Search

This study introduces a novel method for controlling an autonomous photovoltaic pumping system by integrating a Maximum Power Point Tracking (MPPT) control scheme with variable structure Sliding Mode Control (SMC) alongside Perturb and Observe (P&O) algorithms. The stability of the proposed SMC method is rigorously analyzed using Lyapunov's theory. Through simulation-based comparisons, the efficacy of the SMC controller is demonstrated against traditional P&O methods. Additionally, the SMC-based system is experimentally implemented in real time using dSPACE DSP1104, showcasing its robustness in the presence of internal and external disturbances. Robustness tests reveal that the SMC controller effectively tracks Maximum Power Points (MMPs) despite significant variations in load and solar irradiation, maintaining optimal performance even under challenging conditions. The results indicate that the SMC system can achieve up to a 70% increase in water flow rates compared with systems without MPPT controllers. Furthermore, SMC demonstrated high sensitivity to sudden changes in environmental conditions, ensuring efficient power extraction from the photovoltaic panels. This study highlights the advantages of integrating SMC into Photovoltaic Water Pumping Systems (PV-WPSs), providing enhanced control capabilities and optimizing system performance. The findings contribute to the development of sustainable water supply solutions, particularly in remote areas with limited access to the electrical grid. [ABSTRACT FROM AUTHOR]

Purpose: This work aims to establish a template containing a skeletal version of the existing Repository of Didactic Processes Data (RDPD) along with its environment and, by utilizing this system, to develop universal installation scripts enabling the implementation of the repository at any university in Poland. These scripts are used for cloning, meaning the template replication. They are intended to enable the implementation of Repository as a Service (RaaS) launched on demand by the service recipient. Design/methodology/approach: The RDPD skeletal version is developed as a system offering repository functionality for managing data from didactic processes. It does not contain visual identification elements and data. To operate, the skeletal version needs an environment that requires creating a VM on Proxmox and installing the OS and applications needed for RDPD: PostgreSQL, Apache, Tomcat, Solr, and Angular. The RDPD skeletal version and its environment create a template which is cloned by Ansible scripts running sequentially. Ansible scripts also configure the created clone. The university then only needs to customize the system and feed the repository with data. Findings: The university (client) provides identification parameters to generate a virtual machine (VM), ultimately containing the repository. In response, the RDPD system is automatically replicated and configured on a clone of the template in line with the parameters provided. Practical implications: A solution was proposed allowing for the automatic implementation of the RDPD repository at any Polish university. Hence, the provision of a service to generate a ready-to-use version of the RDPD system is significantly convenient for universities. Originality/value: The developed RDPD system, dedicated strictly to storing and managing data generated by a university, can be automatically implemented and configured per request. There are no such solutions, which is the original element of this work. [ABSTRACT FROM AUTHOR]

This paper describes the needs and development process of a CRIS for NIS, the Oil Industry of Serbia (NIS j.s.c.). NIS stands as a prominent energy conglomerate in Southeast Europe, specializing in oil and natural gas refining, research, production, and distribution. The Thinker platform, a derivative of DSpace-CRIS, underpins NTC's knowledge management. It boasts a robust architecture, bilingual interface, and advanced search capabilities powered by Apache Solr. The platform houses a diverse array of content, from articles and theses to standards and trainings, all meticulously cataloged by repository professionals. Emphasizing security, access is restricted within NIS's local network, ensuring monitoring and authentication through Microsoft Active Directory. Currently, efforts are underway to enhance user-centric reporting. With content spanning Serbian, English, and Russian languages, Thinker exemplifies NTC's commitment to cutting-edge knowledge dissemination and collaboration. [ABSTRACT FROM AUTHOR]

