Search results for " Permanent"
showing 10 items of 144 documents
Comparison of three control drive systems for interior permanent magnet synchronous motors
2017
In a previous paper, we proposed a control strategy for interior permanent synchronous motors, which takes into account also the reduction of the motor power losses. The novelty of the suggested approach is that it takes into consideration the variations of all the motor parameters that have an influence on its efficiency. In order to verifyon the field the effectiveness of this new method, we implemented the proposed loss model algorithm in a control drive system and compared its performances, in terms of energy losses with respect to other conventional techniques.
Enhanced mathematical modelling of interior permanent magnet synchronous machines for loss minimization control
2020
Energy management is a fundamental facility for humanity. At present, the awareness that renewable energy cannot satisfy the entire energy needs of the community and that traditional energy sources have a limited duration makes it imperative to address the problem of their careful and responsible use. Therefore, the need for an intelligent and functional use of energy has led the technical-scientific community to concentrate its efforts on the issues of sustainable development and energy savings. The electric drives industrial sector has suffered this influence in a visceral way. This sector plays a leading role in the industrial frame as it is one of the main consumers of electricity. More…
Characterization of the parameters of interior permanent magnet synchronous motors for a loss model algorithm
2017
Abstract The paper provides the results of a detailed experimental study on the variations of the characteristics of an interior permanent magnet synchronous motor, when load, speed and/or magnetization conditions vary. In particular, the characterization is carried out by assessing, for several working conditions, the motor parameters that influence its efficiency. From the knowledge of the variability of these parameters, it is possible to develop a dynamic model of the motor, which accurately describes its behaviour and allows estimating the power losses for whatever speed and load. In order to validate the model, the values of the power losses obtained by using the model are compared wi…
Mixed Fault Classification of Sensorless PMSM Drive in Dynamic Operations Based on External Stray Flux Sensors
2022
This paper aims to classify local demagnetisation and inter-turn short-circuit (ITSC) on position sensorless permanent magnet synchronous motors (PMSM) in transient states based on external stray flux and learning classifier. Within the framework, four supervised machine learning tools were tested: ensemble decision tree (EDT), k-nearest neighbours (KNN), support vector machine (SVM), and feedforward neural network (FNN). All algorithms are trained on datasets from one operational profile but tested on other different operation profiles. Their input features or spectrograms are computed from resampled time-series data based on the estimated position of the rotor from one stray flux sensor t…
Les aménagements de voirie face aux préjudices commerciaux des riverains
2013
International audience
Repeated Load Triaxial Testing of Recycled Excavation Materials Blended with Recycled Phyllite Materials
2022
Recycled Excavation Materials (REM) are becoming viable alternative construction resources due to their economic benefits. However, REM may be composed of weak rocks, e.g., phyllites, limiting the use in a base layer. The present paper attempts to further the knowledge of the mechanical performance of REM by performing Repeated Load Triaxial Tests (RLTT). REM are mixed with Recycled Phyllite Materials (RPM) in systematic blends of 0%, 25%, 50%, and 100%. The batches’ resilient modulus (MR) and permanent deformation (PD) characteristics were assessed to establish the maximum RPM allowed into REM while maintaining the required performance. Hicks and Monismith’s and Uzan’s mo…
The magnet of the scattering and neutrino detector for the SHiP experiment at CERN
2019
The Search for Hidden Particles (SHiP) experiment proposal at CERN demands a dedicated dipole magnet for its scattering and neutrino detector. This requires a very large volume to be uniformly magnetized at B > 1.2 T, with constraints regarding the inner instrumented volume as well as the external region, where no massive structures are allowed and only an extremely low stray field is admitted. In this paper we report the main technical challenges and the relevant design options providing a comprehensive design for the magnet of the SHiP Scattering and Neutrino Detector.
Jednorazowe pozwolenie na stały wywóz zabytku za granicę z perspektywy kategorii wieku i wartości – ochrona dziedzictwa kulturowego a rynek sztuki w …
2019
Artykuł przedstawia problem wywozu zabytków za granicę. Analizie została poddana procedura wywozu zabytku na stałe w kontekście kategorii wieku i wartości obiektu. Autorzy prezentują nowy test VOH (Value of Heritage), który może być stosowany przez rzeczoznawców Ministra Kultury i Dziedzictwa Narodowego. Pomoże to w dużym stopniu obniżyć ryzyko wydania decyzji nienależycie uzasadnionych czy niekorzystnych dla zachowania narodowego dziedzictwa kultury w Polsce
Risk Factors Associated with Carious Lesions in Permanent First Molars in Children: A Seven-Year Retrospective Cohort Study
2020
The aim of this study was to evaluate the risk factors associated with the occurrence of caries in permanent teeth (PT) and in the permanent first molar (PFM) seven years after their eruption. Children born in 2005 who were enrolled in a Community Dental Program were included. A total of 278 children were enrolled. Evaluated risk factors were parental caries experience, educational level of the mother, routine medications, systemic diseases, dietary habits, toothbrushing frequency, existence of molar incisor hypomineralization (MIH) in the PT, and caries in the temporary teeth (TT). Associations between independent variables and the DMF-T (decayed, missing, and filled teeth in PT) and DMF-M…
Advanced Monitoring of Rotor Broken Bar in Double Squirrel Cage Induction Machines Based on Wavelet Analysis
2012
The diagnosis of induction machine faults is commonly realized through Motor Current Signature Analysis (MCSA), i.e. by classical spectrum analysis of the input currents. In case of large or double cage induction motors, rotor broken bars fault detection based on sideband current components may fail due to the presence of inter bar currents that reduce the degree of rotor asymmetry, leading to reduced relevance of these spectral components. But inter bar currents produce core vibrations in the axial direction, which can be detected using vibration analysis techniques, in order to overcome the limits of the classical MCSA for these purposes. In this paper, an advanced use of the Discrete wav…