Stability Control of LCL-type Grid-connected Inverter Based on Capacitor Voltage Full Feedforward Under Weak Grid Condition

被引：0
|
作者：
Duan X. [1 ]
Li P. [1 ]
Zhao F. [2 ]
Chen S. [1 ]
Wang J. [1 ]
机构：
[1] School of Automation, Beijing Information Science and Technology University, Beijing
[2] Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing
来源：
Gaodianya Jishu/High Voltage Engineering | 2022年 / 48卷 / 06期
基金：
中国国家自然科学基金;
关键词：
amplitude margin; full feedforward of capacitor voltage; grid-connected current delay cascade feedback; phase angle margin; stability control; weak grid;
D O I：
10.13336/j.1003-6520.hve.20211586
中图分类号：
学科分类号：
摘要：
Under the condition of weak grids, background harmonics may impair the grid-connected power quality with the LCL-type grid-connected inverter, and this type inverter system instability can be easily caused by grid impedance fluctuation. Consequently, we put forward a grid-connected current delay cascade feedback control strategy based on full feedforward capacitor voltage of LCL filter. The capacitor voltage full feedforward is adopted to suppress the influence of grid voltage distortion on grid-connected current, a pure delay feedback link of the grid-connected current is introduced to improve the phase angle stability margin, and the proportional delay link cascaded with the pure delay is equivalent to active damping to improve the amplitude stability margin of the LCL grid-connected inverter. The above-mentioned methods work together to adapt the resonant frequency of the LCL filter to be shifted in a wide range under the weak grid conditions. The test results of SIMULINK simulation and MT6020 experimental platform show that the grid-connected current delay cascade feedback control expands the stable range of resonant frequency offset of the LCL-type grid-connected inverter system under the weak grid condition, and improves the robustness of the inverter system. When the grid voltage is distorted, the full feedforward of capacitor voltage decoupled from stability control ensures the stable operation of the inverter under the conditions of high sinusoidal degree of grid-connected current, low harmonic distortion rate and high power factor. © 2022 Authors. All rights reserved.
引用
收藏
页码：2140 / 2153
页数：13
相关论文
共 21 条
  • [1] LIU Li, YU Jiali, Research of control strategy of grid connected PV inverter under asymmetric grid voltage, Acta Energiae Solaris Sinica, 38, 10, pp. 2848-2856, (2017)
  • [2] YANG Dongsheng, RUAN Xinbo, WU Heng, A virtual impedance method to improve the performance of LCL-type grid-connected inverters under weak grid conditions, Proceedings of the CSEE, 34, 15, pp. 2327-2335, (2014)
  • [3] YANG Ming, BAO Jingwen, SUN Yanzhou, Et al., Capacitor voltage feedforward control strategy of grid-connected inverter in weak grid, Acta Energiae Solaris Sinica, 42, 7, pp. 94-102, (2021)
  • [4] WU Yunya, XIE Shaojun, KAN Jiarong, Et al., A full grid voltage feed-forward control strategy with inverter-side current feedback for LCL grid-connected inverters, Proceedings of the CSEE, 33, 6, pp. 54-60, (2013)
  • [5] ZHANG H, RUAN X B, LIN Z H, Et al., Capacitor voltage full feedback scheme for LCL-type grid-connected inverter to suppress current distortion due to grid voltage harmonics, IEEE Transactions on Power Electronics, 36, 5, pp. 2996-3006, (2021)
  • [6] LIU Q Y, LI Y, HU S J, Et al., A transformer integrated filtering system for power quality improvement of industrial DC supply system, IEEE Transactions on Industrial Electronics, 67, 5, pp. 3329-3339, (2020)
  • [7] DONG Wenming, Research on the control of LCL-type grid-connected inverter under harmonic grid voltage condition, (2018)
  • [8] LISERRE M, TEODORESCU R, BLAABJERG F., Stability of grid-connected PV inverters with large grid impedance variation, Proceedings of the 2004 IEEE 35th Annual Power Electronics Specialists Conference, pp. 4773-4779, (2004)
  • [9] WANG Yuhong, YE Wei, SONG Ruihua, Et al., Design of additional active damping for three-phase LCL grid connected inverter based on impedance analysis method, High Voltage Engineering, 47, 8, pp. 2645-2654, (2021)
  • [10] CAO Ziheng, XIAO Xianyong, MA Junpeng, Et al., Novel capacitor current feedback active damping strategy for enhancing robustness of LCL-type grid-connected inverters, High Voltage Engineering, 46, 11, pp. 3781-3789, (2020)
123