Search results for "Hardware"
showing 10 items of 1372 documents
Enhanced flexible algorithm for the optimization of slot filling factors in electrical machines †
2020
The continuous development in the field of industrial automation and electric mobility has led to the need for more efficient electrical machines with a high power density. The improvement of electrical machines’ slot filling factors is one of the measures to satisfy these requirements. In recent years, this topic has aroused greater interest in the industrial sector, since the evolution of the winding technological manufacturing processes allows an economically sustainable realization of ordered winding arrangements, rather than random ones. Moreover, the manufacture of electrical machines’ windings must be preceded by an accurate design phase in which it is possible to evaluate the maximu…
CNN based Gearbox Fault Diagnosis and Interpretation of Learning Features
2021
Machine learning based fault diagnosis schemes have been intensively proposed to deal with faults diagnosis of rotating machineries such as gearboxes, bearings, and electric motors. However, most of the machine learning algorithms used in fault diagnosis are pattern recognition tools, which can classify given data into two or more classes. The underlined physical phenomena in fault diagnosis are not directly interpretable in machine learning schemes, thus it is usually called black/gray box models. In this study, convolutional neural networks (CNN) machine learning algorithm is proposed to classify gearbox faults, and the learning features of the CNN filters are visualized to understand the…
Performance Degradation of Discrete PID Controller for Digital Excitation Control System Due to Variation of Sampling Time
2019
Modern digital AVR are consisting PID controller in forward path ensures fast response in the event of disturbance. Digital keypad is used for setting PID gains to improve performance of the system. Digital PID controller reads the error signal at regular interval unlike analog controller that reads the error signal continuously. Regular interval at which digital processor reads error signal is called sampling time that has substantial effect on the performance of the controller and consequently affects the stability of the power system where synchronous generator using digital excitation system is connected in parallel. This paper addresses the issues of variation of sampling time on the p…
Design of a LLC Resonant Converter for Powering a PEM Electrolyzer
2021
International audience; This paper proposes the design of a LLC resonant converter to supply a proton exchange membrane (PEM) electrolyzer. The PEM requires a low voltage with high current, a reduced output voltage ripple, and an overdamped dynamic behavior of the converter to avoid voltage overshoots. The designed converter allows satisfying the design constraints, minimizing switching and reverse recovery losses; the efficiency is influenced mainly by the output rectifier's conduction losses.
Design and Study of a Wide-Band Printed Circuit Board Near-Field Probe
2021
Magnetic near-field probes (NFP) represent a suitable tool to measure the magnetic field level from a small electromagnetic interference (EMI) source. This kind of antenna is useful as a magnetic field probe for pre-compliance EMC measurements or debugging tasks since the user can scan a printed circuit board (PCB) looking for locations with strong magnetic fields. When a strong H-field point is found, the designer should check the PCB layout and components placement in that area to detect if this could result in an EMI source. This contribution focuses on analyzing the performance of an easy to build and low-cost H-field NFP designed and manufactured using a standard PCB stack-up. Thereby,…
Experimental study on the influence of controller firmware on multirotor actuator dynamics
2014
In this paper the dynamic response of a propeller actuator commonly used in hobby unmanned aerial vehicles is studied experimentally. It is shown that the choice of electronic speed controller firmware has a significant effect on the overall actuator dynamics. Six different scenarios are tested: 1+2) Rising/falling step response with the standard firmware of the Hobbyking F30a, 3+4) Rising/falling step response with firmware from Simon Kirby/GitHub and 5+6) Rising/falling step response with firmware from Simon Kirby/GitHub including complementary Pulse-Width-Modulation (PWM) switching. Experimental results show a significant difference in actuator dynamics depending on the chosen firmware. …
Formation of Hematite Nanotubes by Two-Step Electrochemical Anodization for Efficient Degradation of Organic Pollutants
2016
[EN] Nowadays, hematite (alpha-Fe2O3) has emerged as a promising photocatalyst for efficient degradation of organic pollutants due to its properties such as suitable band-gap (similar to 2.1 eV), stability against photocorrosion, abundance and low cost. However, some drawbacks such as low carrier mobility and short hole diffusion length limit its efficiency. In order to overcome these issues, self-ordered nanotubes can be synthetized. Anodization is one of the simplest and most economic techniques to produce nanostructures with high control. In the present study, self-ordered hematite nanotubes were synthetized by two-step electrochemical anodization. In two-step anodization, a first-step w…
Influence of the Heating Rate on the Annealing Treatment of Iron Oxide Nanostructures Obtained by Electrochemical Anodization under Hydrodynamic Cond…
2017
[EN] Iron oxide nanostructures are promising materials for photoelectrochemical applications such as water splitting. In this work, electrochemical anodization of iron is used to form different iron oxide nanostructures, and the influence of different anodization parameters was studied in order to find the most suitable nanostructure for photocatalysis applications. On the one hand, hydrodynamic conditions were evaluated by stirring the electrode at different rotation speeds during the electrochemical anodization to check their influence on the formation of the nanostructures. On the other hand, different heating rates during the annealing treatment were studied for obtaining efficient iron…
Surviving task interruptions: Investigating the implications of long-term working memory theory
2006
Typically, we have several tasks at hand, some of which are in interrupted state while others are being carried out. Most of the time, such interruptions are not disruptive to task performance. Based on the theory of Long-Term Working Memory (LTWM; Ericsson, K.A., Kintsch, W., 1995. Long-term working memory. Psychological Review, 102, 211-245), we posit that unless there are enough mental skills and resources to encode task representations to retrieval structures in long-term memory, the resulting memory traces will not enable reinstating the information, which can lead to memory losses. However, once encoded to LTWM, they are virtually safeguarded. Implications of the theory were tested in…