In this paper, a preliminary analysis of the impact of high wind power penetration in the planning and operation of the Spanish power system is presented. The problems studied in the paper are those related to the stability of the power system. This key subject could be deeply influenced by the installation of up to 15,000 MW of wind power generation as it has been planned for the next six years. The analysis presented here is based on the results of dynamic simulations. Dynamic models of the induction generator (squirrel cage and doubly fed) and models of the wind farms have been developed to make possible the simulations. From the simulations results some conclusions and recommendations have been extracted, which would contribute to the appropriate integration of the new wind generation foreseen for the Spanish power system. Index Terms-Doubly fed induction generator, power generation control, power system stability, wind power generation.

Sphingolipids are abundant constituents of neuronal membranes that have been implicated in intracellular signaling, neurite outgrowth and differentiation. Differential localization and trafficking of lipids to membrane domains contribute to the specialized functions. In non-neuronal cultured cell lines, plasma membrane short-chain sphingomyelin and glucosylceramide are recycled via endosomes or sorted to degradative compartments. However, depending on cell type and lipid membrane composition, short-chain glucosylceramide can also be diverted to the Golgi complex. Here, we show that NBD-labeled glucosylceramide and sphingomyelin are transported from the plasma membrane to the Golgi complex in cultured rat hippocampal neurons irrespective of the stage of neuronal differentiation. Golgi complex localization was confirmed by colocalization and Golgi disruption studies, and importantly did not result from conversion of NBD-glucosylceramide or NBD-sphingomyelin to NBD-ceramide. Double-labeling experiments with transferrin or wheat-germ agglutinin showed that NBD-sphingolipids are first internalized to early/recycling endosomes, and subsequently transported to the Golgi complex. The internalization of these two sphingolipid analogs was energy and temperature dependent, and their intracellular transport was insensitive to the NBD fluorescence quencher sodium dithionite. These results indicate that vesicles mediate the transport of internalized NBD-glucosylceramide and NBD-sphingomyelin to the Golgi complex.