21 results on '"Gerbaud, Laurent"'
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2. Injectionless Acoustic-Noise-Based PMSM Sensorless Control Using RCPLL for Improved Estimation Performance
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Malekipour, Amirhossein, Corne, Adrien, Garbuio, Lauric, Granjon, Pierre, and Gerbaud, Laurent
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This article introduces an injectionless approach for acoustic-noise-based sensorless control of the permanent magnet synchronous machine. Replacing the high-frequency injection, the pulsewidth modulation (PWM) voltages are used as the basis for the method implementation. The mathematical model of PWM with considering the deadtime effect is first presented. Then, its impact upon the harmonics of current, magnetic fields, and generated radial forces is detailed. It is experimentally verified that in the presence of deadtime, unlike the contaminated current profile, there are merely specific-order speed-dependent components appeared in the acoustic noise spectrum, which is a clear bonus for signal processing precision and estimation performance. Moreover, a novel phase-locked loop (PLL) topology comprising a resonant-controller-based feedforward compensation block (RCPLL) is proposed. This compensation block is integrated within the PLL, by which the extra harmonics in the PLL error are directly suppressed, and therefore, the estimation performance is noticeably enhanced. The robustness of the proposed sensorless algorithm, alone, is verified experimentally under different conditions, and then, the estimation performances with and without the proposed RCPLL are compared.
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- 2024
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3. A Closed-Loop PMSM Sensorless Control Based on the Machine Acoustic Noise
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Malekipour, Amirhossein, Corne, Adrien, Garbuio, Lauric, Granjon, Pierre, and Gerbaud, Laurent
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In this article, a novel sensorless control for permanent magnet synchronous machine (PMSM) using its radiated acoustic noise is proposed in which a high-frequency voltage signal is superimposed upon the fundamental excitation and the machine response to such excitation is studied. First, the analytical equations describing the field formation within the airgap leading to the generation of radial forces and acoustic noise are extensively investigated. In the next step, resulting harmonics in the acoustic noise waveform caused by the injected signals are predicted. Then it is experimentally verified that, depending on the machine structure, there will be some distinctive sidebands around the injected frequency directly related to the fundamental synchronous frequency. Acoustic noise waveform is highly distorted and sensitive to the environment; so a proposed four-stage signal processing algorithm containing two self-adaptive band-pass filters are used to safeguard the signal against unwanted distortions and flawlessly extract the rotor position information. Robustness and effectiveness of this method are verified experimentally in various operating conditions.
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- 2023
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4. Ce que la Covid-19 nous apprend sur la modélisation des épidémies
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Mathiot, Jean-François, Gerbaud, Laurent, Breton, Vincent, Mathiot, Jean-François, Gerbaud, Laurent, and Breton, Vincent
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L’épidémie de Covid-19 se transmet par les voies respiratoires. Ce mode de transmission dépend essentiellement des relations sociales entre individus, par opposition aux épidémies dont l’élément pathogène est transmis à longue distance, comme par exemple par l’eau.
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- 2022
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5. Sensitivity Analysis Using the Virtual Work Principle for 2-D Magnetostatic Problems
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Brun, Olivier, Chadebec, Olivier, Ferrouillat, Pauline, Niyonzima, Innocent, Siau, Jonathan, Meunier, Gerard, Gerbaud, Laurent, Vi, Frederic, and Le Floch, Yann
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The sensitivity analysis of electromagnetic quantities such as the magnetic force and torque is a crucial step when optimizing electromagnetic devices with gradient-based optimizers. This article provides an analytical derivation of those two quantities using the virtual work principle in a finite element package. It is suitable for any kind of optimization. A focus on the particular use of this sensitivity on shape optimization is presented. The development and validation of the method is detailed in this case. Finally, it is applied to the shape optimization of a switch reluctance motor (SRM) to improve its performances.
