Abstract
In a world with a global market that is continually increasing, the productivity management plays an important key role to keep the competitiveness. The productivity can be achieved through the availability that can be increased through the adoption of efficient maintenance practices, by focusing the organisations on adequate type of maintenance strategy. Condition Based Maintenance (CBM) uses primarily non destructive testing techniques, as environmental indicators, visual inspection, monitoring functioning variables and performance data. This kind of maintenance replaces tasks of scheduled maintenance by warranted interventions predicted by on-condition limits previously defined. The interventions occur only when the equipments presents abnormal symptoms. The intervals of CBM are determined based on the expected delay to fail and are managed through the frequency by which the predictive interventions have to be done. The technological advances are accepted and applied on CBM systems, which includes improved knowledge of failure mechanisms, advancements in, failure forecasting techniques, monitoring and sensor devices, diagnostic and prognostic software, communication protocols, and computer networking technologies. The measurement precision and sensitivity of the Condition Monitoring (CM) techniques are used because they affect the reaction time available to reduce or eliminate the consequences of the functional failure. CBM maintenance tasks must be applicable under the situation of cost effective improvement, including external costs. The base of development of this paper is supported by an integrated system called SMIT (Terology Integrated Modular System), that permits to manage the maintenance itself, including on-condition maintenance, but it is modular enough to permit to associate new features, namely this last approach, in order to maintain the system up-to-date and, always possible, to anticipate the future.

Abstract
The paper presents a study of the convergence characteristics and an assessment of the performance of the algorithm used to solve power system state estimation problem. The algorithm is studied to determine and compare the convergence patterns using several measurement sets consisting of line flows, bus injections, voltage magnitudes and line currents. The algorithm was tested on different IEEE test systems. Results related to the test with IEEE 14 bus bar system are presented.

Abstract
In a global world, the survival and sustainability of industrial companies depends on several factors: production continuity; quantity assurance; quality assurance; competitive prices for products; on time production; flexibility; operational safety and environmental safety. To achieve these goals, sustainable industrial operations must rely on dependable systems and equipments. Dependability is defined as "the collective term describing the availability performance of any simple to complex product" [1]. This definition can be extended for industrial operations, to their reliability and maintainability design characteristics. As there are no perfect systems and equipments designs, component degradation and failures will always occur during their life cycle. So to keep their dependability level during the life cycle good maintenance support is essential. In this paper we will discuss the importance of maintenance to achieve the required dependability and sustainability for industrial production processes and how that can be achieved.

Abstract
An engineering curriculum requires that its future professionals should be fully prepared to accomplish a variety of tasks involving not only theoretical concepts, but also skills acquired through effective practice. In the Instituto Superior de Engenharia de Coimbra (ISEC), Department of Electrical Engineering, preference was given to apply methods integrating technology in the learning and then evaluating the outcomes. Problem-based learning (PBL) was used as an instructional strategy of active learning, and adapted for use in the Lighting Design course. The students are presented with a virtual scenario, quite similar to the real world, where they are required to perform as they would in a real life situation. The emphasis is given to PBL so that they can learn to become autonomous, skilled and explore their own potential as well as improve team work skills/spirit and that can be applied to a wide range of students and subject matters. PBL is introduced to the students as a 'learn by doing' project. The project incorporates aspects of electrical engineering and computing skills. This study analyses the learning process/techniques that help students deal with the complexity of a Lighting Design Project and assesses its effectiveness and impact on the students. Essentially, it encourages them to be in charge of their education. The benefits of PBL in the Lighting Design course are visible in the improvement of the study and analysis of a Lighting Design project. The method may also bring benefits for Electrical Engineering programmes where educators struggle for improved teaching and learning. The simulation was performed using the Dialux 4.3 software package that runs in Windows Vista or XP environment.

Abstract
In this paper it is proposed an efficient contingency screening and ranking algorithm for assessment and classification of multiple contingencies of an Electric Power System using the Rough Set theory. The developed methodology produces a classification of the system operation in five possible states: normal, alert, emergency, in-extremis and restorative. These different operating states correspond to six levels of security: secure, alert, correctively secure, alert no correctable, emergency and restorative. The states can be classified horizontally as secure, that correspond to the normal state and insecure for the remaining ones. The developed computer programs, the SECURsySTEM were applied to the IEEE 118 busbars test power network and results are presented and analyzed.

Abstract
The electrical power production from dispersed energy sources or distributed generation is playing an increasing role in the supply of electricity in the liberalized electricity markets. Distributed generation can have a significant impact on the power flow, voltage profile, stability and the power quality for both customers and electricity suppliers. In this paper it is studied and analysed the influence of a wind farm in the dynamic voltage stability of a power network. A short-circuit in the middle of the transmission line and a significant load demand disturbance situation were simulated. The automatic voltage regulators of the generating units, the turbine speed governors and the double fed induction generator models were taken into account. The simulation results were obtained using the EUROSTAG software package. Finally, some conclusions that provide a better understanding of the dynamic voltage stability are pointed out.