Modelling and comparison analysis of grid‐connected DFIG‐based wind farm in weak grid. Issue 13 (14th September 2020)

• Record Type: Journal Article
• Authors: Yan, Cai; Yao, Wei; Wen, Jianfeng; Fang, Jiakun; Ai, Xiaomeng; Wen, Jinyu
• Is Part Of: IET renewable power generation. Volume 14:Issue 13(2020)
• Page Start: 2406
• Page End: 2415
• Publication Date: 2020-09-14
• Subjects: stators -- power generation control -- wind power plants -- rotors -- asynchronous generators -- shafts -- eigenvalues and eigenfunctions -- phase locked loops; grid‐connected DFIG‐based wind farm -- weak grid -- modelling comparison analysis -- grid‐connected double‐fed induction generator -- linear system analysis -- PLL dynamics -- eigenvalue analysis; Renewable energy sources -- Periodicals; 333.79405
• DOI: 10.1049/iet-rpg.2019.1382
• Languages: English
• ISSNs: 1752-1416

Abstract

Abstract : This study proposes a generic method for modelling and comparison analysis of grid‐connected double‐fed induction generator (DFIG)‐based wind farms in a weak grid. A detailed model of DFIG in a weak grid is established and used as a benchmark. Specifically, the detailed model consists of the mechanical part, generator part, rotor side converter, and phase‐locked loop (PLL). Two simplified models of grid‐connected DFIG‐based wind farms in a weak grid are compared with the detailed model to investigate the mechanism of sub‐synchronous oscillation (SSO) as well as the influential factors through linear system analysis. The first simplified model ignores shafting dynamics, stator flux dynamics, and PLL dynamics. The same assumptions are used in the latter, except that PLL dynamics are considered. Time‐domain simulation and eigenvalue analysis are used to verify the accuracy of the simplified models. The block diagrams of the linearised system are derived based on the proposed model, and the oscillation mechanism is explained by linear system analysis. Through eigenvalue analysis and the root locus method, the influences of the parameters of the DFIG and its controllers on the system stability are identified and analysed.