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- 2023
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6. Non-anemic iron deficiency: correlations between symptoms and iron status parameters
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Beatrix, Julien, Piales, Claire, Berland, Pauline, Marchiset, Eric, Gerbaud, Laurent, and Ruivard, Marc
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Objectives: To register all symptoms reported by non-anemic menstruating women, and examine the links between these symptoms and iron status parameters available including serum ferritin (SF) in primary care. Subjects and methods: In this cross-sectional study, we collected clinical and biological data from 780 French menstruating women aged 18–50 years. The data included an anonymous questionnaire (biometric information, physical and cognitive symptoms, reduction in physical performance, current quality of life with SF-36 questionnaire) and seven biological parameters available in primary care. We excluded women with anemia (hemoglobin < 12 g/dl) or chronic disease. Correlations were studied for 554 participants in bivariate analysis (BVA) and multivariate analysis (MVA), with adjusted odds ratio (OR). Receiver operating characteristic (ROC) curves were established for significant correlations in MVA (p< 0.05). Results: Among these 554 non-anemic women included, 304 (54.9%) had SF level below 50 µg/l, 103 (18.6%) had SF level below 20 µg/l, and 60 (10.8%) had SF level below 15 µg/l. Iron deficiency was significantly correlated with recent hair loss for SF ≤ 15 µg/l (OR = 2.19 with p= 0.02 in MVA) and SF ≤ 20 µg/l (OR = 2.26 with p< 0.01 in MVA). SF ≤ 20 µg/l was also correlated with limitations due to emotional problems according to SF-36 questionnaire (p= 0.01 in MVA). SF ≤ 50 µg/l was significantly correlated with restless legs syndrome (OR = 2.82 with p= 0.01 in MVA). Only one ROC curve for restless legs syndrome could suggest an optimal SF cut-off point at 39 µg/l (sensitivity 73%, specificity 61%). Conclusion: We identified two symptoms significantly more reported by non-anemic iron-deficient menstruating women: recent hair loss for serum ferritin (SF) ≤ 20 µg/l and restless legs syndrome for SF ≤ 50 µg/l. Non-anemic iron deficiency may also impact their quality of life, but further investigation is needed. If one of these symptoms is reported in primary care, the possibility of a symptomatic iron deficiency cannot be ruled out, and iron supplementation should be considered.
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- 2022
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7. Modelling the determinants of health and cancers as perceived by children: using imagery as a mediator of expression and narration
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Gay, Chloé, Deyra, Maeliane, Berland, Pauline, Gerbaud, Laurent, and Pizon, Frank
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ObjectivesTo model and analyse conceptions of determinants of health and cancer that are expressed and perceived by school children aged 6–11 based on a multiphase qualitative protocol.MethodologyThis is a multicentric, qualitative study of human and social sciences conducted among school children aged 6–11 years old. Two different tools were used, e.Photoexpression and Photonarration, in four French schools. This innovative and exploratory method addresses global health during the first phase (e.Photoexpression) and the theme of cancer during the second phase (Photonarration). The children express themselves through photography and narration.Results1498 qualitative productions were made by 381 children aged 6–11 years old. The analysis of these productions of expression and narration through images allowed modelling of determinants of health and cancer as perceived by children through 7 fields and 28 categories. The conceptions of determinants of health and child cancer refer to rationalities that are centred on individual determinants (76%), minimise environmental determinants (20%) and conceal the parameters of access to healthcare and social services (3%).DiscussionThese findings provide new data to the international literature on children’s perceptions of determinants of health and cancer. These research findings, which can be applied to interventions and current practices, will enable prevention workers to act more effectively, closer to children’s perceptions and needs.
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- 2021
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8. Feelings and expectations in endometriosis: Analysis of open comments from a cohort of endometriosis patients
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Chauvet, Pauline, Guiguet-Auclair, Candy, Comptour, Aurélie, Denouël, Amélie, Gerbaud, Laurent, Canis, Michel, and Bourdel, Nicolas
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Endometriosis symptoms may have a negative effect on health-related quality of life (HRQoL). Analyses of open comments are known to be a key source of information and support. The authors aimed to analyse open comments associated with a validation scale study, in order to ascertain whether the questionnaires allowed an adequate exploration of patient preoccupations and in so doing define important quality of life themes not assessed in HRQoL scales.
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- 2018
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9. Positive and cost-effectiveness effect of spa therapy on the resumption of occupational and non-occupational activities in women in breast cancer remission: A French multicentre randomised controlled trial.
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Mourgues, Charline, Gerbaud, Laurent, Leger, Stéphanie, Auclair, Candy, Peyrol, Fleur, Blanquet, Marie, Kwiatkowski, Fabrice, Leger-Enreille, Anne, and Bignon, Yves-Jean
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Purpose of the research The main aim was to assess the effects of a spa treatment on the resumption of occupational and non-occupational activities and the abilities of women in breast cancer remission. A cost-effectiveness analysis (CEA) was also performed. Methods and sample A multicentre randomised controlled trial was carried out between 2008 and 2010 in the University Hospital of Auvergne and two private hospitals in Clermont-Ferrand, France. Eligible patients were women in complete breast cancer remission without contraindication for physical activities or cognitive disorders and a body mass index between 18.5 and 40 kg/m 2 . The intervention group underwent spa treatment combined with consultation with dietician whereas the control underwent consultations with the dietician only. Of the 181 patients randomised, 92 and 89 were included in the intervention and the control groups, respectively. The CEA involved 90 patients, 42 from the intervention group and 48 from the control group. Key results The main results showed a higher rate of resumption of occupational activities in the intervention group ( p = 0.0025) and a positive effect of the intervention on the women's ability to perform occupational activities 12 months after the beginning of the study ( p = 0.0014), and on their ability to perform family activities ( p = 0.033). The stay in a thermal centre was cost-effective at 12 months. Conclusions Spa treatment is a cost-effective strategy to improve resumption of occupational and non-occupational activities and the abilities of women in breast cancer remission. [ABSTRACT FROM AUTHOR]
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- 2014
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10. A caregiver educational program improves quality of life and burden for cancer patients and their caregivers: A randomised clinical trial.
