Abstract
Under normal operating conditions, a MicroGrid is interconnected with the medium voltage network; however, in order to deal with black start and islanded operation following a general blackout, an emergency operation mode must be envisaged. A sequence of actions and conditions to be checked during the restoration stage are identified and tested through numerical simulation. Voltage and frequency control approaches, inverter control modes, and the need of storage devices are addressed in this paper in order to ensure system stability, achieve robustness of operation, and not jeopardize power quality during service restoration in the low voltage area.

Abstract
The present paper describes an optimization strategy, to be adopted at the wind park control level, especially for those with large power output, that allow to define the commitment of the wind turbines and their active and reactive set points following requests from the wind park dispatch centers, assuming that individual wind turbines short term wind power forecasts are known and are expressed as power availability. This approach was also developed with a concern on the minimization of the connection / disconnection of the individual wind generators, for a given time horizon, and takes also into account restrictions in the limits for reactive power generated at the wind turbines.

Abstract
The present work investigates the dynamic behaviour of a mixed system consisting of a wind farm and a diesel group supplying a load, under different disturbances. In this regard, dynamic models and control systems that enable the generation part to support the grid are needed. The objective of this work has been also the implementation of the diesel group model and its afferent control system into Matlab-Simulink and to demonstrate their use by evaluating the response in time of the electric parameters.

Abstract
Large deployment of MicroGrids will have a considerable impact on the future operation of the electrical networks and will greatly influence the power system dynamics mainly at the Medium Voltage (MV) level whenever the upstream system has been lost. In dynamic studies the whole power system cannot be represented in a detailed manner because the huge system dimension would require a very large computational effort Therefore dynamic equivalents for MicroGrids need to be derived. The proposed approach is based on system identification theory for developing dynamic equivalents for MicroGrids, which are able to retain the relevant dynamics with respect to the existing MV network.

Abstract
This paper presents a new hierarchical approach to deal with the problem of controlling frequency and active power generation of a medium voltage network comprising several microgrids and distributed generation sources operated in islanded mode. The hierarchical approach described here should be cost effective and capable of dealing with large numbers of distributed microsources and performing tasks related to coordinated frequency control.

Abstract
This paper describes a new approach for the dimensioning and location of STATCOMs in Grids with large scale integration of wind energy. The approach developed uses as criterion the reduction of the loss of wind generation due to the operation of under voltage relays following a grid disturbance. The methodology adopted exploits Simulated Annealing in the identification of the problem solution. The approach has been tested in Iberian electrical system and results obtained show also its effectiveness regarding the global dynamic behaviour of the system.