Fundamental impedance identification method for grid‐connected voltage source inverters. Issue 5 (1st May 2014)

• Record Type: Journal Article
• Authors: Sun, Xiaofeng; Chen, Jingxian; Guerrero, Josep M.; Li, Xin; Wang, Liqiao
• Is Part Of: IET power electronics. Volume 7:Issue 5(2014)
• Page Start: 1099
• Page End: 1105
• Publication Date: 2014-05-01
• Subjects: distributed power generation -- identification -- invertors -- reactive power control -- stability; fundamental impedance identification method -- grid‐connected voltage source inverters -- line fundamental impedance -- point of common coupling -- PCC -- microgrids -- droop coefficient regulation -- power sharing -- stability improvement -- multidistributed generation system -- constant power control strategy -- active powers -- reactive powers -- grid‐connected mode -- online real‐time calculation capability -- scaled laboratory prototype; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2013.0398
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : Considering the importance of line fundamental impedance from the inverter to the point of common coupling (PCC) in microgrids, this study analyses the influence of fundamental impedance on system stability. Line fundamental impedance values not only apply to decoupled droop control, which can realise accurate control between active and reactive power, but also regulate the droop coefficient to eliminate system circulation, realise power sharing and improve system stability when a multi‐distributed generation system operates in parallel. Moreover, the PCC can sense grid fault on the basis of variations in fundamental impedance. A novel fundamental impedance identification method that adopts a constant power control strategy by varying the active and reactive powers in the grid‐connected mode is proposed. In addition, the proposed method has online real‐time calculation capability. This strategy has been tested in simulation and in experiments by using a scaled laboratory prototype. Simulation and experimental results verify the accuracy of the proposed scheme.