This paper presents the prototyping of a fuzzy logic-sliding mode control technique for improved dynamics of induction motors. The proposed technique used the new fuzzy logic-sliding mode control technique as the main drive control using indirect field-oriented control theory. A simulation model was designed and implemented in a MATLAB/Simulink environment. An experimental prototype of the proposed circuit topology was fabricated, with a 0.37 kW induction motor fed from a quasi-impedance source inverter (q-ZSI) controlled by fuzzy logic-sliding mode-based indirect field-oriented control. In the real-time control, a DSpace 1202 Microlab box was used as a deployment module for the new control scheme on the q-ZSI-fed induction motor. The performance was studied under various constant speed ranges and step/ramp speed responses, both in simulations and experimentally. In this study, the proposed control method showed improved dynamic behavior of the system under constant speed and forward speed operation. The impact of FL-SMC in speed tracking with fast speed convergence was validated with experimental results. Moreover, ripple-free voltage and the current of the induction motor were observed with the proposed control scheme. [ABSTRACT FROM AUTHOR]

Copyright of Electric Drive for Locomotives is the property of Electric Drive for Locomotives Editorial Office 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 the prototyping of a fuzzy logic-sliding mode control technique for improved dynamics of induction motors. The proposed technique used the new fuzzy logic-sliding mode control technique as the main drive control using indirect field-oriented control theory. A simulation model was designed and implemented in a MATLAB/Simulink environment. An experimental prototype of the proposed circuit topology was fabricated, with a 0.37 kW induction motor fed from a quasi-impedance source inverter (q-ZSI) controlled by fuzzy logic-sliding mode-based indirect field-oriented control. In the real-time control, a DSpace 1202 Microlab box was used as a deployment module for the new control scheme on the q-ZSI-fed induction motor. The performance was studied under various constant speed ranges and step/ramp speed responses, both in simulations and experimentally. In this study, the proposed control method showed improved dynamic behavior of the system under constant speed and forward speed operation. The impact of FL-SMC in speed tracking with fast speed convergence was validated with experimental results. Moreover, ripple-free voltage and the current of the induction motor were observed with the proposed control scheme.

The process of designing and controlling modular multilevel converter (MMC) poses numerous challenges. So, hardware-in-the-loop (HIL) simulation and transient analysis are necessary to test the efficacy and reliability of MMC in different operational conditions. This paper presents transient analysis of MMC using MATLAB/Simulink, and results are verified using HIL simulation to validate the performance of decoupled current and circulating current controllers in real-time (RT). The decoupled current control enables the independent control of real and reactive power in AC system, and circulating current control minimizes the circulating currents in MMC phase-legs. The transient analysis is performed on the study system with a rating of 1000 MVA, 220 kV in MATLAB/Simulink. The analysis is carried out for a step perturbation of 100 MW in the real power and 2.0 kA in reactive current references, and results show the satisfactory responses with MMC controllers. The simulation results are validated with HIL simulation of MMC using two RT simulators. The HIL simulation results show the satisfactory responses with closely matching responses to MATLAB/Simulink results. [ABSTRACT FROM AUTHOR]

In this paper, an adaptive Takagi Sugeno (TS) Fuzzy integrated Mixed Order Normalized Least Mean Square/Fourth Algorithm (MONLMS/F) is proposed for the unresolved voltage power quality issues in distribution system. The proposed control utilizes the cost function of mixed order of errors, which are based on second and fourth order and the feature of cost function overcomes the demerit of traditional basic least mean square method, which is based on second-order error. The implemented control technique has two main objectives. Firstly, the fundamental estimation of correct active and reactive signals from polluted grid voltage for computing the reference load voltages and second is the DC link voltage regulation. A correct weight estimation is achieved by Mixed Order Normalized Least Mean Square/Fourth Algorithm (MONLMS/F) and voltage regulation is performed by Takagi Sugeno Fuzzy (TSF) approach. The proposed integrated control enhances the capability of system against voltage deviation from the reference voltage and successfully eliminates the harmonics from polluted grid voltages. A bio-inspired optimizer like Spotted Hyena (SH) is integrated with TSF for self-tuning of the membership functions (MFs) and fuzzy rule to adapt the system variations and regulate fluctuations in the DC link for dynamic conditions. However, auto-tunned TS-Fuzzy have a fast transient response of DC and AC link voltage based on dynamic indicators like settling time (ts=0.12 s), undershoot (Us=3.4 %) and peak overshoot (Mp=5.6 %) are compared to classical PI controller. Nonetheless, the proposed TS-MONLMS/F control strategy outperforms the other classical control with low oscillations at any power quality scenario with improved dynamic response. The significant MATLAB simulation and experimental results are evaluated, and its performance is demonstrated with the dSPACE (DS1202) processor for experimental realization.

