Abstract

The existing targets for wind power anticipate a considerable growth that will imply a high degree of wind power penetration in many countries. Besides, the worldwide picture, in terms of both installed wind power capacity and its geographic distribution, is evolving year by year. Thus, at the end of 2010, USA had 40 180 MW, Germany 27 214 MW, Spain 20 676 MW and China 42 287 MW. The aim of this project is the reinforcement of wind power integration in the power system. To do this, this proposal deals with the study of a variety of issues that are essential for the integration of very large amounts of wind power capacity in power systems:

    • Electricity production from wind power increases uncertainty in the power system operation, due both to variability of the wind and to relative reduction of manageable power plants that support the grid. To overcome this challenge, more flexibility in power systems will be required, but it also will be necessary to take full advantage of wind power plants potential for contributing to maintaining the balance within the grid (in terms of voltage and frequency).
    • In order to deal with maintenance of voltage levels, especially against network events such as voltage dips, experience of the researchers involved in this project, who have participated in the development of IEC 61400-27-1, currently subject to a vote, will be harnessed. This norm proposes standard models for wind turbines, which aim to reproduce as simply as possible the active and reactive power injected by the wind turbines during normal operation and facing some events. In this project, in addition to evaluating the use of such models by adjusting and comparing them with real data, an active participation in the development and application of this norm, as in the international committee —Electrotechnical Commission TC88— which is starting the searching and regulating of computational models of wind farms, that will be reflected in future norm IEC 61400-27-2, will be held.
    • Suggested wind farm models will be integrated into a platform which is able to simulate power systems with high wind penetration, so it is possible to assess the support of the wind generators for maintaining the voltage levels. To this end, different existing operating procedures in representative countries, as well as drafts or other possible procedures which are best suited to the type of power systems under study, will be implemented.
    • In the other hand, regarding the power system frequency, a debate on whether including or not a mandatory inclusion in future operating procedures of frequency response of wind turbines, has been started, looking for a higher proportion of wind energy in the system. There are currently several proposals, but positive effects of such control, the techniques to supply it in case a power increase is required and possible limitations or even involved drawbacks have not been yet evaluated.
    • This project aims, therefore, to propose different types of algorithms to provide primary frequency response, including emulation of inertia in variable speed wind turbines, as well as strategies to reduce the effects of wind variability in terms of reserve requirements or frequency response needed by the secondary control.
    • To this end, appropriate wind and wind farm models will be developed and integrated into power system models with high wind energy penetration but with different characteristics regarding the system inertia, damping factor of the connected loads, flexibility of conventional generation, existence of active mechanisms for demand management, etc…
    • Finally, all proposed control algorithms will be integrated into simple models of wind farms in a real time simulator of a power system, in order to evaluate the compatibility between all the algorithms, their computational costs, velocity, etc.
    • The researchers involved in this project are members of several national and international committees related to this subject. As stated in the document, some results will be presented and discussed in the Annex XXV of the International Energy Agency —“ Power System Operation with Large Amounts of Wind Power —”, the International Electrotechnical Commission (IEC) — IEC 61400-21, IEC 61400-27— and other initiatives —“ Wind —AEN/CTN206/SC88 AENOR turbines”— or the Spanish Wind Energy Association –.
  • Furthermore, this proposal has received the support of companies an entities by means of letters of interest —the Spanish Wind Energy Association, Gamesa Innovation and Technology, Iberdrola Renovables, EDP Renovables, Ineal, Rotonda Energy, Elecdey, and the energy agencies of the Spanish Regions of Castilla-La Mancha and Murcia—, providing as well active participation in the project.

    Finally, it must be noted that, from the researchers point of view, this proposal meets the main objectives of the 2008–2011 Spanish R&D and Innovation Plan, in terms of the internationalization of activities, dissemination of results, solution of technological and economical problems, while maintaining a critical mass of research groups —two Spanish Universities are involved: Universidad de Castilla-La Mancha and Universidad Politécnica de Cartagena, and collaborations of the prestigious research center U.S. National Renewable Energy Laboratory “ (NREL)”, as well as companies Gamesa Innovation and Technology and Energy to Quality, which contribute with their researchers—.