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Abstract

The proposed study is improvised value-engineered modifications for the basic interleaved boost converter (IBC) by including relevant modifications in circuits, which is expected for a better performance in switching with reduction in losses. The newly modified IBC circuit with insulated gate bipolar transistor (IGBT) along with converter has been experimented by simulations and the results are tabulated to modified IBC with metal oxide silicon field effect transistors. Further experimental analysis and validations of the proposed simulation with hardware developed adopting model SKM195GB066D consisting of IGBTs is presented. This study further enhances and summarises the optimum utilisation and the performance of IBC with the proposed IGBT modules that synchronises power diode. Enhancing the simulation outcomes, the hardware is proposed and developed to be tested for a load up to 1.5 kW with the evaluation of key parameters such as efficiency of the converter.

Abstract

Aviation has, over the years, become an inseparable element of human life. Airplanes are very commonly used for various tasks, such as transport of passengers and goods, military attack and defence, rescue, recreation and so on. In spite of the many advantages of aviation, one cannot ignore its disadvantages. The most important disadvantages of aviation are the emissions that cause atmospheric pollution and noise. Additionally, one should remember about the decreasing stocks of non-renewable fuels. These drawbacks affect human health and the natural environment. Therefore, a good alternative to conventional drive units in aircraft may turn out to be electric drive units in the near future. The aim of this article is to check the extent to which today’s knowledge and technology allow the use of electric drive units instead of conventional aircraft drive units. This article presents the concept of electric aircraft, from the electric drive unit to its power supply system. The feasibility of designing an electric jet drive unit for a passenger aircraft was analysed based on the performances of PZL 104 Wilga 35 and Boeing B787 Dreamliner.

Abstract

A 4-level flying capacitor converter (FCC) operation is considered on a base of discrete state-space model. A transition matrix is obtained for a pulse width modulation (PWM) period for large normalised voltage command values [1/3, 1). The transition matrix elements are expanded into power series by small parameters. The matrix eigenvalues are presented in the form of power series as well. Six separate transients are constructed for six possible initial FCC states on a PWM period. Inductor current and capacitors’ voltage transients are found for the voltage source power-up as the arithmetic average of the six separate transients. Finally, the discrete solutions are replaced by equivalent continuous ones. Simple and accurate formulas for inductor current and capacitors’ voltage transients demonstrate good agreement with simulation results.

Abstract

A 4-level flying capacitor converter (FCC) operation is considered on a base of discrete state-space model. A transition matrix is obtained for a pulse width modulation (PWM) period for small normalised voltage command values [0, 1/3]. The transition matrix elements are expanded into power series by small parameters. The matrix eigenvalues are presented in the form of power series as well. Six separate transients are constructed for six possible initial FCC states on a PWM period. Inductor current and capacitors’ voltage transients are found for the voltage source power-up as the arithmetic average of the six separate transients. Finally, the discrete solutions are replaced by equivalent continuous ones. Simple and accurate formulas for inductor current and capacitors’ voltage transients demonstrate good agreement with simulation results.

Abstract

Over the past few years, interest and research in wireless power transfer (WPT) have been rapidly incrementing, and as an effect, this is a remarkable technology in many electronic devices, electric vehicles and medical devices. However, most of the applications have been limited to very close distances because of efficiency concerns. Even though the inductive power transfer technique is becoming relatively mature, it has not shown near-field results more than a few metres away transmission. This review is focused on two fundamental aspects: the power efficiency and the transmission distance in WPT systems. Introducing the principles and the boundaries, scientific articles will be reviewed and discussed in terms of their methods and respective challenges. This paper also shows more important results in efficiency and distance obtained, clearly explaining the theory behind and obstacles to overcome. Furthermore, an overlook in other aspects and the latest research studies for this technology will be given. Moreover, new issues have been raised including safety and security.

Abstract

Based on Gauss’ law for the electric field, new formulas were deduced, that enable for the first time the writing of an analytical formula of the built-in potential of implanted and diffused semiconductor junctions. Consequently, in this work is devised a measurement technique for the built-in potential of such junctions. Such measurement is useful because new semiconductor materials besides silicon are more and more used today, like silicon-carbide (SiC) and gallium-nitride (GaN), which have larger bandgap and junction built-in potential. Finding the built-in potential helps adjusting the computer assisted design (CAD) tools and validates the simulation of such wide-bandgap devices.

Abstract

In this work, we present a new fuzzy second-order sliding mode controller (FSOSMC) for wind power transformation system based on a doubly-fed induction generator (DFIG) using intelligent space vector pulse width modulation (SVPWM). The proposed command strategy combines a fuzzy logic and a second order sliding mode control (SOSMC) for the DFIG command. This strategy presents attractive features such as chattering-free, compared to the conventional first and second order sliding mode techniques. The use of this method provides very satisfactory performance for the DFIG command. The effectiveness of this command strategy is proven through the simulation results.

Abstract

Automation of industrial activities aims to improve the efficiency of the productive processes while reducing costs and increasing safety. In industrial laundries, detergent management is a key factor that can lead to severe economic and environmental impacts if left uncontrolled. This paper documents the solution devised for an integrated detergent control and supervision system based on Internet-of Things paradigms. This solution follows from a problem put forward by the laundry services of Santa Casa da Misericórdia de Bragança, located in Portugal, to the Polytechnic Institute of Bragança. In order to keep track of the detergent in a centralised dispensing system, a Wi-Fi based measurement system was developed which enables real-time monitoring of the chemicals level. In order to facilitate the physical installation of the developed hardware, a custom-made enclosure was designed and 3D printed. The acquired data is then sent to a database connected to a data processing web-based platform which is responsible for the analytics.

Abstract

Development of increasingly efficient production methods is a competiveness driving factor for any company. Today, many of these improvements include the integration of technology-based solutions into processes traditionally operated by humans. In this context, the present work aims to report the controller performance of a prototype developed for semi-automatic sewing stations. This project was fostered by “Factory Play”, a Portuguese company that produces inflatable structures, under the technical supervision of the Polytechnic Institute of Bragança. At the present time, the sewing station travel speed is regulated by an embedded PID controller that has been previously tuned using classical methods. However, even if the overall performance is currently acceptable, additional experiments were made regarding the use of evolutionary based algorithms to attain a better dynamic response and flexibility. This article present the results obtained using those methods where it is possible to confirm that the use of evolutionary algorithm will simplify the design process while consistently leading to a suitable solution.

Abstract

Machine-learning techniques allow to extract information from electroencephalographic (EEG) recordings of brain activity. By processing the measurement results of a publicly available EEG dataset, we were able to obtain information that could be used to train a feedforward neural network to classify two types of volunteer activities with high efficiency.