Abstract
This paper results from the research conducted by the first author during the preparation of his MSc Thesis. This research aimed at investigating the impact on the market prices of the Iberian Electricity Market, MIBEL, due to increases of the feed-in generation, as such an increase is expected to occur in the next few years, namely for PV systems. This research was conducted using real market data publicly available in the web site of the Iberian Market Operator for 2016. To estimate this impact, for each trading hour of 2016 we considered new segments at price 0,0 (sic)/MWh to translate the priority given to this type of generation. These segments representing the new feed-in generation were then used together with the selling bids submitted by market agents to build the new aggregated selling curve. The new market price was finally obtained as the intersection of the new selling curve with the original buying curve, that was assumed unchanged. The global result indicates that if the feed-in generation increases by 25% regarding the values of 2016, then the average annual market price decreases by 6,57 % regarding the original value of 39,42 (sic)/MWh.

Abstract
Most generation expansion planning (GEP) methodologies developed under the monopolistic power industry framework were based on optimization models considering static and detailed descriptions of the power system's equipment and operating conditions. Many of these techniques are still in use in the current market framework, although planning in a liberalized environment is affected by a set of uncertainties and dynamics that traditional models are not designed to capture. In this setting, this research describes a GEP approach that uses System Dynamics (SD) to construct a simulation tool to provide planners, regulators, policy and decision makers with strategic and broader insights regarding policies to apply to power systems. The developed tool models the four Brazilian electricity submarkets, providing electricity prices and expansion scenarios in each region, given that policies recently applied at a country level are leading to different outcomes in each of these submarkets.

Abstract
This paper reports the main results obtained by the first author in the preparation of his MSc Thesis. The motivation for this work resulted from the intention announced by the Portuguese Regulatory Agency for the Energy Services to introduce dynamic tariffs as a way to induce a change of the behavior of some consumers in terms of moving some demand from peak periods to the adjacent hours. This is reported to lead to loss reductions, postponement of grid investments and generation cost reductions. In the case of Portugal, given the participation in the common market with Spain, generation costs are not publicly available so that it was investigated how the Social Welfare Function, SWF, that is maximized by the market operator would change given these demand transfers. The simulations were done using real market data for 2016 and the results suggest that the advantages are unclear since the SWF would be almost unchanged or slightly reduced.

Abstract
This paper presents a new modulation and control strategies for the high-frequency link matrix converter (HFLMC). The proposed method aims to achieve controllable power factor in the grid interface as well as voltage and current regulation for a battery energy storage device. The matrix converter (MC) is a key element of the system, since it performs a direct ac to ac conversion between the grid and the power transformer, dispensing the traditional dc-link capacitors. Therefore, the circuit volume and weight are reduced and a longer service life is expected when compared with the existing technical solutions. A prototype was built to validate the mathematical analysis and the simulation results. Experimental tests developed in this paper show the capability of controling the grid currents in the synchronous reference frame in order to provide grid services. Simultaneously, the battery current is well regulated with small ripple, which makes this converter ideal for battery charging of electric vehicles and energy storage applications.

Abstract
This paper addresses the dynamic stability analysis of an islanded power system regarding the installation of a reversible hydro power plant for increasing renewable energy integration. Being a high-head facility, the hydro power plant consists of separated pumps and turbines (Pelton type). In order to properly support the identification of hydro pumps connection requirements and the technology to be used, different options were taken into consideration, namely: fixed speed pumps coupled to induction machines directly connected to the grid and adjustable speed pumps supplied by a drive system. Extensive numerical simulations of the power system's dynamic behaviour response allowed the evaluation of the hydro power plant's role for the purpose of grid stability conditions. These simulations showed that the high head hydro power installation provides a marginal contribution to system frequency regulation when explored in turbine operation mode, leading to a reversible power station with a single penstock. Moreover, due to the significant additional system load introduced by the hydro pumping units, the obtained results clearly indicate that supplementary regulation flexibility is required to attend the need of assuring the stable operation of the system in case of critical disturbances such as grid faults. The study case demonstrates that, although the foreseen operation of a reversible hydro power plant creates new security challenges to overcome in an autonomous power system, robust technical solutions can be identified without increasing, from the local system operator's perspective, the operation complexity of the power system.

Abstract
In this article, we present a holistic framework for the integration of electric vehicles (EVs) in electric power systems. Their charging management and control methodologies must be optimized to minimize the negative impact of the charging process on the grid and maximize the benefits that charging controllability may bring to their owners, energy retailers, and system operators. We have assessed the performance of these methods initially through steady-state computational simulations, and then we validated them in a microgrid (MG) laboratory environment.