Energy-storage-equipped static synchronous compensators (E-STATCOM) are crucial devices in a modern power grid for regulating both the active and reactive power, thereby improving the efficiency and power quality. Current controllers commonly used with E-STATCOM devices include proportional-integral (PI), repetitive, and deadbeat controllers. However, each has application-dependent restrictions and therefore lack the ability to achieve optimal operation. This paper presents a novel hybrid current controller that combines the strengths of the PI, deadbeat, and repetitive controllers. The proposed current controller mitigates cross-coupling effects and provides a wide control bandwidth, thereby ensuring quick, precise, and robust response to system parameter variations. Moreover, the proposed controller provides an efficient disturbance rejection, presenting a holistic solution for enhanced performance of the E-STATCOM. The proposed controller not only overcomes the limitations of individual controllers, but also provides improved current regulation. A comparative analysis of the proposed hybrid controller and a conventional repetitive controller clearly shows the efficiency of the proposed technique. Experimental findings based on a three-phase E-STATCOM demonstrate that the proposed controller significantly minimizes cross-coupling effects and provides approximately $150~\%$ higher bandwidth compared to the conventional controller. In addition, applying the proposed controller shows $3~\%$ and $6~\%$ of total harmonic distortions (THD) during normal system operation and during periodic disturbances, respectively, which is approximately $38~\%$ lower than the THD observed with the conventional controller.

This manuscript describes a swift control prototyping (SCP) approach implemented within an industrial setting, utilizing a DC-DC nonlinear quadratic buck converter (QBC) to decrease production expenses of electronic materials and devices while improving power system efficiency. A practical experimental setup is utilized to develop a working prototype, transforming 380 VDC to 48 VDC with a power capacity of up to 500 W. The setup incorporates dSPACE CP1103 to execute Model in the Loop (MIL), Software in the Loop (SIL), and Hardware in the Loop (HIL) methodologies. Additionally, it employs advanced control strategies such as passivity-based control (PCB) and canonical forms, which are compared with classical Proportional-Integral-Derivative (PID) control arrangements to propose a comprehensive control scheme that ensures stability in the presence of real-time disturbances (RT). Finally, a performance analysis is conducted, assessing important indicators like reaction time, precision of signals, stability of the system, and efficiency in resource utilization. The document concludes by offering a performance evaluation that encompasses PI, Cp, CpK, Z-score, and ITAE. This assessment considers factors such as response time, signal accuracy, system stability, and the efficiency of resource utilization.

This document introduces a rapid control prototyping (RCP) approach applied to the industrial sector using a non-linear Quadratic Buck Converter (QBC) DC-DC. The goal is to reduce manufacturing costs for materials and electronic devices while enhancing the power quality in the system’s response. An experimental setup is utilized to create a functional model, converting 380 VDC to 48 VDC at a power level of 500 W. dSPACE CP1103 is employed to implement Model in the Loop (MIL), Software in the Loop (SIL), and Hardware in the Loop (HIL) simulations. Modern control techniques, including sliding mode control (SMC) and passivity-based control (PBC), are employed to devise a robust control scheme capable of maintaining stability in real-time (RT) and resisting disturbances. The document concludes with a performance analysis, PI, Cp, CpK, Z-score, and ITAE considering response time, signal accuracy, system stability, and resource utilization efficiency.

