Teachers training for digital inclusion from school 2.0 plan: case study

The development of information and communication technologies has supposed a revolution into the society which has gone on marking the progression of the educational life of individuals. Therefore, different public governments have been designing for more than two decades programs and strategies including them to the teaching and learning processes. This circumstance has put in evidence the need of providing the teachers with all educative levels of a training which qualifies them for the inclusion of technologies in their class methodology. In this paper we present the results of a research carried out with teachers related to specific classes in private schools from Córdoba (Spain), due to the fact that one of the greatest problems that the technology development has produced is the so-called digital breach. By means of a transversal, no correlational descriptive study, we have formulated six questions through which we will determine the needs, complexities and views that the teachers of these classes have about their training. The most significant result indicates that even though they have received technology training, they think that this is not enough and that that training is not adapted to the type of students that they can find in their classes

Teachers training for digital inclusion from school 2.0 plan: case study

El desarrollo de las tecnologías de la información y la comunicación han supuesto dentro de la sociedad una revolución que ha ido marcando el devenir de la vida educativa de los individuos. Así, desde diferentes organismos públicos se han ido desde hace más de dos décadas, diseñando programas y estrategias que incorporen estas a los procesos de enseñanza y aprendizaje. Esta circunstancia ha puesto de manifiesto la necesidad de proporcionar a los docentes de todos los niveles educativos de una formación que les capacite para la inclusión de las tecnologías en su metodología de aula. En este artículo presentamos los resultados de una investigación realizada con docentes vinculados a las aulas específicas de los centros privados de la ciudad de Córdoba (España), dado que uno de los mayores problemas que ha generado el desarrollo tecnológico es la denominada brecha digital. A través de un estudio transversal, descriptivo no correlacional, se han planteado 6 interrogantes a través de los cuales determinaremos las necesidades, complejidades y visiones que sobre su formación tienen los docentes de estas aulas. El resultado más significativo indica que si bien han recibido formación tecnológica, consideran que no es suficiente ni se encuentra adaptada para la tipología de alumnado que tienen en sus clases.The development of information and communication technologies has supposed a revolution into the society which has gone on marking the progression of the educational life of individuals. Therefore, different public governments have been designing for more than two decades programs and strategies including them to the teaching and learning processes. This circumstance has put in evidence the need of providing the teachers with all educative levels of a training which qualifies them for the inclusion of technologies in their class methodology. In this paper we present the results of a research carried out with teachers related to specific classes in private schools from Córdoba (Spain), due to the fact that one of the greatest problems that the technology development has produced is the so-called digital breach. By means of a transversal, no correlational descriptive study, we have formulated six questions through which we will determine the needs, complexities and views that the teachers of these classes have about their training. The most significant result indicates that even though they have received technology training, they think that this is not enough and that that training is not adapted to the type of students that they can find in their classes.peerReviewe

Control strategies for improving power quality and PLL stability evaluation in microgrids

In recent years the interest in environmental protection and energy sustainability has steadily increased; this fact has promoted research activities, and projects focused on non-conventional renewable energy (NCRE) sources as a replacement for fossil fuels. In this context, NCRE-based technologies offer a solution for integrating distributed energy resources where the Microgrid (MG) concept has been introduced to facilitate the integration of a large number of micro-generators, energy storage units and loads. This integration is enabled by power electronic converters, and therefore there is an increase in the number of these devices in the modern electrical power systems. The proliferation of power electronic-based systems will inevitably affect both the power quality and the stability of electrical systems which have power electronic interfaces. In this context, two key issues that need to be addressed are the following: (i) the imbalances and harmonics inherently present in MG due to the random nature of loads and (ii) since MGs are weak systems, the stability between the power electronic-interface and the Point of Common Coupling (PCC). These two critical issues in MGs are studied in this thesis. The former is analysed considering 4-leg systems while the latter is studied considering a 3-leg system. The 3-wire system is used for developing a methodology to study the effects of the weak nature of MGs on a simple system. As future work, this methodology can be modified to analyse specific control schemes proposed in this thesis to manage imbalances and harmonic in MGs. To manage imbalance and harmonic issues in 4-leg MGs, two approaches are proposed. First, a novel methodology based on the application of a 4-leg shunt Active Power Filter (APF) is proposed. The control for the compensator is based on the Conservative Power Theory (CPT) augmented by resonant controllers. Experimental validation of the APF will be performed with a focus on the transient behaviour and on its performance when frequency variations occur. In the second approach, a cooperative control scheme based on the CPT is proposed for sharing imbalances and harmonics in three-phase four-wire droop-controlled systems. With this approach, it is demonstrated that the CPT can be an effective tool to develop imbalance sharing algorithms in isolated MGs.The behaviour of proposed control schemes is demonstrated using experimental prototypes deployed in a laboratory scale 4-leg MG, and using unbalanced and distorted conditions of a real isolated MG located in Canada. To study how the weak nature of MGs affect the stability of the interface between a converter and the PCC, a stability analysis focused on the phase-locked loop (PLL) has been undertaken based on a simple dq model proposed in this thesis. The aim of this proposal is to understand the effect of the weak nature of the MG (measured with the short circuit ratio) and the PLL bandwidth on the stability of the system. The system studied corresponds to a 3-leg converter connected to a balanced three-phase weak grid. The performance of this method is validated through simulation using Plexim PLECS software, and experimental validation using a laboratory-scale system is performed. The main contributions of this thesis can be summarised as follows: • In microgrids, relatively large variations in the electrical frequency may occur. The sensitivity to grid frequency variations is a known limitation of the CPT, and this work proposes and validates an implementation approach that shows the limited impact of frequency variation on the APF performance. • The CPT is applied to 4-wire systems considering full control of the 4 legs in the APF, to regulate the positive, negative and zero sequence voltages synthesised by the power converter. This includes the operation of the CPT compensator with single-phase non-linear loads. • The proposed sharing algorithm uses a novel approach based on the CPT methodology that can be used to implement a simple identification of the balanced, unbalanced and non-linear components of the currents and powers. Separation of the sequence components is not required. This produces a more robust imbalance sharing algorithm, particularly because most of the sequence separation algorithms are strongly affected by noise, harmonic distortion, small variations in the sampling time, etc. • A very simple method to share harmonic distortion between the generation sources is realised considering the application of the CPT transform. In this thesis, this methodology is discussed and experimentally validated. • A control algorithm is proposed based on the CPT which is very robust to issues such as distortion, noise, changes in the sampling time etc. As is demonstrated in this work, it is very simple to extend the proposed methodology to include harmonic distortion. • A systematic PLL design process is proposed to be used in weak grids to ensure system stability. This design process is based on a proposed low-complexity small signal model of the system in the dq reference frame. Based on this proposal, it could be possible (in future work), analyse the effects of the weak nature of MGs on the performance of the CPT-based controllers proposed in this thesis

