Power Grid Impedance Measurement Method Based on Sobol Quasi-random Pulse Width Modulation

被引：0
|
作者：
Du Y. [1 ,2 ]
Wu H. [1 ,2 ]
Yang X. [1 ,2 ]
Jiang W. [1 ,2 ]
Su J. [1 ,2 ]
机构：
[1] School of Electrical and Automation Engineering, Hefei University of Technology, Hefei
[2] Research Center for Photovoltaic System Engineering of Ministry of Education, Hefei University of Technology, Hefei
来源：
Dianli Xitong Zidonghua/Automation of Electric Power Systems | 2021年 / 45卷 / 02期
关键词：
Broadband impedance; Grid-connected inverter; Impedance measurement; Pulse width modulation; Sobol sequence; Stability;
D O I：
10.7500/AEPS20200225010
中图分类号：
学科分类号：
摘要：
The real-time power grid impedance information obtained by grid-connected inverters can be used in power grid status monitoring, fault diagnosis, and grid-connected equipment stability control, to improve the intelligent level of grid-connected equipment and power grid regulation. Since the injected disturbance signal is often applied to the current control loop of the inverter, the impedance measurement frequency band is limited by the bandwidth of the controller. In order to improve the accuracy of high-frequency impedance measurement, this paper proposes a power grid impedance measurement method based on Sobol quasi-random pulse width modulation (SQRPWM) by taking advantages of the characteristic of the frequency spectrum shift of random pulse width modulation and the uniformity of Sobol quasi-random sequences. The frequency boundary of SQRPWM is optimized and designed according to the system bandwidth and stability constraints. The feasibility of the proposed impedance measurement scheme based on SQRPWM and the mixed impedance measurement scheme combined with the single pulse and SQRPWM is verified on the experimental platform of Starsim. The results show that the proposed impedance measurement scheme has the advantages of small disturbance and high measurement accuracy in a high frequency band. Moreover, if the proposed method is combined with the current-disturbance based impedance measurement method, the frequency band of the power grid impedance measurement can be further expanded and the broadband impedance information can be obtained. © 2021 Automation of Electric Power Systems Press.
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页码：148 / 156
页数：8
相关论文
共 26 条
  • [1] TAUL M G, WANG Xiongfei, DAVARI P, Et al., Grid synchronization of wind turbines during severe symmetrical faults with phase jumps, IEEE Energy Conversion Congress and Exposition (ECCE), pp. 38-45, (2018)
  • [2] KHALFALLA H, ETHNI S, SHIREF M, Et al., Grid impedance estimation for single phase PV grid tide inverter based on statistical signal processing techniques, 53rd International Universities Power Engineering Conference (UPEC), (2018)
  • [3] ALVES D K, RIBEIRO R L A, COSTA F B, Et al., Real-time wavelet-based grid impedance estimation method, IEEE Transactions on Industrial Electronics, 66, 10, pp. 8263-8265, (2019)
  • [4] WANG Hui, LIU Wei, LI Qunzhan, Et al., Responsibility distinction for multiple harmonic sources based on partial least square in complex field and equivalent method, Automation of Electric Power Systems, 41, 4, pp. 78-85, (2017)
  • [5] HOFFMANN N, FUCHS F W., Minimal invasive equivalent grid impedance estimation in inductive-resistive power networks using extended Kalman filter, IEEE Transactions on Power Electronics, 29, 2, pp. 631-641, (2014)
  • [6] TIMBUS A V, TEODORESCU R, BLAABJERG F, Et al., Online grid impedance measurement suitable for multiple PV inverters running in parallel, IEEE 21st Applied Power Electronics Conference and Exposition (APEC), (2006)
  • [7] CAI W, LIU B, DUAN S, Et al., An islanding detection method based on dual-frequency harmonic current injection under grid impedance unbalanced condition, IEEE Transactions on Industrial Informatics, 9, 2, pp. 1178-1187, (2013)
  • [8] LIU Chen, ZHAO Jinbin, WANG Shanshan, Et al., A line impedance identification based on single pulse injection in DC microgrid, Transactions of China Electrotechnical Society, 33, 11, pp. 2584-2591, (2018)
  • [9] DOU Qingyun, ZENG Liu, LIU Jinjun, Et al., A novel impedance measurement method for three-phase power electronic systems, 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia), pp. 2282-2287, (2015)
  • [10] YUE Xiaolong, ZHUO Fang, Injected current perturbation signal form for impedance measurement based on superposition method and sinusoidal amplitude modulation, Journal of Power Supply, 3, pp. 8-13, (2014)
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