Towards an overall simulator for a synchronous wind energy system

The amount of electrical energy obtained from renewable sources, specially wind energy, is rising quickly. The interface of this distributed generation with the electrical network will have soon an important influence on control, power quality and voltage stability issues of the whole energy net. In order to be prepared to that change it is necessary to simulate, with a sensible accuracy, the transient events, which happen during normal operation or during faults, and have influence in either net or inner variables. So in this way, it is important to model a wind energy system, taking into account every subsystem that have a significant influence over the transient behavior of the compound system. Some important and recent papers are oriented to analyze the stability [1] and the power quality of the wind systems [2]. In the first one, a doubly fed generator is analyzed from an electrical stability point of view; and in the second one the RMS values of the main electrical variables have been simulated in an overall wind energy system. An interesting paper describing the transient problems in relation with the grid integration of wind turbines can be seen in [3]. In this paper, as a preliminary design of an overall simulator, a variable speed system with a wound rotor synchronous generator is analyzed and a connection of the windmill with a variable wind is simulated.The authors are thankful to the support from the Caja de Ahorros del Mediterraneo (BECA-CAM predoctoral 2003, a grant conceded to the first author). This research is partially supported by the Consejeria de Educación y Ciencia de la Comunidad Autónoma de la Región de Murcia (Project Séneca 2002: PC-MC/3/00074/FS/02)