Experimental evaluation of a CPT-based 4-leg active power compensator For distributed generation

Four-wire microgrids (MGs) and distribution systems are inherently unbalanced with the presence of negative and zero sequence components in voltages and currents. In small autonomous systems, the imbalance, in addition to the harmonic distortion produced by nonlinear loads, can significantly affect the power quality, loadability, and stability of the system. Furthermore, in isolated networks with significant generation from intermittent renewable energy sources, the stiffness of the system is reduced and this could amplify the effects of imbalance on the stability and power quality. To mitigate some of these problems, a novel methodology based on the application of a four-leg active power filter is proposed in this paper. The control of the compensator is based on the conservative power theory augmented by resonant controllers. The behavior of the proposed system is demonstrated using an experimental prototype deployed in a laboratory scale MG

Single-phase consensus-based control for regulating voltage and sharing unbalanced currents in 3-wire isolated AC microgrids

A distributed control strategy is proposed to share unbalanced currents in three-phase threewire isolated AC Microgrids (MGs). It is based on a novel approach where, rather than analysing the MG as a three-phase system, it is analysed as three single-phase subsystems. The proposal uses a modified single-phase Q - E droop scheme where two additional secondary control actions are introduced per phase. The first control action performs voltage regulation, while the second one achieves the sharing of negative sequence current components between the 3-legs power converters located in the MG. These secondary control actions are calculated online using a consensus-based distributed control scheme to share negative sequence current components, voltage regulation, and regulating the imbalance at the converters' output voltage to meet the IEEE power quality standards. The proposed methodology has the following advantages over other distributed control solutions, such as those based on the symmetrical components or those based on the Conservative Power Theory: (i) it achieves sharing of unbalanced currents, inducing smaller imbalances in the converters' output voltages than those of other methods, and (ii) the sharing of the unbalanced currents is simultaneously realised in both the sequence domain and the a-b-c domain. The latter is difficult to achieve using other solutions, as will be demonstrated in this work. Extensive experimental validation of the proposed distributed approach is provided using a laboratory-scale 3-wire MG

Distributed Control Strategies for Microgrids: An Overview

There is an increasing interest and research effort focused on the analysis, design and implementation of distributed control systems for AC, DC and hybrid AC/DC microgrids. It is claimed that distributed controllers have several advantages over centralised control schemes, e.g., improved reliability, flexibility, controllability, black start operation, robustness to failure in the communication links, etc. In this work, an overview of the state-of-the-art of distributed cooperative control systems for isolated microgrids is presented. Protocols for cooperative control such as linear consensus, heterogeneous consensus and finite-time consensus are discussed and reviewed in this paper. Distributed cooperative algorithms for primary and secondary control systems, including (among others issues) virtual impedance, synthetic inertia, droop-free control, stability analysis, imbalance sharing, total harmonic distortion regulation, are also reviewed and discussed in this survey. Tertiary control systems, e.g., for economic dispatch of electric energy, based on cooperative control approaches, are also addressed in this work. This review also highlights existing issues, research challenges and future trends in distributed cooperative control of microgrids and their future applications

