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Wind farms can be analyzed using state estimation methods, which can be used to obtain its running state, including several aspects that cannot be easily obtained using other methods (e.g., capacitor bank aging) Using these methods on these types of networks is strongly affected by decoupling between active and reactive power and by a radial configuration, which is typical. For example, this decoupling affects its observability and robustness as well as the technical feasibility of the results. To overcome these drawbacks, an extended state estimation method is proposed in which the models for the different wind turbine technologies have been incorporated. These models have been mainly generated from measurement data using neural networks and polynomial fitting; these models do not require parameter values, which are rarely available from manufacturers. Furthermore, the resulting equations for modeling wind turbines are easily integrated into the state estimator due to their simplicity and derivatives.Thus, a method that guarantees feasible results, at least for wind turbines, was generated with increased observability robustness. The method was tested using measurement data from the Sotavento Wind Park, which has wind turbines with different types of technologies. [ABSTRACT FROM AUTHOR]

Fixed-speed wind generator (FSWG) technology has an important presence in countries where wind energy started to be developed more than a decade ago. This type of technology cannot be directly adapted to the grid codes, for example those requirements related to the immunity level under voltage dips. That behavior is typically referred as low-voltage ride through (LVRT), and it usually implies certain reactive and active power injection requirements, both during a voltage dip and during the voltage recovery. In this context, a review is presented of the LVRT exigencies present in some of the countries with the most advanced grid codes (Denmark, Germany, Spain and the United Kingdom). In this paper, the capabilities of STATCOM-based devices for fulfilling the LVRT requirements in FSWGs are analyzed. For this purpose, two technologies are considered: a STATCOM with a supercapacitor, which improves its energy storage features; and a STATCOM with a supercapacitor and a DC-DC converter, to achieve higher discharge levels. [ABSTRACT FROM AUTHOR]

The Weibull probability density function (PDF) has mostly been used to fit wind speed distributions for wind energy applications. The goodness of fit of the results depends on the estimation method that was used and the wind type of the analyzed area. In this paper, a study on a particular area (Galicia) was performed to test the performance of several fitting methods. The goodness of fit was evaluated by well-known indicators that use the wind speed or the available wind power density. However, energy production must be a critical parameter in wind energy applications. Hence, a fitting method that accounts for the power density distribution is proposed. To highlight the usefulness of this method, indicators that use energy production values are also presented. [ABSTRACT FROM AUTHOR]