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Belgacem, Bénédicte, Auclair, Candy, Fedor, Marie-Christine, Brugnon, David, Blanquet, Marie, Tournilhac, Olivier, and Gerbaud, Laurent
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Abstract: Purpose of the research: The French setting, including laws and guidelines, advocates greater involvement of informal caregivers in the care of cancer patients to protect the caregivers from depression, distress, and a decrease in their quality of life. This study aimed to assess the efficacy of a caregiver educational programme by measuring two outcomes: patients' and caregivers' quality of life and caregivers' burden. Methods and sample: A multicentre randomised controlled trial was performed in six oncology wards in French hospitals. Eligible patients had a cancer, a main caregiver, allowed their caregivers' involvement, and received an inclusion agreement by a doctor/psychologist dyad. The experimental group participated in an educational programme performed by nurses to improve their skills in meal support, nursing care, welfare care, or symptom management. The SF36 and the Zarit burden scales were used to measure quality of life and caregivers' burden at the beginning and at the end of the study. Key results: 67 patients were randomised and 33 were included in the experimental group. Evolution scores, which measured the difference between baseline and final scores, showed an improvement in patients' and caregivers' quality of life and an alleviated burden for experimental group caregivers. Conclusions: An educational programme for caregivers encourages the involvement of patients, informal caregivers and health-care providers in a triangular relationship which enhances the quality of life of patients and caregivers alike and decreases caregivers' burden. Care organisation should therefore be rethought as a triangular relationship between patients, caregivers and health-care providers, with nurses as the mainstay. [Copyright &y& Elsevier]
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- 2013
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11. Contribution à la modélisation des convertisseurs statiques pour la simulation à topologie variable
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Sahraoui, Omar, Gerbaud, Laurent, Normand, Olivier, Roudet, James, Sahraoui, Omar, Gerbaud, Laurent, Normand, Olivier, and Roudet, James
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Cet article propose une méthode simple et structurée pour la modélisation des convertisseurs statiques par des modèles à topologie variable, en vue de la simulation d'associations machine-convertisseur-commande complètes. Cette démarche s'appuie sur la notion de cellule de commutation pour permettre de dégager une décomposition modulaire du convertisseur en structures élémentaires, faciles à étudier, qui seront appelées bras indépendants. Ces derniers sont stockés en bibliothèque (sous forme d'algorithme ou programme, et sous forme de modèle), pour être réutilisés dans l'étude d'autres convertisseurs.
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- 1993
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12. Prevalence of Iron Deficiency and Health-related Quality of Life among Female Students.
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Grondon, Marie-Ange, Ruivard, Marc, Perrève, Anne, Derumeaux-Burel, Hélène, Perthus, Isabelle, Roblin, Julie, Thiollières, Fabrice, and Gerbaud, Laurent
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This article presents a study conducted to determine the prevalence of iron deficiency and examine the relationship between iron status and health-related quality of life among female students. Iron deficiency is one of the most common nutritional disorders in women and adolescents. The methodology and results of the study are discussed.
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- 2008
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13. Un questionnaire de satisfaction des patients hospitalisés pour embolie pulmonaire
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Breuil, Nadine, Gabriac, Camille, Belgacem, Bénédicte, Auclair-Guiguet, Candy, Gerbaud, Laurent, Dublanchet, Nicolas, and Schmidt, Jeannot
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L’objectif principal de ce travail est la construction d’un questionnaire de satisfaction des patients atteints d’embolie pulmonaire (EP) sur leur parcours de soins depuis l’admission aux urgences jusqu’à la 1reconsultation de suivi fixée entre la 4eet 6esemaine.