Formación de docentes para la inclusión digital desde el plan escuela 2.0: estudio de un caso

URL del artículo en la web de la Revista: https://www.upo.es/revistas/index.php/IJERI/article/view/2851The development of information and communication technologies has supposed a revolution into the society which has gone on marking the progression of the educational life of individuals. Therefore, different public governments have been designing for more than two decades programs and strategies including them to the teaching and learning processes. This circumstance has put in evidence the need of providing the teachers with all educative levels of a training which qualifies them for the inclusion of technologies in their class methodology. In this paper we present the results of a research carried out with teachers related to specific classes in private schools from Córdoba (Spain), due to the fact that one of the greatest problems that the technology development has produced is the so-called digital breach. By means of a transversal, no correlational descriptive study, we have formulated six questions through which we will determine the needs, complexities and views that the teachers of these classes have about their training. The most significant result indicates that even though they have received technology training, they think that this is not enough and that that training is not adapted to the type of students that they can find in their classes.El desarrollo de las tecnologías de la información y la comunicación han supuesto dentro de la sociedad una revolución que ha ido marcando el devenir de la vida educativa de los individuos. Así, desde diferentes organismos públicos se han ido desde hace más de dos décadas, diseñando programas y estrategias que incorporen estas a los procesos de enseñanza y aprendizaje. Esta circunstancia ha puesto de manifiesto la necesidad de proporcionar a los docentes de todos los niveles educativos de una formación que les capacite para la inclusión de las tecnologías en su metodología de aula. En este artículo presentamos los resultados de una investigación realizada con docentes vinculados a las aulas específicas de los centros privados de la ciudad de Córdoba (España), dado que uno de los mayores problemas que ha generado el desarrollo tecnológico es la denominada brecha digital. A través de un estudio transversal, descriptivo no correlacional, se han planteado 6 interrogantes a través de los cuales determinaremos las necesidades, complejidades y visiones que sobre su formación tienen los docentes de estas aulas. El resultado más significativo indica que si bien han recibido formación tecnológica, consideran que no es suficiente ni se encuentra adaptada para la tipología de alumnado que tienen en sus clases.Universidad Pablo de Olavid

A Control Algorithm Based on the Conservative Power Theory for Cooperative Sharing of Imbalances in 4-Wire Systems

© 1986-2012 IEEE. A cooperative control scheme based on the conservative power theory (CPT) is proposed, which can share imbalances in three-phase four-wire droop-controlled systems. By utilizing the CPT, the balanced, unbalanced, and distorted components of the currents and powers in a microgrid can be identified. Using control loops based on virtual impedances and implemented in the stationary a-b-c frame, the imbalances and harmonics are shared between the different four-leg inverters in the microgrid. A secondary control loop is implemented to regulate the maximum voltage imbalance/distortion at the point of common coupling or any other point in the microgrid. The theoretical background of the method is presented, and experimental validation is demonstrated using a laboratory-scale microgrid with two inverters operating at 5 kW

Enhanced two consecutive samples based de-modulation technique for atomic force microscopy application

This article investigates robust amplitude detectors suitable for atomic force microscopy (AFM) while discussing better alternatives. An AFM instrument’s measurement unit is responsible for providing the amplitude information obtained from the tip of a cantilever beam to identify the surface smoothness of a test material. Therefore, two efficient approaches are suggested to leverage Lyapunov’s theory while adhering to better noise suppression and DC-offset rejection capabilities. Nevertheless, an enhanced two samples-based Lyapunov’s demodulation approach is proposed to detect the amplitude information rapidly. Consequently, the modifications applied to the conventional method help reduce the tuning efforts and structural complications. The proposed solution remains structurally simpler and useful for high- and low-frequency probes. Furthermore, the extensive design guidelines for all techniques and the simulation results are presented. Different amplitude signals are synthetically generated from several rough pseudo-test surfaces for early verification and sent to a real-time digital controller to judge the proposal’s efficacy

Distributed Control Strategy Based on a Consensus Algorithm and on the Conservative Power Theory for Imbalance and Harmonic Sharing in 4-Wire Microgrids

A distributed control system is proposed which uses the Conservative Power Theory (CPT) and a consensus algorithm to share imbalance and harmonics between different converters in three-phase four-wire droop-controlled Microgrids (MGs). The CPT is used to identify the balanced, unbalanced and distorted components of the currents and powers in the system. Control loops based on virtual impedance and implemented in the stationary a-b-c frame are then used to distribute these components between the various converters in the MG. The magnitudes of the virtual impedances are adaptively calculated using a novel consensus-based distributed control scheme with the aim of sharing imbalances and harmonics according to the residual VA capacity of each converter whilst regulating the imbalance and distortion at their output to meet the appropriate IEEE power quality standards. Extensive simulations show that the proposed distributed control has excellent performance, and experimental validation is provided using a laboratory-scale 4-wire MG