Search results for "Electrical & Electronic Engineering"
showing 10 items of 483 documents
High Performance FOC for Induction Motors with Low Cost ATSAM3X8E Microcontroller
2018
In this paper the Authors present the Arduino Due board application for an induction motor field oriented control (FOC) algorithm. The low cost Arduino Due board is equipped with a ATSAM3X8E microcontroller that performs the algorithm calculation, data processing, current signals and speed/position data acquisition. The control algorithm has been developed with the help of the open source Arduino integrated development environment, whereas a user friendly control interface, used to manage the speed or position set point, has been developed in Java language by means of an other open source software, namely, Processing. An experimental test bed has been set up in order to validate the FOC sys…
A New Approach to Investigate Students’ Behavior by Using Cluster Analysis as an Unsupervised Methodology in the Field of Education
2016
The problem of taking a set of data and separating it into subgroups where the ele- ments of each subgroup are more similar to each other than they are to elements not in the subgroup has been extensively studied through the statistical method of cluster analysis. In this paper we want to discuss the application of this method to the field of education: particularly, we want to present the use of cluster analysis to separate students into groups that can be recognized and characterized by common traits in their answers to a questionnaire, without any prior knowledge of what form those groups would take (unsupervised classification). We start from a detailed study of the data processing need…
A Selective Change Driven System for High-Speed Motion Analysis.
2016
Vision-based sensing algorithms are computationally-demanding tasks due to the large amount of data acquired and processed. Visual sensors deliver much information, even if data are redundant, and do not give any additional information. A Selective Change Driven (SCD) sensing system is based on a sensor that delivers, ordered by the magnitude of its change, only those pixels that have changed most since the last read-out. This allows the information stream to be adjusted to the computation capabilities. Following this strategy, a new SCD processing architecture for high-speed motion analysis, based on processing pixels instead of full frames, has been developed and implemented into a Field …
A comparison of different DC-DC converters for energy storage management in nearly-Zero Energy Buildings
2020
In the recent years, there has been a notable interest towards renewable sources, energy saving and efficiency optimization, in order to reduce the damages brought by fine dust and greenhouse gases in terms of safety, health and environmental protection. In the building sector renewable sources and energy efficiency optimization are leading to a large scale employment of nearly-Zero Energy Buildings (n-ZEBs), meaning that the balance between produced and required energy is negligible. For a proper n-ZEB implementation, a power system architecture has to be accurately designed, according to the existing renewable sources, loads and storage systems. In this paper, an investigation on differen…
Diagnosis of Incipient Bearing Faults using Convolutional Neural Networks
2019
The majority of faults occurring in rotating electrical machinery is attributed to bearings. To reduce downtime, it is desired to apply various diagnostic methods so that bearing degradation can be detected in good time prior to a complete failure. The work presented in this paper utilizes a data-driven machine learning approach based on convolutional neural networks (CNNs) in order to diagnose different types of bearing faults. A one-dimensional CNN is trained on vibration signals and compared to a two-dimensional CNN trained in time-frequency domain using continuous wavelet transform (CWT). The proposed method is demonstrated on data collected from run-to-failure tests.The results show th…
Minimum power losses by using droop coefficients regulation method with voltage and frequency constraints in islanded microgrids
2018
In this paper, a droop coefficients regulation methodology is proposed for an islanded microgrid to optimize the power losses. Based on the P-f and Q-V relations to adjust the droop coefficients at every loading condition, the optimized operating set point generates minimum power losses operation while satisfying the constraints of voltage and frequency limitation. A 9-bus case study is here implemented to show the effectiveness of this new approach as well as the improved operation quality of the system.
Experimental Characterization of a Double Receiver Dynamic Wireless Charging System
2020
The aim of this work is the characterization of a dynamic wireless charging system low power prototype and the validation of a simplified mathematical model of the employed double D coils. The difference between a single receiver and a dual receiver system is also shown, highlighting how the last one can significantly reduce the costs of the charging infrastructure.
Vector representation of non-standard spellings using dynamic time warping and a denoising autoencoder
2017
The presence of non-standard spellings in Twitter causes challenges for many natural language processing tasks. Traditional approaches mainly regard the problem as a translation, spell checking, or speech recognition problem. This paper proposes a method that represents the stochastic relationship between words and their non-standard versions in real vectors. The method uses dynamic time warping to preprocess the non-standard spellings and autoencoder to derive the vector representation. The derived vectors encode word patterns and the Euclidean distance between the vectors represents a distance in the word space that challenges the prevailing edit distance. After training the autoencoder o…
Experimental Validation of a Novel Method for Harmonic Mitigation for a Three-Phase Five-Level Cascaded H-Bridges Inverter
2019
In modern high-power electrical drives, the efficiency of the system is a crucial constraint. Moreover, the efficiency of power converters plays a fundamental role in modern applications requiring also a limited weight, such as the electric vehicles and novel more electric aircraft. The reduction of losses pushes for systems with a dc bus and a high number of dc/ac converters, widespread in the vehicle, not burdened by a too expensive data processing system. The purpose of this article is to concur to reduce losses by proposing an innovative selective harmonic mitigation method based on the identification of the working areas where the reference harmonics present lower amplitudes. In partic…
EKF-based estimation and control of electric drivetrain in offshore pipe racking machine
2016
A typical challenge for electric drivetrains is to reduce the number of sensors required for control action or system monitoring. This is particularly important for electric motors operating in offshore conditions, since they work in hostile environment which often damages data acquisition systems. Therefore, this paper deals with verification and validation of the extended Kalman filter (EKF) for sensorless indirect field-oriented control (IFOC) of an induction motor operating in offshore conditions. The EKF is employed to identify the speed of the induction motor based on the measured stator currents and voltages. The estimated speed is used in the motor speed control mode instead of a ph…