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Researchers and education professionals agree that educational research is often disconnected from the problems and issues of everyday practice: a division that creates the need for new research approaches that speak directly to the problems of practice and that lead to the development of "usable knowledge". As a consequence of this disconnection between practice and research results, physics classes in Argentina rarely present opportunities for students to get productively engagement in the discipline. In this paper, some results of previous research have been selected for designing an introductory class to electrical circuits for high school. The methodology used is Design-Based Research. The designed class is implemented in 2 groups of 15 students aged 14. In class, the effectiveness of learning is analyzed from the considerations raised by Engle and Conant in 2002, to account for Productive Disciplinary Engagement (PDE). The results show that 1) students engage productively in a disciplinary manner when working with activities designed based on Engle and Conant's 2002 guidelines and, 2) the presence in the class of a student possessing the correct knowledge on the subject addressed, can interfere in the distribution of authority among the class participants and therefore in the degree of PDE reached by all students. [ABSTRACT FROM AUTHOR]

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In this paper, a computer vision inspection methodology is presented for the detection and segmentation of areas of wear by electric arc on the surface of electrical contacts using segmentation by instances. Cadmium is a toxic metal frequently used in the manufacture of alloys for electrical contact, so efforts have been made to replace or eliminate this element from the industry. Our work proposes an approach oriented to the automation of the inspection process, which reduces the subjectivity of the repetitive task of inspecting electrical contacts, allowing to compare two different alloys, such as one with Cadmium (Cd) and the other with Copper (Cu)., subjected to the same conditions and determine which of them presents less wear by electric arc. In this way you can know if the new part is better, equal or worse in terms of performance. Initially, an adaptation was made of the source code hosted in a github repository of mask R-CNN of the Matterport corporation, where variables, classes were modified, and directories were created according to our needs. The results obtained show that the masks generated by the algorithm adjust very well to contact wear, despite the irregular shape of the damage. However, the "charred" edge was probably not considered, because in training images it was a feature that few images presented, so segmentation may not be considering this factor. [ABSTRACT FROM AUTHOR]

Circuit breakers serve to connect and disconnect electric circuits under any operation conditions. Improving circuit breaker reliability is important for the correct operation of electric power systems. In this paper, we use one of the existing methods for the analysis of reliability in devices and components according to Norsok Standard Z-013. The criticality level of the circuit breakers in a substation is determined from the quantity of operational failures, the power flow through the circuit breaker, and the circuit breaker incidence in the electric power system stability. The paper includes the analysis of historical data over a five-year period and shows the results of the obtained mathematical expression. These results will allow developing maintenance strategies directed towards the most critical circuit breakers to improve their reliability. [ABSTRACT FROM AUTHOR]

Mathematical Model of a Series-Parallel (SP) photovoltaic (PV) generator represents each module through an equivalent electrical circuit denominated single diode model, this model has associated a nonlinear equation system that describes the electrical behavior of SP generator. This paper presents a solution of this system using optimization methods widely using: Trust Region Dogleg and Particle swarm optimization (PSO) for solving the electrical model of PV generator operating under homogeneous or non-homogeneous conditions, changing the number of submodules and shading pattern. It has been made simulations about generators composed by 3 and 15 series submodules, operating under different partial shading conditions. Between the implemented methods, Trust Region Dogleg show a better performance than other methods, with 2 and 14 times less computation time than the reference method and PSO, respectively, and a RMSE equal or 50% lower than PSO. [ABSTRACT FROM AUTHOR]

Copyright of Revista EIA is the property of Escuela de Ingenieria de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista EIA is the property of Escuela de Ingenieria de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a general method for simulating the flow behavior in the fin-and-tube heat exchangers with high flexibility in handling the information. This procedure is based on the use of Object-Oriented Programming and specifically using C+--H, this because of all the advantages of this type of programming. Data entry is carried out by files, so that third-party programs can generate configuration and permit calculation in parametric form. The results for the analysis are presented in three different formats: comma separated value (CSV), structured plain text and self-documenting (XML) and a graphical display of results (VTK). [ABSTRACT FROM AUTHOR]

In this paper are presented the results of the influence of phase dispositions of a double circuit's transmission lines in various important aspects like its equivalents inductive and capacitive parameters of sequence positive, negative and zero, its tension drops and active y reactive losses, its ecological impact, the corona losses value, its chargeability, etc. This result was obtained modeling the double circuit line at 220 kV that link the generation station East of Havana with the bus bar at 220 kV of Cotorro Sub Station. Beside of that, it was analyzed the error make when the mutual coupling between the line circuits is not take into account. [ABSTRACT FROM AUTHOR]

The presented paper shows a simple procedure for the estimation of the operation parameters of induction motors with arbitrary load. The proposed method combine the equivalent circuit estimation by manufacturer data, as well as voltage and current measurements obtained with hook-on instruments. Using Matlab 6.5 a practical implementation of this method was obtained and it has served to proof several practical cases. The presented procedure is more accurate than other methods offered by commercial software. [ABSTRACT FROM AUTHOR]

This paper proposes a methodology to build hybrid models to fault location in power distribution systems, this methodology will allow to the utilities improve their quality indexes corresponding energy service continuity (DES and FES indexes). The hybrid model in methodology is composed by a technique based on knowledge (LAMDA tecnique) and other based on model (Ratan Das algorithm). The LAMDA technique is a technique based on artificial intelligence inheriting characteristics of the fuzzy logic and neural networks. The Rantan Das algorithm, is fault location algorithm that estimate the fault location from voltage and current phasors in the moment of fault and moreover some electric parameters of the distribution system. The novel thing of the methodology is centred in which with the implementation of the hybrid model is improved the precision in the estimation of the fault location, due to that is reduced the multiple estimation of the fault location algorithm by the technique based on knowledge. Finally, are presented the results obtained in test realized with a distribution circuit of 24 kV and length 60 km, approximately. [ABSTRACT FROM AUTHOR]

One of the goals of parameter identification in asynchronous motors is efficiency evaluation in field conditions. According to the equivalent circuit method, knowing the parameters of the Park circuit in the operating range of the machine, adapted to the power quality of field conditions, corresponding calculation are made. In unbalanced voltage condition, there are some complexities because there are two sets of parameters belonging to the positive and negative sequence networks differing fundamentally in the rotor circuit. This paper, with the application of genetic algorithm; (GA) , a new approach is proposed to identified the parameters of both sequences combining the powerful proprieties of GA with one initial vector of parameters that allows reduce the search time without needs special proofs of some complexity that in field conditions are very expensive or impossible to do. [ABSTRACT FROM AUTHOR]

One of the goals of parameter identification in asynchronous motors is efficiency evaluation in field conditions. According to the equivalent circuit method, knowing the parameters of the park circuit in the operating range of the machine, adapted to the power quality of field conditions, corresponding calculation are made. In unbalanced voltage condition, there are some complexities because there are two sets of parameters belonging to the positive and negative sequence networks differing fundamentally in the rotor circuit. This paper, with the application of genetic algorithm (GA), a new approach is proposed to identified the parameters of both sequences combining the powerful proprieties of GA with one initial vector of parameters that allows reduce the search time without needs special proofs of some complexity that in field conditions are very expensive or impossible to do. [ABSTRACT FROM AUTHOR]

The article presents a paper which describes the elementary principle of operation of the main types of multilevel converters and its applications. It is said that classical frequency converter made up from a two level voltage or current source inverter has important drawbacks that injure the electrical system power quality and the behavior of the electrical apparatus fed by them. The study reveals that multilevel converter is the preferred choice for solving these problems.