Robust Converter Synchronization to a Weak Grid Through a DFT-based Method

• Type: Article in International Conference Proceedings Book
• Date: 2006

Authors

António P. Martins (Author) FEUP; José C. Ferreira (Author) FEUP

Conference proceedings International

Title: Proceedings of the International Conference on Renewable Energy and Power Quality, ICREPQ'2006

Pages: 1-7

International Conference on Renewable Energy and Power Quality, ICREPQ'2006

Palma de Maiorca, Spain, 5-7 April 2006

Indexing

INSPEC

Scientific classification

FOS: Engineering and technology > Electrical engineering, Electronic engineering, Information engineering

CORDIS: Technological sciences > Engineering > Control engineering > Automation ; Technological sciences > Engineering > Electrical engineering

Other information

Abstract (EN): Phasor estimation and symmetrical components estimation is a fundamental task in power electronics converters control. Power conditioning systems like active filters, universal power flow controllers, static compensators, and dynamic voltage restorers, among other ones, need accurate synchronization circuits capable of dealing with very different grid voltage perturbations. Voltage sags and swells, harmonics, spikes and notches, frequency variation, phase steps, DC components and noise, are phenomena that can cause severe malfunction in the control or supervision circuits of such power systems. Additionally, some protection systems are sensitive to some of these parameters and can give wrong actions when they are not expected to. The DFT algorithm is one of best performers in phasor estimation, but is not perfect. The paper accurately describes the DFT errors under frequency variation, decaying DC components and harmonics, and analyzes the instantaneous phasor estimation, with absolute and recursive algorithms. Strong grid voltage perturbations, occurring in weak grids, especially in the grid connection of renewable energies, demand for a DFT-based robust estimation method. The proposed method, as demonstrated by extensive simulations, is capable of handling general grid voltage perturbations, imposing a compromise between dynamic response and accuracy.

Language: Portuguese

Type (Professor's evaluation): Scientific