This study introduces a novel method for controlling an autonomous photovoltaic pumping system by integrating a Maximum Power Point Tracking (MPPT) control scheme with variable structure Sliding Mode Control (SMC) alongside Perturb and Observe (P&O) algorithms. The stability of the proposed SMC method is rigorously analyzed using Lyapunov’s theory. Through simulation-based comparisons, the efficacy of the SMC controller is demonstrated against traditional P&O methods. Additionally, the SMC-based system is experimentally implemented in real time using dSPACE DSP1104, showcasing its robustness in the presence of internal and external disturbances. Robustness tests reveal that the SMC controller effectively tracks Maximum Power Points (MMPs) despite significant variations in load and solar irradiation, maintaining optimal performance even under challenging conditions. The results indicate that the SMC system can achieve up to a 70% increase in water flow rates compared with systems without MPPT controllers. Furthermore, SMC demonstrated high sensitivity to sudden changes in environmental conditions, ensuring efficient power extraction from the photovoltaic panels. This study highlights the advantages of integrating SMC into Photovoltaic Water Pumping Systems (PV-WPSs), providing enhanced control capabilities and optimizing system performance. The findings contribute to the development of sustainable water supply solutions, particularly in remote areas with limited access to the electrical grid.

Purpose: Ghanaian public universities have fully embraced the concept of open access. This is evident in the increasing numbers of institutional repositories (IRs) by universities in Ghana. However, to ensure the sustainability of these IRs, it is vital the current IR infrastructure is capable of responding to current and future demands. The purpose of this study is to investigate the sustainability of the current IR infrastructure of public universities in Ghana. Design/methodology/approach: The convergent parallel mixed methods design was adopted. A total of 830 respondents comprising IR managers, library staff (digitisation and e-resources units), postgraduate students, lecturers and university librarians from five public universities in Ghana were sampled for this study. A questionnaire and a semi-structured interview guide were the main instruments used for data collection. Findings: The findings of this study revealed that the IR infrastructure of public universities in Ghana is robust and has the capacity to expand when the need arises. However, funding, cost of internet connectivity, personnel and erratic power supply were identified as major challenges confronting IRs in Ghana. Originality/value: This study highlighted Ghana's existing IR infrastructure situation. This study is a significant contribution to the literature from West Africa because there is not much research on IR infrastructure from this part of the world. [ABSTRACT FROM AUTHOR]

Microgrids represent a promising energy technology, because of the inclusion in them of clean and smart energy technologies. They also represent research challenges, including controllability, stability, and implementation. This article presents a dSPACE-control-platform-based implementation of a fixed-switching-frequency modulated model predictive control (M 2 PC) strategy, as an inner controller of a two-level, three-phase voltage source inverter (VSI) working in an islanded AC microgrid. The developed controller is hierarchical, as it includes a primary controller to share the load equally with the other power converter with its own local modulated predictive-based controller. All details of the implementation are given for establishing the dSPACE-based implementation of the control on a dSPACE ds1103 control platform, using MATLAB/Simulink for the controller design, I/O implementation and configuration with the embedded dSPACE's real-time interface in Simulink, and then using the ControlDesk software for monitoring and testing of the real plant. The latter consists of the VSI operating with  L C L  filters, and sharing an  R L  load with a paralleled VSI with exactly the same controller. Finally, the obtained experimental waveforms are shown, with our respective conclusions representing this work, which is a very valuable tool for helping microgrid researchers implement dSPACE-based real-time simulations. [ABSTRACT FROM AUTHOR]

The performance enhancement of the Induction Motor (IM) is a crucial and strenuous task. The Direct Torque Control (DTC) method is a common control strategy for boosting the IM drives and wildly implemented due to its merits including insensibility to motor parameters and fast response. However, the main shortage of the traditional DTC method is that it may lead to large flux and torque ripples. In this regard, this paper proposes an efficient control method called a Finite-State Predictive Torque Control (FS-PTC) which is based on multi objective optimization technique to overcome the shortage in the conventional DTC method. In addition to that a ranking approach is presented to assign the weighting factor in the cost function which directly affects the performance of system. The proposed ranking approach is based on elimination the weighting factor by replacing the single cost function with two different cost functions. The proposed FS-PTC is applied and tested using the dSPACE environment to validate its effectiveness and efficacy. From the experimental simulations, the performance of system is enhanced considerably where the torque and flux ripples are reduced with maintaining a constant switching frequency compared to the conventional DTC.

