Abstract
The Smart Vehicle-to-Grid Project at INESC TEC is currently studying the application of matrix converters to implement an isolated bidirectional AC-DC power converter using a single power conversion stage to provide a high-frequency link between the grid and vehicle. The single-stage structure and bidirectional power flow make the matrix converter an attractive solution for the charging applications of electric vehicles. A very brief overview of the matrix converter and its modulation strategy is presented, followed by detailed analysis. The power conversion system performance is investigated in terms of the switching commutation, input filter and input power factor. Simulations and experimental results of a prototype are also presented to further validate the proposed topology and operating principle.

Abstract
In this paper, a proposal for an ancillary services (AS) market framework addressing voltage control in multi-microgrid systems is presented. This var market proposal for MV distribution systems can be adopted to involve Distributed Generation (DG) units and microgrids in AS provision. In the approach that was developed each player is given the opportunity to submit its bid to the var market and the market settlement is performed using an Optimal Power Flow (OPF) formulation in order to minimize the price of reactive power purchased by the Distribution System Operator (DSO). This market is based on var capacity use and runs daily after the scheduling of the generation units for a period of operation of one clay.

Abstract
This paper investigates small-signal stability and decentralized control design for distribution electric energy systems with a large penetration of distributed generators. Two real world distribution systems are studied in this paper. The first system is the IEEE 30-node distribution system and the second one is the distribution system on Flores Island, one of the western group islands of the Azores Archipelago. The Block Gerschgorin Theorem and Liapunov function-based stability criteria are applied to formally state sufficient conditions for small-signal stability. The results illustrate that when the governor control of distributed generators is designed without considering interactions between generators, small-signal instability could occur in the system and even the sufficient conditions for stability would not be satisfied. In the next step, the paper assesses control design to stabilize potentially unstable distribution systems. The main focus is on designing enhanced decentralized control based on the introduced stability criteria. The findings illustrate that implementing the enhanced decentralized control could ensure stability and support a large penetration of distributed generators.

Abstract
This paper highlights findings of the European Commission funded project called MERGE (Mobile Energy Resources in Grids of Electricity). MERGE is a collaborative research project that includes utilities, regulators, commercial organisations and universities with interests in the power generation, automotive, electronic commerce and hybrid and electric vehicle sectors across the entire European Union (EU). This major two-year research initiative began in January 2010. The MERGE project mission is to evaluate the impacts that electric vehicles (EV) will have on the European Union (EU) electric power systems with regards to planning, operation and market functioning. The focus is placed on EV and SmartGrid/MicroGrid simultaneous deployment, together with renewable energy increase, leading to CO2 emission reduction through the identification of enabling technologies and advanced control approaches. In this paper indicative results from the impact of the additional EV load will have in the daily and yearly system load diagrams and in the operation of the transmission and distribution networks of five European countries (Greece, UK, Spain, Portugal, and Germany) in 2020 are presented. General conclusions are drawn.

Abstract
In this contribution international experiences concerning the integration of electrified cars (e-cars) into the grid in particular when there is a high penetration of renewable energies are presented. Future shortage of fossil fuels and concerns about security of supply derived the idea of electrified mobility which requires a new approach to design a complex system for future transportation. This system will be based on existing infrastructures (electricity system, road infrastructure, etc.) but it can also partially be considered as a "green field" approach. In the paper new strategies and global trends in the development of an e-mobility system will be presented, including strategies to combine the power system with the information and communication systems as well as a logistics. Practical experiences and data based on few projects e.g. Harz.EE-Mobility in Germany. European research as well as industry projects with these aims will be introduced and results will be presented. The main focus is twofold: integrating the upcoming mobile loads into the grid and likely storage possibilities that can operate bidirectional within the power grid. Simulations show that single-phase charging (3.7 kW) in the low and medium voltage grid does not lead to grid situations that require any significant adjustments in the power network regarding the loading of the assets. However, uncoordinated single-phase charging could create significant voltage deviations due to unbalanced loading of the three-phase low voltage grid. The different phases influence each other in unbalanced situations, through the common neutral conductor. These effects can already occur at low market penetration levels, due to the presence of local penetration levels being significantly higher than the average market level. For a significant amount of e-cars and high power charging (up to 22 kW in Germany) after 2020 the main concerns of investigation will be the forecasting of the requested charging power, the location of this demand and the impact on power grid operation security without active grid control (e.g. voltage, asset overloading). On the low-voltage grid Further, a full integration of renewable generation is also important as the amount of thermal power plants decrease, because they currently balance the intermittent, renewable generation. The future integration of e-cars into the power grid and the coordinated operation/charging with renewable energies (mobile electricity storage) will be one of the most important challenges. The conflict between mobility and the availability of storage capacity in contrast to the generation will be discussed and some recommendations based on the modeling and simulations will be presented in the paper, too.

Abstract