A Novel Pre-Synchronization Control for Grid Connection of Virtual Synchronous Generator

• Published in: Elektronika ir elektrotechnika Vol. 26; no. 6; pp. 25 - 31
• Main Authors: Chen, Xuhai, Zhang, Yiwang, Dong, Jiqing, Mao, Xingkui, Chen, Jiaqiao, Wen, Buyin, Zhang, Zhe
• Format: Journal Article
• Language: English
• Published: Kaunas University of Technology, Faculty of Telecommunications and Electronics 01.12.2020; Kaunas University of Technology
• Subjects: droop control; energy storage; pre-synchronization control; virtual synchronous generator (vsg); China
• ISSN: 1392-1215; 2029-5731
• DOI: 10.5755/j01.eie.26.6.25874

The virtual synchronous generator (VSG) introduces rotational inertia and damping through the droop control to take part in frequency regulation of the grid. By building the VSG model, the VSG controller, including both the frequency controller and the excitation controller, are analysed and designed. The analysis shows that the large phase difference Δθ between the VSG voltage and the grid voltage at the grid-tied moment may produce large power and damage the VSG. The proposed pre-synchronization control minimizes the phase difference, which is implemented by replacing Δθ with sinΔθ to avoid any step change from Δθ. The proposed method is able to simplify control, shorten pre-synchronization tracking time, and achieve high accuracy without a phase-lock loop. The built 12 kW VSG simulation and prototype verify the theoretical analysis, the proposed control and its associated design.