve weak grid stability of grid-connected inverters. IEEE Trans. Ind. Appl. 54(5), 5143-5151 (2018) https://doi.org/10.1109/TIA.2018.2811718
  19. Huang, L., Xin, H., Li, Z.: Grid-synchronization stability analysis and loop shaping for PLL-based power converters with different reactive power control. IEEE Trans. Smart Grid. 11(01), 501-516 (2020) https://doi.org/10.1109/TSG.2019.2924295
  20. He, X., Geng, H., Ma, S.: Transient stability analysis of grid-tied converters considering PLL's nonlinearity. CPSS Trans. Power Electron. Appl. 4(1), 40-49 (2019) https://doi.org/10.24295/CPSSTPEA.2019.00005
  21. Zhang, Q., Mao, M., Ke, G.: Stability problems of PV inverter in weak grid: a review. IET Power Electron. 13(11), 2165-2174 (2020) https://doi.org/10.1049/iet-pel.2019.1049
  22. Ghosh, S., Isbeih, Y.J., Bhattarai, R.: A dynamic coordination control architecture for reactive power capability enhancement of the DFIG-based wind power generation. IEEE Trans. Power Syst. 35(4), 3051-3064 (2020) https://doi.org/10.1109/TPWRS.2020.2968483
  23. Li, P., Xiong, L., Wang, Z.: Fractional-order sliding mode control for damping of subsynchronous control interaction in DFIG-based wind farms. Wind Energy 5(3), 749-762 (2020)
  24. Xu, Y., Zhao, S.: Mitigation of subsynchronous resonance in series-compensated DFIG wind farm using active disturbance rejection control. IEEE Access. 7, 68812-68822 (2019) https://doi.org/10.1109/ACCESS.2019.2919561
  25. Shair, J., Xie, X., Wang, L.: Overview of emerging subsynchronous oscillations in practical wind power systems. Renew. Sustain. Energy Rev. 99, 159-168 (2019) https://doi.org/10.1016/j.rser.2018.09.047
  26. Cao, N., Song, Z., Chong, K.: Research on SSCI caused of doubly fed wind power generation via fixed series compensated transmission. In: 2017 Chinese Automation Congress (CAC), Jinan, pp. 3711-3717 (2017)
  27. Ma, S., Geng, H., Liu, L.: Grid-synchronization stability improvement of large scale wind farm during severe grid fault. IEEE Trans. Power Syst. 33(1), 216-226 (2018) https://doi.org/10.1109/TPWRS.2017.2700050
  28. Wang, X.F., Harnefors, L., Blaabjerg, F.: Unified impedance model of grid-connected voltage-source converters. IEEE Trans. Power Electron. 33(2), 1775-1787 (2018) https://doi.org/10.1109/TPEL.2017.2684906
  29. Hu, Q., Fu, L., Ma, F.: Large signal synchronizing instability of PLL-based VSC connected to weak AC grid. IEEE Trans. Power Syst. 34(4), 3220-3229 (2019) https://doi.org/10.1109/TPWRS.2019.2892224
  30. Zhao, J., Huang, M., Yan, H.: Nonlinear and transient stability analysis of phase-locked loops in grid-connected converters. IEEE Trans. Power Electron. 36(1), 1018-1029 (2021) https://doi.org/10.1109/TPEL.2020.3000516
  31. Dong, D., Wen, B., Boroyevich, D.: Analysis of phase-locked loop low-frequency stability in three-phase grid-connected power converters considering impedance interactions. IEEE Trans. Ind. Electron. 62(1), 310-321 (2015) https://doi.org/10.1109/TIE.2014.2334665
  32. Rodriguez, P., Pou, J., Bogas, J.: Decoupled double synchronous reference frame PLL for power converters control. IEEE Trans. Power Electron. 22(2), 584-592 (2007) https://doi.org/10.1109/TPEL.2006.890000