Objective. To elaborate an integrative proposal that reconciles notes and establishes foundations for the constitution of the Urban Agriculture Digital Library (UADL). Method. Using the Design Thinking methodology, this study searched for concepts and elements of digital libraries in seminal works on the subject: Arms (1995), Saracevic (2000), McCray and Gallagher (2001), Gonçalves et al. (2004), Vidotti and Sant'ana (2006) and Vicentini (2006). From the indications presented by the six papers evidenced. Results. It was identified, in all, eight elements that are essential to the concept of digital library and that, therefore, are preserved over time: data, metadata, information architecture, users, metrics, preservation, protocol and information services. These elements were applied in the planning and development of BDAU.

Direct Torque Control (DTC) presents an optimal solution to control the behaviors of the alternative motors, compared to other controls, because of several advantages offered by this technique, the speed overshoots, fluxes, and torque ripples remain the major factors which minimize the DTC robustness. The regulation speed in DTC is carried out by the classic Proportional Integrator Derivative (PID), which is known for its higher robustness in linear systems, except that in the case of non-linear systems, the PID controller gives poor reactions to variations in the system’s parameters. The best solutions adopted in this situation are often based on optimization algorithms that generate the controller’s gains in each period where there is an internal or external perturbation, adapting the behaviors of the PID against the system’s nonlinearity. For that reason, this work is focused on the theoretical studies and experimental validation on dSPACE Board DS1104 of the new proposed approach based on PID speed regulation, optimized by the Ant Colony Optimization algorithm (ACO) for DTC, applied to both sides of the Doubly Fed Induction Motor (DFIM), to overcome the previous drawbacks cited at the beginning. The new combined ACO-DTC strategy has been studied for optimizing the gains of the PID controller by using a cost function such as Integral Square Error (ISE). The proposed approach is implemented on Matlab/Simulink to validate the objectives adopted by this strategy. The simulation and experimental results extracted from Matlab and ControlDesk have proved the efficiency of the proposed ACO-DTC with the system’s nonlinearity, which attribute different enhancements in the global system performance.

In this study, a high power (75 kW) original driver and control algorithm has been developed for an electric passenger vehicle whose features can be used practically. It has been observed that some problems occur in the operation of the developed control algorithms in traction systems operating at high power. In this study, the solution methods of these problems are included. Firstly, the simulation model of an electrical vehicle was obtained by determining the basic parameters for a passenger electric vehicle. Then a brushless DC motor and drive system was determined for the electric vehicle and an original 75 kW DC-AC Converter (Inverter) in accordance with automotive standards has been designed and tested for the Brushless DC motor. Also, in the design and implementation phase, PID and Fuzzy control-based vehicle control software was developed in MATLAB/Simulink environment on the purpose of rapid prototyping and loaded on the DS1401 dSPACE based control system. It has been seen that through rapid prototyping, the appropriate controller development cycle time for the vehicle drastically reduced, which significantly has reduced the research and development costs. In the vehicle control algorithm, speed information is used as a reference input and brake information is used as feedback. The control signal generated by the controller is converted into PWM pulses for each phase and applied to the IGBT driver. These PWM pulses were used to switch the six IGBT power components used in the three-phase full-bridge DC-AC converter. Driving performance at the design stage has been studied for cases of starting, speed, reversal and load failure. Simulation and experimental results demonstrated the effectiveness of the driver and drive control system that were originally developed. When the system response was examined, it was revealed that the fuzzy logic control algorithm presented much better results than the PI and then the PID control algorithm. Simulation results and application results were consistent with each other and the system performance was successfully tested. Many protection circuits have been designed and configured in the system, with the control algorithms developed according to the problems arising in the operation of high-power systems, hardware add-ons for the operation of the high power (75kW) power-train. Safety and security infrastructures have been developed in both hardware and software for the appropriate certification in automotive standards. [ABSTRACT FROM AUTHOR]

