Simple synchronisation technique for three-phase grid-connected distributed generation systems

• Published in: IET renewable power generation Vol. 7; no. 1; pp. 55 - 62
• Main Authors: Guo, Xiao-Qiang, Wu, Wei-Yang
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.01.2013; The Institution of Engineering & Technology
• Subjects: auxiliary unit; dc offset; distributed power generation; eigenvalue analysis; eigenvalues and eigenfunctions; fixed‐point TMS320F2812 DSP; fundamental positive sequence component estimation; grid synchronisation technique; negative sequence estimation; parameter tuning guidance; power filters; power grids; real‐complex‐coefficient filters; Renewable energy sources; three‐phase grid‐connected distributed generation systems; word length 32 bit; fixed-point TMS320F2812 DSP; negative sequence estimation; renewable energy sources; grid synchronisation technique; auxiliary unit; distributed power generation; eigenvalues and eigenfunctions; power filters; word length 32 bit; parameter tuning guidance; real-complex-coefficient filters; three-phase grid-connected distributed generation systems; word length; dc offset; power grids; eigenvalue analysis; fundamental positive sequence component estimation
• ISSN: 1752-1416; 1752-1424; 1752-1424
• DOI: 10.1049/iet-rpg.2011.0243

Grid synchronisation is crucial for integration of renewable energy sources and distributed generation systems into the grid. Accurate and fast estimation of the fundamental positive sequence component is a necessity for synchronisation of three-phase distributed generation systems with the grid. In this study, a simple synchronisation technique based on the real-complex-coefficient filters is proposed. It has a very simple structure, and can directly estimate the fundamental positive and negative sequences under the distorted, unbalanced and offset conditions with no need of a phase-locked loop. Furthermore, the dc offset can also be extracted precisely. For optimising the steady-state and dynamic performance, a parameter tuning guidance is provided from the eigenvalue analysis point of view. In addition, a simple auxiliary unit is presented to remain its frequency-adaptive feature. Finally, experimental results based on a 32-bit fixed-point TMS320F2812 DSP verify the effectiveness of the proposed synchronisation method.