Evaluation of Power Quality in a Wind Power Generation System.

Nowadays, among the renewable energy sources, wind systems are more economic in compare with the others Variable speed wind systems deliver 20% to 30% more energy tan the constant power systems. Also they reduce the power oscillation and optimize the reactive power presentation. However, the connection of large wind farms to the grid may cause problems in terms of power quality due to the variability of the energy extracted from the wind. The mentioned power quality problems are generally taken into consideration after the grid integration of wind farms. This paper discusses on the grid impedance evaluation method at wind farm terminals. The non-intrusive method uses variations of the wind power production, and this permanent variability allows us to apply the source impedance identification process, assuring its assessment. New algorithms are developed taking as a reference the accurate GPS synchronized measurement of phase at a very stable power plant, to evaluate the source impedance at a wind farm point of common coupling (PCC) where complex variations of the voltage are expected. The instantaneous value of the grid impedance will, not only, allow assigning responsibilities but also will facilitate the design of equipments, network components, control systems tuning and protections configuration. The development of dispersed generation will be positively influenced by the capacity of measuring the network strength. [ABSTRACT FROM AUTHOR]