Digital repositories play a crucial role in organizing and preserving vast collections of digital content. Efficiently ingesting large amounts of data into these repositories is a common challenge faced by institutions. This paper explores the use of bulk upload techniques in DSpace, an open-source digital repository software, to streamline the ingestion process and enhance repository management. We discuss the benefits of bulk upload in terms of time savings, metadata consistency, and scalability. Additionally, we delve into the technical aspects of implementing bulk upload in DSpace, covering the Simple Archive Format (SAF), metadata mapping, and handling of digital files. Furthermore, we highlight real-world examples and best practices for utilizing bulk upload in DSpace. By adopting this approach, institutions can significantly improve their efficiency in managing and preserving digital content, ensuring a seamless user experience, and facilitating knowledge dissemination. Here, an experimental method of research/case study technique is utilized to evaluate the efficiency and effectiveness of the design model for implementation of the bulk uploading of documents in Dspace at Bennett University is practiced. The feedback is gathered in order to identify the flaws and make the necessary improvements. Simple Archive Format (SAF) is a utility that converts Bitstream/Content files plus a metadata.csv file into a Simple Archive Format package, making bulk uploads to the DSpace repository simple. All question papers were digitized using a high-quality scanner, an Excel file with Dublin core information was created, and Excel was converted to CSV format in order to import all old question papers in bulk into the Bennett University Digital Repository Services. The study indicates that it is essential to pay close attention to the precise format of metadata leveraging the Dublin core and the file's location. It is an experiment conducted by the Bennett University Library and the research was confined to Bennett University digital repository. [ABSTRACT FROM AUTHOR]

This study aimed to determine how the usage and understanding of open-source digital repositories affect measurements. This paper examines a DSpace and EPrints case study at Fiji National University. The idea of a digital repository is essential in research communities. Facilitating research in an open-access setting is essential. Open-access digital library software such as DSpace, EPrints, and Greenstone can address these problems. In contrast, Information and Communication Technology (ICT) has fundamentally changed how individuals' access and engage with information. Since they provide accurate and up-to-date information and support an academic institution's primary objective, digital sources of information have become crucial to the current library collections in the academic environment. Nevertheless, as information and communication technology (ICT) has advanced, how individuals' access and engage with information has seen a revolutionary change, and the phrase "digital library" has proliferated throughout the library community. The effects of the pandemic, namely restrictions, closures, and other lockdown measures implemented to keep people safe and make it difficult or impossible to visit many locations and cultural events, have become increasingly evident with the advanced use of digital repositories in university libraries. Despite this, the epidemic has raised users' and researchers' awareness of digital access, making it more straightforward for people to obtain information, services, and other material resources online without considering the physical requirement to visit these places. Technological breakthroughs have caused significant changes in modern culture. The sharing and preserving of information, which has substantial worth and will last for decades, is essential for a generation's legacy. To gain skills for this software, professionals in the library and information science (LIS) area have gone through training on a variety of platforms. Universities and organizations can access digital research and educational materials thanks to the most popular institutional repository software products, DSPACE and EPrints. Other institutional repository software programs are available, subsequently, more original content in digital formats is produced and never released through conventional channels. Institutions and universities need to maintain their valuable assets. The purpose of this study is to examine the outcomes of increasing librarians awareness and use of DSpace and EPrints, two open-source digital repositories, as well as the value of training workshops for librarians at the Fiji National University. [ABSTRACT FROM AUTHOR]

