Abstract
The importance of price forecasting has gained attention over the last few years, with the growth of aggregators and the general opening of the European electricity markets. Market participants manage a tradeoff between, bidding in a lower price market (day-ahead), but with typically higher volume, or aiming for a lower volume market but with potentially higher returns (balance energy market). Companies try to forecast the extremes of revenues or prices, in order to manage risk and opportunity, assigning their assets in an optimal way. It is thought that in general, electricity markets have quasi-deterministic principles, rather than being based on speculation, hence the desire to forecast the price based on variables that can describe the outcome of the market. Many studies address this problem from a statistical approach or by performing multiple-variable regressions, but they very often focus only on the time series analysis. In 2019, the Loss of Load Probability (LOLP) was made available in the UK for the first time. Taking this opportunity, this study focusses on five LOLP variables (with different time-ahead estimations) and other quasi-deterministic variables, to explain the price behavior of a multi-variable regression model. These include base production, system load, solar and wind generation, seasonality, day-ahead price and imbalance volume contributions. Three machine-learning algorithms were applied to test for performance, Gradient Boosting (GB), Random Forest (RF) and XGBoost. XGBoost presented higher performance and so it was chosen for the implementation of the real time forecast step. The model returns a Mean Absolute Error (MAE) of 7.89 £/MWh, a coefficient of determination (R2 score) of 76.8% and a Mean Squared Error (MSE) of 124.74. The variables that contribute the most to the model are the Net Imbalance Volume, the LOLP (aggregated), the month and the De-rated margins (aggregated) with 28.6%, 27.5%, 14.0%, and 8.9% of weight on feature importance respectively.

Abstract
Demand Response (DR) systems are gaining momentum in the EU energy markets albeit based on fragmented standards that, as a result, hinder interoperability. These discrepancies necessitate the introduction of a semantically enriched umbrella framework that will allow DR systems to exchange and consume data transparently, an issue that is currently unaddressed. Furthermore, to support semantically interoperable DR architectures, a multi-layer compliance testing framework is required that will examine and quantify the technical, syntactic and semantic properties of individual DR systems. In this work, the aforementioned gaps in the literature are addressed by, first, introducing an OpenADR-based semantic enrichment component. According to the guidelines of the Smart Grid Architecture Model (SGAM) framework, a concrete evaluation procedure of this component is presented, which allows for a step-by-step syntactic and semantic testing. Following the identification of the instruments composing the testbed and the equipment/links under test at SGAM's communication and information layers, the Basic Application Interoperability Profiles (BAIOPs) are defined and their involved steps are described. Experiments demonstrate the validity of the presented methodology, while also evaluating the introduced component.

Abstract
Large-scale Battery Energy Storage System (BESS) capacity installed for stationary applications is rising in the first decades of 21st century. Business models related to BESS highly depend on BESS lifetime. BESS lifetime can be preserved only if accurate thermal management of the assets allows to keep it at design temperature. Auxiliary systems' needs for cooling and heating the BESS cannot be disregarded while modeling the real-world operation of these facilities. In this paper we propose an improved protocol for organic modeling of large-scale BESS grid-connected. We assess the share of losses and the operational efficiency related to the provision of ancillary services to the network by BESS in different seasons and different working conditions. We highlight that BESS efficiency increases in case the system is constantly exploited, avoiding time idle or at low power. The model proposed, with respect to standard techniques, allows to better represent BESS performance. Indeed, just by disregarding the losses related to thermal management of the assets (as it is for standard modeling techniques), errors committed are up to 10%.

Abstract
The digital terrain model (DTM), the representation of earth's surface at regularly spaced intervals, is the first input in the computational modelling of atmospheric flows. The ability of computational meshes based on high- (2 m; airborne laser scanning, ASL), medium- (10 m; military maps, Mil) and low-resolution (30 m; Shuttle Radar Topography Mission, SRTM) DTMs to replicate the Perdigao experiment site was appraised in two ways: by their ability to replicate the two main terrain attributes, elevation and slope, and by their effect on the wind flow computational results. The effect on the flow modelling was evaluated by comparing the wind speed, wind direction and turbulent kinetic energy using VENTOS (R)/2 at three locations, representative of the wind flow in the region. It was found that the SRTM was not an accurate representation of the Perdigao site. A 40m mesh based on the highest-resolution data yielded an elevation error of less than 1.4m and an RMSE of less than 2.5m at five reference points compared to 5.0m in the case of military maps and 7.6m in the case of the SRTM. Mesh refinement beyond 40m yielded no or insignificant changes on the flow field variables, wind speed, wind direction and turbulent kinetic energy. At least 40m horizontal resolution - threshold resolution based on topography available from aerial surveys is recommended in computational modelling of the flow over Perdigao.

Abstract

Abstract
O sistema de distribuição de energia elétrica é a parcela do sistema de potência mais vulnerável aos eventos de interrupção, originados por fatores naturais externos ou intrínsecos aos equipamentos elétricos. Na mitigação dos impactos desses eventos, simuladores digitais em tempo real são utilizados na obtenção dos transitórios do sistema elétrico, todavia, essa técnica demanda grande esforço computacional. Nesse contexto, propõe-se uma técnica híbrida para simulação do transitório em sistemas de distribuição, combinando a alta taxa de amostragem dos modelos no domínio do tempo para monitoramento de tensão e corrente com a velocidade de processamento dos algoritmos que operam os modelos fasoriais em regime quase-estacionário, ou permanente. A metodologia proposta também permite considerar diferentes tecnologias de geradores distribuídos acoplados na rede. Os resultados dos testes realizados indicam a consistência da metodologia proposta, representando o comportamento do transitório no sistema de distribuição de energia elétrica. Todas as simulações realizadas são comparadas com valores amostrais obtidos usando um software comercial especializado.