Abstract
This paper presents an adequacy and security evaluation of electric power distribution systems with distributed generation. For this accomplishment, bulk power system adequacy and security evaluation concepts are adapted to distribution system applications. The evaluation is supported by a combined discrete-continuous simulation model which emulates the distribution system operation. This model generates a sequence of operation states which are evaluated from a steady-state perspective using AC power flow computations. Frequency and voltage stability are also assessed using dynamic simulation in order to verify the feasibility of islanded operation. Simulation results are presented for the RBTS-BUS2-F1 as well as an actual feeder from the South of Brazil. The results emphasize the need to consider adequacy and security aspects in the distribution system assessments, mainly due to the ongoing integration of distributed energy resources.

Abstract
This paper proposes a control scheme that allows doubly fed induction wind generators (DFIWG) to participate effectively in system frequency regulation. In this control approach, wind generators operate according to a deloaded optimum power extraction curve such that the active power provided by each wind turbine increases or decreases during system frequency changes. The control strategy defined at the wind generator to supply primary frequency regulation capability exploits a combination of control of the static converters and pitch control, adjusting the rotor speed and the active power according to the deloaded optimum power extraction curve. Results obtained in a small isolated system are presented to demonstrate the effectiveness of the approach.

Abstract
This paper addresses the problematic of operating isolated networks with large penetration of intermittent renewable power sources, as well as the benefits that electric vehicles might bring to these systems. A small island's network was used as case study and a 100% renewable dispatch for a valley period, only with hydro and wind generation, was tested in a dynamic simulation platform developed in Eurostag. Two distinct wind speed disturbances were simulated and, for both, the impact in the network's frequency was evaluated considering two different situations: electric vehicles only in charging mode and electric vehicles participating in primary frequency control. It was assumed the existence of 575 electric vehicles in the island. The impact of having electric vehicles performing primary frequency control in the expected batteries state of charge was also evaluated. © 2011 IEEE.

Abstract
This paper describes a research developed to identify management procedures to deal with the charging of Electric Vehicles (EVs) batteries in scenarios characterized by a large scale deployment of this new kind of load. Three approaches were studied: dumb charging, dual tariff policy and smart charging. To assess the efficacy of such procedures, the grid integration of EVs was pushed to its limit for each of the adopted charging management approaches. A Medium Voltage (MV) grid, representative of a residential area distribution grid in Portugal, was used as testing environment. Several shares of EVs technologies were considered for different integration scenarios. Voltage profiles and branch congestion levels were evaluated, for the peak load hour, for grid technical limits checking. Losses were also evaluated for a typical daily load profile.

Abstract
Portugal is committed towards the EU to an ambitious target of attaining 39% of renewable energy production by 2010, as defined in the RES Directive. The new big hydroelectric investments, together with the mini-hydro power stations that are expected to be ready until 2010 will not be able to increase largely this share of needed renewable energy. The missing renewable energy should be produced exploiting wind energy, meaning that by 2010 a wind power capacity of more than 4.000 MW should to be in operation. At the same time Spain is also increasing wind power integration, such that by 2010 more than 13.000 MW are expected to be installed. The Spanish and the Portuguese electric power systems are facing at the same the challenge of a regional electricity market - the Iberian Electricity Market. This requires that wind power integration must be tackled having in mind technical and commercial concerns.

Abstract
This paper presents an optimization strategy to be adopted at wind park control level. This approach transposes the classical formulations of a unit commitment and a generator dispatch problem to the turbines of a wind park, assuming that variable speed wind turbines are installed, and considering that wind speed forecasts are available. Wind speed forecasts, demands from grid operators or generation levels defined to comply with market strategies are the inputs of the problem. A small example is used to illustrate the proposed approach.