Abstract
This paper describes technical solutions to be adopted by Electric Vehicles (EV) battery grid interfaces, in order to get the provision of ancillary services to the grid. The developed solution exploits an EV battery charge control approach based in a grid cooperative response to frequency and/or voltage deviations. To be effective, those cooperative actions must result from both centralized/coordinated commands and local/individual EV charger response to the grid behaviour. In a scenario characterized by a massive deployment of EV, the adoption of such a solution allows an improvement on the power system dynamic behaviour, namely in small island grids. ©2010 IEEE.

Abstract
This paper describes a statistical approach developed for assessing the impacts resulting from EV presence in a given electricity network was developed. The algorithm, developed for this purpose, is based on a Monte Carlo method and can be seen as a planning tool that allows obtaining average values for several system indexes, like buses voltages, branches loading and energy losses. Additionally, it also allows identifying the most critical operation scenarios and the network components that are subjected to more demanding conditions and that might need to be upgraded. The example of a small grid from one of the Azores islands, Flores Island, was used for illustration purposes and two scenarios of EV integration were considered: 25% and 50% of the current light vehicles fleet replaced by EV. ©2010 IEEE.

Abstract
In this study, the authors analyse the social welfare impact of the integration of Portugal and Spain in the Iberian electricity market (MIBEL), taking into account the CO(2) price for emissions trading. They model the impact of emissions trading on the daily clearing prices and generation scheduling, and its effects on the benefits of integration as a whole. They compare the impact of market integration in Portugal and Spain and show that the welfare impact of the MIBEL is dependent on the CO(2) prices. From their analysis, they conclude high CO2 prices lead to a change in the merit order. Moreover, natural gas is the generation technology that most benefits from transmission constraints and from high CO(2) prices, as in the base case it is mainly used as a peak technology. The authors have also found that increases in the CO(2) prices do not lead to higher profits. Overall, the introduction of the MIBEL will increase social welfare by reducing generation costs and prices.

Abstract
In the scope of a recently launched European Research Project, a team of experts from public laboratories and TSO is in charge of defining the concepts and methodological approaches to design and analyse the technical and economic feasibility of future HVDC grids. This work aims at identifying, assessing and comparing several possible HVDC network topologies, with appropriate control and protection schemes, able to collect wind energy on large areas, transmit it at the best points to the AC grid and provide the necessary ancillary services for optimising the DC / AC interconnection in normal and disturbed conditions. The methodology adopted for the study and presented in this paper will focus on three main items: 1. identify and assess the economic drivers for the development of off-shore HVDC networks 2. identify the requirements for an optimal operation of the AC / DC interconnected power systems under normal and emergency conditions 3. conceptualise the coordinated control / command and protection plans for HVDC networks This paper gives a comprehensive view of the issues and tasks to be addressed during the run of the project.

Abstract
This paper presents a methodology for evaluating the impact resulting from the expected large scale integration of micro-generation (µG) in Low Voltage (LV) grids in Portugal. The proposed methodology allows the evaluation of the impacts in the entire LV and Medium Voltage (MV) distribution network by using typical load and generation profiles (24 hours) representing two well defined year periods (Summer and Winter). The simulations were performed in a time interval from 2008 to 2030, upon the definition of future scenarios related to the expected µG installed power in Portugal in the same period. Based on the obtained results, it was possible to quantify percentage gains related to the reduction of energy losses as a result of µ G integration in LV networks, avoided CO2 emissions and the possibility of achieving investment deferrals due to branches' congestion levels reduction or voltage profile improvements. ©2010 IEEE.

Abstract
This paper introduces several different indices in order to characterize the voltage stability of a power system. Voltage instability is a phenomenon which often contributes to the development of power system disturbances. Therefore, is very important to know how a power system is close to voltage collapse. The feasibility of the reported methods is shown by numerical studies in IEEE 57 bus test system. The simulation results are in close agreement.