Introduction: One of the forms of dissemination of technical memory occurs through Digital Libraries and Digital Repositories. These information environments can be developed and customized from various software. In Brazil, DSpace is one of the main systems used in the creation of Digital Libraries and Institutional Repositories, thus providing opportunities for the representation, dissemination, access and use of the information made available from these tools. Given such relevance, the information available in these information environments needs to be of quality, in order to ensure numerous contributions to organizations, as well as to their users. Objective: Considering the need to ensure the quality of the information available in Digital Libraries, this study aims to propose a model to foster the improvement of the quality of technical memory deposits in Digital Libraries implemented from the DSpace. Methodology: This is a qualitative and descriptive study, which makes use of the bibliographic survey technique in national and international databases. Results: Based on the bibliographic survey it was possible to propose the model of evaluation of the quality of deposits in Digital Libraries developed from the DSpace, thus presenting contributions to improve the quality of the information available in these environments so relevant to the dissemination of knowledge. Conclusion: The proposed model will allow interested parties to evaluate the quality of deposits made in Digital Libraries, especially those created through the DSpace software. [ABSTRACT FROM AUTHOR]

Technological transformation has been intensified by the migration of information media from physical to digital environments, raising the relevance of information organization in digital systems for a better browsing and user experience. Thus, this study aims to compare the elements of the information architecture organization system in the open access programs Greenstone, DSpace, Omeka, and Tainacan used for the implementation of digital libraries. In methodological terms, it was based on bibliographic and documentary research of the programs to carry out the analysis of the components of the organization system and the quali-quantitative approach. For this, the comparative method was also used, establishing the observation of similarities and differences between the selected software. In conclusion, the four components of the organization system, which are: exact schemas; ambiguous schemas; hybrid schema and structures; the ambiguous schema except the topic element, were not evidenced in the selected software. Regarding, the criteria of the knowledge organization system, relationships, cardinality and metadata are common to the implementation in all the selected software. Finally, it was possible to identify the elements of the Information architecture organization system, associated with sustainability and the context of digital collections. [ABSTRACT FROM AUTHOR]

This study presents an algorithm for estimating two-phase rotor reference frame currents using a single-current sensor. For proper vector control operation, at least two of three-phase current information is required. The single-current sensor algorithm is presented for vector-controlled interior permanent magnet synchronous motor drive to reduce the cost and increase reliability. dq-axes current formation method evaluates the two-phase currents in the stationary reference frame by sensing only one-phase current and speed/position information. The two-phase stationary reference frame currents, iβs current, are estimated using iqs* and iαs, i.e., constructed from single sensor information. D- and q-axes currents are obtained from i αs and is β*. These are used to close the current loop in the vector-controlled drive. Three- phase currents can be reconstructed from the estimated two-phase currents. This method is entirely independent of machine parameters and applicable to all kinds of permanent magnet synchronous motor machines. The presented algorithm is validated on MATLAB/SIMULINK platform. Some sample results are shown from an experiment performed on a prototype developed in the laboratory (using dSPACE 1104). [ABSTRACT FROM AUTHOR]

Purpose: The objective of the work is to develop and implement the original concept of Repository of Didactic Processes Data (RDPD) for universities. The task of the Repository is to handle formally organised content in a digital form, covering resources created in connection with didactic processes, and the origin of which is a university community. These data should be: as complete as possible, available on the Internet at any time and easy to find and retrieve, stored in commonly used formats, contain a clear indication of the stored resources, without any costs for the user downloading them. Design/methodology/approach: The concept of the Repository was developed on the basis of the results of consultations with the academic community – its primary target audience. Comments from the representatives of the Repository future main users were taken into account. An analysis of the existing available repository systems in terms of their functionality, adaptability to the specificity of data, and popularity was carried out in order to select the solution that could be the foundation for RDPD. Then, the following tasks were undertaken in the environment of the selected system: adapting the data schema developed for RDPD, the implementation of the operations of loading, browsing, and searching of data, and user management. Findings: As a result of research and analyses, DSpace was proposed as the basis for the RDPD system. The logical metadata layers as well as the technical implementation of the proposed Repository in the DSpace system were elaborated. Practical implications: The implementation of the RDPD system may significantly facilitate and support the university management process. Originality/value: There are many initiatives regarding institutional repositories within the higher education sector. However, there is no institutional repository dedicated strictly to the storage and management of data generated by university educational processes. The developed repository is the solution to the problem. [ABSTRACT FROM AUTHOR]

