Abstract

Abstract
Power system restoration (PSR) is a very important procedure to ensure the consumer supply. In this paper, a decentralized multi-agent system (MAS) for dealing with the microgrid restoration procedure is proposed. In this method, each agent is associated with a consumer or microsource (MS) and these communicate with each other to reach a common decision. The agents solve a 0/1 knapsack problem to determine the best load connection sequence during the microgrid restoration procedure and then the proposed MAS is tested in one specific scenario where the microgrid is subjected to a blackout that occurred. This means that all the resources and loads are disconnected. This work is developed in Matlab/Simulink environment and the results show its feasibility and effectiveness in the microgrid restoration procedure.

Abstract
Climate change has been a much-commented subject in the last years. The energy sector is a major responsible for this event and one of the most affected by it. Increasing the participation of renewable is a way to mitigate these effects. However, a system with large share of renewables (like Brazil) is more vulnerable to climate phenomena. This article analyzes the implementation of smart grids as a strategy to mitigate and adapt the electricity sector to climate change. Different climate and energy sector scenarios were simulated using a bottom-up approach with an accounting model. The results show that smart grids can help save energy, increase network resilience to natural hazards and reduce operational, maintenance costs and investments in new utilities. It would also allow tariffs diminution because of generation and losses costs reductions.

Abstract
In this paper it is presented the study of the effect of Thyristor Controlled Series Compensation (TCSC) and Static Var Compensators (SVC) devices on voltage collapse phenomenon in power systems to increase system loadability. Comparative studies of TCSC and SVC performance on Dynamic Voltage Stability of an Electric Power System are presented. The models of TCSC and SVC were developed in EUROSTAG. The Automatic Voltage Regulators (AVR) of the generating units and the turbine speed governors were modelled in detail. Different load models were used and the Under Load Tap Changers (ULTC) were also taken into account. Finally, some conclusions that provide a better understanding of the dynamic voltage stability using Flexible AC transmission System (FACTS) devices during a disturbance are pointed out.

Abstract

Abstract
Metaheuristics (MH) aptitude to move past local optimums makes them an attractive technique to approach complex computational problems, such as the Travelling Salesman Problem (TSP), but there is lack of information on the parameterization procedure and the appropriate parameters to improve MHs' performance. In this paper the parameterization procedure of Simulated Annealing (SA) and Discrete Artificial Bee Colony (DABC) is addressed, with a focus on the Neighborhood Structure (NS). Numerous NS have been proposed for specific problems, which seem to indicate that the NS is a special parameter, whose optimization is independent of other parameters. The performance of eight NS was examined with SA and DABC under two optimization constraints, regarding computational time variation, to determine if there is one appropriate NS for the TSP problem, independent of the rest of the parameters of the optimization procedure. The computational study carried out for comparing the evaluation of the NS, including a statistical analysis, demonstrated a nonproportional increase in the performance of DABC with some NS. For SA the improvement of the solutions appeared to be more uniform with an almost nonexistent variance in improvement.