Abstract
This work proposes an innovative method based on autoencoders to perform state estimation in distribution grids, which has as main advantage the fact of being independent of the network parameters and topology. The method was tested in a real low voltage grid (incorporating smart grid features), under different scenarios of smart meter deployment. Simulations were performed in order to understand the necessary requirements for an accurate distribution grid state estimator and to evaluate the performance of a state estimator based on autoencoders.

Abstract
In the European Union (EU), the greenhouse emissions from the transportation sector increased around 36% since 1990, which degraded the environmental quality. This sector, owing to its oil dependency, is responsible for around a quarter of EU greenhouse emissions, and the road transportation represents about 20% of the total CO[[inf]]2[[/inf]] emissions in EU. Moreover, concerns such as the dependency on oil supply and the foreseen prices increase during this century have motivated a wide range of policy and technological measures for the transportation sector. A large part of these measures were to incentivize the electric vehicle (EV) adoption, which is one element with great potential to decarbonize the transportation sector and decrease its oil dependency. This chapter describes relevant methodologies to actively manage EV charging/discharging (as distributed storage devices) to achieve different goals, such as avoid grid congestion, the EV participation in primary frequency control, and the coordination of EV charging with renewable generation. To contextualize the methodologies described, a brief state of the art in active management functionalities for EV is provided. Some of the results obtained with the described approaches are also presented to demonstrate their overall performance. © 2016 John Wiley & Sons, Ltd. All rights reserved.

Abstract
This study presents a methodology for siting and sizing static synchronous compensator (STATCOM) devices in the Portuguese transmission system in order to improve system security following severe grid faults. Security issues arise since the Portuguese transmission system incorporates significant levels of wind generation without fault ride through and reactive current injection capabilities during grid faults. As the transmission system operator (TSO) is responsible for assuring system security, the goal of the study is to take advantage of the proved STATCOM ability for injecting reactive current in order to mitigate the disconnection of large amounts of wind farms in case of severe grid faults. The proposed methodology was developed and tested in coordination with the Portuguese TSO and it is based on the formulation of an optimisation problem in order to minimise the installed STATCOM power while ensuring its compliance with the current grid code requirements, namely in what concerns to the system stability and security. Given the discrete and complex nature of the problem, a hybrid approach, combining both a heuristic method and an evolutionary particle swarm optimisation (EPSO) algorithm was developed. Results show the effectiveness of the proposed methodology as well as its robustness regarding the validity of the obtained solutions while facing the most severe operational scenarios.

Abstract
Frequency stability in inverter-based renewable energy sources (RES)-dominated, low-inertia, power systems is a timely challenge. This paper employs a systematic approach, utilizing an artificial neural network (ANN) and dynamic simulation, to infer two key frequency stability indicators: nadir and rate of change of frequency (RoCoF). By reformulating the ANN mathematical model, these indicators are then integrated as mixed-integer non-linear constraints into a classical AC security-constrained optimal power flow (AC SCOPF), resulting in the proposed AC-F-SCOPF problem. The results of the proposed AC-F-SCOPF on the IEEE 39-bus system show that the problem identifies accurately the synchronous condensers which must run to ensure the frequency stability.

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
The expected growth of Distributed Generation (DG) penetration in distribution systems will fundamentally alter both planning and operating procedures of Distribution Network Operators (DNO). This means that distribution networks can no longer be considered as a passive appendage to the transmission network and should be explored actively to take full advantage of the capabilities of DG units available and avoid technical problems (such as line overloading or poor voltage profiles) resulting from massive integration of this type of sources. Presently, when the capacity of the generation, transmission and distribution systems is exceeded, the traditional utility response is expanding or reinforcing existing circuits through large investments in power transformers, substations or distribution feeders. However, in some situations such as in congested metropolitan areas these actions can have prohibitive costs or simply be impossible due to space restrictions, for instance. Although current investment costs of many solutions for energy storage remain extremely high, recent developments and advances in both energy storage technologies and power electronic interfaces are opening new doors to the inclusion of Energy Storage Systems (ESS) as a potentially viable solution for modern power applications, including their use in distribution network planning and operation. This paper presents a heuristic approach for siting and sizing of ESS in distribution networks in order to maximize the capacity of DG that can be integrated in the grid without bringing technical problems to network operation. The proposed methodology enables a technical and economical comparison between a strategy based on ESS deployment and exploitation and typical traditional DNO grid reinforcement strategies. Several technologies for ESS were considered, each one with different costs and technical characteristics. The proposed methodology was validated using a real Portuguese Medium Voltage (MV) distribution network.