The article focuses on awareness of institutional repository (IR), and visibility of research output through IR to enhance the visibility of university research output in higher education institutions in Ghana. One hundred and fifteen librarians were selected using a quantitative methodology. Data were collected using a questionnaire, and the results were generated using descriptive statistics. The study found out that universities in Ghana mostly relied on the "mediatedarchiving" model during uploads of research output than self-archiving approach. Strategies to promote IR for its intended benefits include mandating academics and students to deposit intellectual content, linking publication metrics to academic promotions and aggressively enhancing awareness of the IR. Our paper concludes that information specialists need to be creative in sensitising researchers and the academic community regarding the visibility of their research output by using IR. [ABSTRACT FROM AUTHOR]

Microgrids represent a promising energy technology, because of the inclusion in them of clean and smart energy technologies. They also represent research challenges, including controllability, stability, and implementation. This article presents a dSPACE-control-platform-based implementation of a fixed-switching-frequency modulated model predictive control (M2PC) strategy, as an inner controller of a two-level, three-phase voltage source inverter (VSI) working in an islanded AC microgrid. The developed controller is hierarchical, as it includes a primary controller to share the load equally with the other power converter with its own local modulated predictive-based controller. All details of the implementation are given for establishing the dSPACE-based implementation of the control on a dSPACE ds1103 control platform, using MATLAB/Simulink for the controller design, I/O implementation and configuration with the embedded dSPACE’s real-time interface in Simulink, and then using the ControlDesk software for monitoring and testing of the real plant. The latter consists of the VSI operating with LCL filters, and sharing an RL load with a paralleled VSI with exactly the same controller. Finally, the obtained experimental waveforms are shown, with our respective conclusions representing this work, which is a very valuable tool for helping microgrid researchers implement dSPACE-based real-time simulations.

The space vector modulation (SVM) method was recently proposed and captured the interest of scientific research in the following years. In this paper, besides a brief review of the SVM methods proposed in the literature, a new SVM strategy based on the calculation of the minimum (Min) and maximum (Max) of three-phase voltages is proposed. The proposed SVM technique does not have to calculate the sector and angle, as is done in the traditional SVM technique. Therefore, it is the easiest technique to accomplish compared to the traditional SVM method and other existing methods. Compared with the traditional pulse width modulation (PWM), the advantage of using this new SVM strategy is that the scheme is simple and the total harmonic distortion (THD) value in the output of the two-level inverter is minimized. The technology has been simulated by MATLAB/Simulink, and then implemented on a real traditional two-level inverter using the dSPACE card. It is worth reporting the reduction obtained for THD using the proposed SVM technique (where THD is about 70%) compared to the traditional PWM technique (where THD is about 79.5%). [ABSTRACT FROM AUTHOR]

An adaptive cruise control system is highly used in conventional internal combustion engine vehicles, but due to the electrification of the vehicles, the adaptive cruise control system must be placed in relation with the electric motor control block. This paper presents the relationship between an adaptive cruise control system and the motor control in the case of an electric vehicle. An indirect filed-oriented control of an induction machine is considered for the electric traction system. The adaptive cruise control block computes the required acceleration to ensure the velocity set by the driver based on the set velocity, the actual velocity of the vehicle, a safe distance, and the relative distance between the host car and a leading car. The proposed system was implemented in MATLAB/Simulink and, also, in a low-scale laboratory experimental setup. The correct operation of the system was tested using a speed profile, and both systems, simulated and experimental, have the expected response. The velocity, acceleration, rotor speed, torque response, and relative and safe distance are the responses presented to prove the efficiency of the proposed implementation. [ABSTRACT FROM AUTHOR]