C. Machado Ferreira

Distance education using a desktop virtual reality (VR) system

The constant changes occurring in todays 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.

Probabilistic Steady-State Security Assessment of an Electric Power System Using A Monte Carlo Approach

In this paper it is proposed a probabilistic stead-state security assessment of an electric power system using a Monte Carlo method. This approach evaluates a probabilistic measure of the system security, instead of just a particular response to a specified contingency. Performance indices are used to assess the impact of the contingencies in the power system security. These indices allow to accurately evaluate the influence of the overloads, voltage limit violations and voltage stability problems in the power network. A probabilistic version the SECURsySTEM software package developed by the authors was applied to the IEEE 118 busbars test power system. During the simulation time, the occurrence of contingencies and the subsequent protective actions are assumed as a stochastic process. Finally, some conclusions that provide a valuable contribution to the understanding of the power system security analysis are pointed out.

Electrical engineering teaching and distance learning using a desktop virtual reality system

Higher education has evolved in the last decade with the use of information technology. This change was called distance education, a teaching method in which the student does not need to meet with the teacher on a certain day and time. The student may be either at home or at work and may have no interaction with the other parts, either the teacher or other students. It has allowed the institutions to resolve geographical gaps in order to reach the largest number of students. On the other hand, it paved the way for the “non-traditional” universities oriented for “adult work”, in a narrow range of graduation programs, compatible with the current demands from industry. It is also important to mention that distance education is becoming increasingly appropriate for non-academic studies, such as corporate training environments. This paper addresses Circuit Theory systems, more specifically laboratory practices geared towards teaching and learning. The choice was made from observing the needs in the specific context of a measures and instrumentation laboratory, mainly related with access to the means and equipment to carry out laboratory practice. The purpose of the work is the use of virtual experimentation to carry out laboratory practice and also as an alternative tool to meet the needs of access to the means and equipment of the laboratory. In the present case, the basis of the project was the construction of a 3D lab environment (Measures and Instrumentation) where the equipment and the components can be seen and manipulated. The project involves simple electrical schematics, which later can be changed in values, presenting new results, and displays a set of menus and submenus to support experiments. The virtual laboratory can accommodate new devices and scenarios, being adapted to new subjects, such as electric machines and power system analysis of the Electrical Engineering program. 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. The added value of these various features in the educational context is that they contribute to the construction of new virtual environments, able to benefit the communication between teachers and students and among themselves, thus creating new opportunities for each student to participate more actively in his/her own learning construction process. Rather than being seen as mere information files, these e-learning platforms should be perceived as a means to promote interaction and experimentation through technological resources.

Desktop VR systems - A distance learning method and technology

This paper discusses the effective contribution of a Learning Object (LO) to teach circuit theory based on research conducted with students of higher education, and their interaction with a teacher of Electronics. From the results of such research, it is pointed out which features one wants in the LO so that it successfully promotes learning. It is in this perspective that this work was conceived having as goal the development of LO, admitting that this may be a possible alternative to represent models of interactions, which occur within the area, thereby improving understanding of physical concepts, in particular those involved with the subject of electrical circuits. It has also as objective to characterize the learning process through a series of situations that are replicated leading to a set of behaviors from the students. It is assumed that the use of this tool can lead to acquiring a specific set of skills, a better practice and meaningful learning.

Reactive power management of a wind farm to prevent voltage collapse of an electric power system

Nowadays, the large penetration of wind power generation poses new challenges for dynamic voltage stability analysis of an electric power system. The practical importance of dynamic voltage stability analysis is to help in designing and selecting counter-measures in order to avoid voltage collapse and enhance system stability. The impact of wind integration on reactive reserve requirements is a current area of interest for renewable integration studies and power system operators. In this paper is studied a new wind power plant model with reactive power management. The active power and the frequency management are taken into account too. The developed model can be used to represent, in a simplified way, an entire wind farm in order to simulate the dynamic voltage stability of the system, whatever the technology involved in the wind turbine. The system is completely modelled by a single dynamic converter model with appropriate control loops intended to reproduce the overall response of a wind farm for different grid events, such as faults or voltage and reactive power management at the point of common coupling.

Collaborative projects involving industry and academia to enhance electrical engineering education: The perspective of three Portuguese Higher Education Institutions at the master degree level

In this paper, Electrical Engineering Education at the Master level is presented through three perspectives of collaborative projects involving industry and academia. The presented perspectives originate from three Portuguese Higher Education Institutions representing the University, Military Academy and Polytechnic School viewpoints. Throughout the presented projects, an increasing student motivation was observed, driven by the practical experience provided through the industrial sector approach. This cooperation also generates opportunities to develop new perspectives and ideas for follow-on projects as well as innovative academic publications.

Analysis of an Incomplete Information System Using the Rough Set Theory

In this paper it is applied a Rough Set approach that takes into account an incomplete information system to study the steady-state security of an electric power system. The Rough Set Theory has been conceived as a tool to conceptualize, organize and analyze various types of data, in particular, to deal with inexact, uncertain or vague knowledge. The knowledge acquisition process is a complex task, since the experts have difficulty to explain how to solve a specified problem. So, an incomplete set of relevant information may arise. The study presents a systematic approach to transform examples in a reduced set of rules. These rules can be used successfully to avoid security problems and provides a deeper insight into the influence of parameters on the steady-state system performance.

Identification and influence of the external elements on the transmission system operator's responsibility area

In this paper is presented a methodology to identify and evaluate the influence of the external elements on the Transmission System Operators (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.

Impact of external elements on the responsibility area of a Transmission System Operator using the influence factor method

In the last years, the electric power systems have been restructured, moving from a vertical integrated model to a market oriented environment. The new paradigms associated with the restructuring of the electricity sector made it critical to develop new efficient and reliable methodologies to study and analyze the security of the power networks. In this paper it is proposed a method to evaluate the impact of external elements on the responsibility area of a Transmission System Operator (TSO) using the influence factor method. This approach offers a concrete support in the determination of the observability area, which at the end remains in the responsibility of the 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 developed methodology was applied to study the IEEE 118 bus test power network. All simulations of the transmission systems of the IEEE 118 bus were performed using the PSS®E software package from Siemens PTI, making the division of the network in two countries (areas). From the simulation results, some conclusions that provide a valuable contribution to understanding the influence factor method are pointed out.

The Rough Set Theory applied to a set of the new severity indices

In this paper it is presented a study were the Rough Set Theory is applied to evaluated a set of the new severity index. The developed methodology produces a classification of the system operation in four possible states: normal, alert, emergency (emergency I and emergency II). The states can be classified as secure, that correspond to the normal state and insecure for the remaining ones. Severity indices are used to represent the impact of the reliable contingencies in electric power system Security studies. In this study the severity index are used to classify and ranked the contingencies. This methodology 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.