Abstract
A fully operational Multi-Terminal DC (MTDC) grid will play a key role for the creation of AC systems interconnection and to integrate offshore wind farms. Disturbances (at both AC and DC side) may culminate in the sudden disconnection of onshore HVDC-VSC (High Voltage Direct Current - Voltage Source Converter). To continue operating the DC grid under these conditions, the development of control functionalities is required. A communication-free advanced control scheme is proposed to be used as a supplementary local control acting at VSC level and aiming on providing fast active power accommodation in the DC grid, culminating on the mitigation of the resulting DC overvoltage. The implementation of the proposed control mechanisms exploits a set of coordinated local control rules at the converter stations and at wind turbines (WT) level. The performance of the proposed strategies is discussed and assessed through numerical simulation in the paper.

Abstract
Power systems with high wind penetration experience increased variability and uncertainty, such that determination of the required additional operating reserve is attracting a significant amount of attention and research. This paper presents methods used in recent wind integration analyses and operating practice, with key results that compare different methods or data. Wind integration analysis over the past several years has shown that wind variability need not be seen as a contingency event. The impact of wind will be seen in the reserves for non-event operation (normal operation dealing with deviations from schedules). Wind power will also result in some events of larger variability and large forecast errors that could be categorized as slow events. The level of operating reserve that is induced by wind is not constant during all hours of the year, so that dynamic allocation of reserves will reduce the amount of reserves needed in the system for most hours. The paper concludes with recent emerging trends.

Abstract
In this paper is presented a methodology to identify and evaluate the influence of the external elements on the Transmission System Operator's (TSO) responsibility area. The algorithm is based on the influence factor approach and is described for this purpose. This algorithm offer a concrete support in the determination of the observability area, which at the end remains in the responsibility of a single TSO. The influence factor is a numerical value used to quantify the greatest effect of the outage of an external network component on any internal network branch. The proposed methodology was applied to identify and to assess the influence of the external elements on the Portuguese transmission network. All simulations of the Portuguese and Spanish systems were performed using the computational software package PSS/E of Siemens/PTI. The results obtained with the proposed methodology are compared with the solutions produced by the horizontal network methodology.

Abstract
A new strategy was purposed and is being tested during this year, to increase students' participation and promote continuous learning and students' engagement in master's courses classes. With the implementation of the Bologna Process, the spectra of students has increased, which increases the difficulties faced by the lecturers since these students present different backgrounds and knowledge, thereby increasing the number of hours necessary to assure the completion of the programs. A description of a new approach design to increase students' participation, which is being tested in three different Universities and Polytechnic Institutes in Portugal is presented in this paper and some preliminary results are discussed.

Abstract
This paper presents a study were the Rough Set Theory and Data Mining Technique are applied to the electrical power system. The Data Mining technique classifies the system operation in four possible states: normal, alert, emergency (emergency I and emergency II). The states, that correspond to the normal state can be classified as secure and insecure the remaining ones. In this security studies, the overloads in transmition lines and the violation of the voltage limits are used to classify and rank these contingencies. This technique was applied to the 118IEEE busbar test power network and the results obtained are analyzed. Finally, some conclusions that provide a valuable contribution to the understanding of the power system security analysis are pointed out. © 2013, Springer Science+Business Media Dordrecht.

Abstract
The constant changes occurring in today's teaching and learning processes provide a continuous improvement in the interaction of information. At the same time, globalization and the need for streamlining time facilitate the development of new methods of imparting knowledge. With the new information technologies, new forms of learning occur adding greater dynamism to the information. This form of learning, which optimizes time and space, is known as distance learning and it is being amply used in many different areas. Distance education presents the advantage of facilitating the teaching and learning processes without face-to-face interaction as knowledge is transmitted, partly or as a whole using technology. In fact, technological innovation has assumed a vital role in education. Looking to achieve more efficiency in carrying out the various activities, the job market constantly requires an investment in new skills and knowledge so that the professionals can operate the equipment and working tools, successfully and with quality. This paper presents a new system of learning a curricular unit of Circuit Theory using desktop virtual reality (VR). The software provides the possibility to understand the relationship between the physical concepts of an electrical circuit, direct or alternating current, through computer simulations and animations. This work was developed to demonstrate how a desktop VR prototype, "Virtual Electric Manual"-VEMA, can be applied to an engineering unit and used to enhance security and resourcefulness in using electrical equipment. Several interactive scenes were developed to illustrate the idea using a measurements and instrumentation laboratory as virtual environment. A range of interactive learning environments are presented: the menu with the first interactive experiment is the simulator of a DC circuit. It allows the student to analyze the setting up of a parallel, or series-parallel resistive circuit series powered by direct current; the second menu, features the simulator of an alternating current circuit and demonstrates how the student can perform the analysis of a circuit with resistors, inductors and capacitors; the third interactive experiment is the simulator of a three-phase alternating current circuit; the fourth menu refers to a study on the transitional phenomena. Finally, the fifth menu is an interactive experiment related to the phenomena of resonance. VEMA offers students the opportunity to understand the processes, helping them to better discern the procedures and trains them to interact with the equipment. The VEMA prototype addresses these issues and highlights the potential benefits of using VR for this purpose. Each experiment will provide technical and scientific knowledge in order to give the student/user adequate information and training in the subject.