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- 2022
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14. An Experimental Investigation of Drilling Performance Improvement Using Reaming While Drilling
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Roohi, Abbas, Ashena, Rahman, Thonhauser, Gerhard, Finkbeiner, Thomas, Gerbaud, Laurent, and Rasouli, Vamegh
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This work investigates the drilling performance by reaming while drilling (RWD) using a dual-body bit and compared it with conventional drilling by a standard drilling bit. The dual-body bit consisted of a 2.45-in. pilot bit located at a short distance ahead of a 2.47 × 3.97-in. reamer. Conducting a series of drilling experiments at a simulation drilling rig with full monitoring sensors, we further studied the drilling performance as a function of the distance between the pilot bit and the reamer. This distance is a greatly important parameter affecting mud diffusion and the resultant change in pore pressure and stress. A method was devised to eliminate the drill-string vibration and its effect on the drilling performance and the energy consumed. The mechanical-specific energy (MSE) calculated for each case was considered as a drilling performance indicator. Using two laboratory experiments as well as analytical thermo-poro-elastic calculations of the Mechanical Specific Energy (MSE), the MSE changes were monitored and recorded. Comparison of this drilling performance indicator was used in both the RWD and the conventional drilling assembly to analyze the effect of RWD. Based on the results, with increasing the distance between the pilot bit and reamer, there is an increase in improvement of drilling performance in terms of MSE reduction. The best drilling performance indicator (MSE reduction of 84%) was observed with the greatest distance between the pilot bit and the reamer of 43.3 cm. The best drilling performance indicator (MSE reduction of 84%) was observed with the distance between the pilot bit and the reamer of 43.3 cm. This is considered a novel finding in reaming while drilling.
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- 2022
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15. Prevalence of Iron Deficiency and Health-related Quality of Life among Female Students
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Grondin, Marie-Ange, Ruivard, Marc, Perrève, Anne, Derumeaux-Burel, Hélène, Perthus, Isabelle, Roblin, Julie, Thiollières, Fabrice, and Gerbaud, Laurent
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Objective:To investigate prevalence of iron deficiency and examine the relationship between iron status and Health-related Quality of Life among female students.Design:Cross-sectional study.Subjects and Setting:Data were collected from 543 female students, aged 17 to 38 years, attending University or secondary schools in Clermont-Ferrand (France) and its metropolitan area. Three groups were defined, according to the rate of serum ferritin: iron deficient (serum ferritin <15μg/L), iron depletion borderline (serum ferritin 15–20 μg/L), and iron replete (serum ferritin > 20 μg/L). Those 3 groups of menstruating female students were compared in terms of health-related quality of life using univariate analysis.Measures of Outcome:Health-related Quality of Life based on SF-36 questionnaire, and iron status measured by serum ferritin.Results:The prevalence of iron deficiency was 19.3 %, the prevalence of borderline iron status was 11.4 %. Regarding the SF-36 questionnaire, the only significant difference between iron deficient and iron replete female students concerned the dimension reflecting ‘general health', which was significantly lower in iron deficient group (p= 0.015).Conclusion:Iron deficiency seems to impair the perceived general health in female students. Further research should be conducted on this little known subject.
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- 2008
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16. An observational study of multi-disciplinary co-design – application to an electromechanical device
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Marin, Philippe, Gerbaud, Laurent, Mechekour, El-Hadi, and Masclet, Cedric
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This paper deals with the observational study of a multi-disciplinary and collaborative design project to produce an electromechanical plunger. The design of the device was carried out by students from different disciplines, in their final year. It was co-located and non co-located. Synchronous and asynchronous tasks were observed and several studies carried out with various scenarios. The aims of the study are to produce qualitative analysis based on the observations made, to prepare observational studies and quantitative analyses in an industrial context and to specify dedicated tools for the support of non co-located collaborative design. In this way, the paper presents a bibliographic study concerning various empirical approaches for observational studies of collaborative design. The successive observational studies are detailed: context, scenarios, tools, actors, recording means. A global qualitative analysis is finally proposed, highlighting the key parameters for the building of an industrial case observation.
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- 2007
17. CoreLab a componentbased integrated sizing environment
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Fischer, Vincent and Gerbaud, Laurent
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- 2005
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18. Using the Short Form-36 with Multiple Sclerosis Patients in Five Countries: A Cross-Cultural Comparison
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Pfennings, Lilian, Cohen, Leo, Miller, Deborah, Gerbaud, Laurent, Vleugels, Luc, Freeman, Jenny, Vernay, Didier, Biolay, Sylvie, Ketelaer, Pierre, Thompson, Alan, Polman, Chris, and van der Ploeg, Henk
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Questionnaires measuring health-related quality of life are increasingly used in international studies of medical effectiveness. It is important to know if data from these instruments are comparable across countries. We initiated a collaboration among five research groups—from the USA, The Netherlands, Belgium, France, and the UK—in the field of health-related quality of life in multiple sclerosis. All groups used the 36-item Short Form Health Survey. The goal of our study was to make a cross-cultural comparison. In the five countries under study the sample size varied from 50 to 134 patients with multiple sclerosis. The survey was completed by a total of 457 patients, who were heterogeneous in relation to age, duration of illness, severity and type of multiple sclerosis. There appeared to be major differences among the samples in scores on each of the eight scales. These findings may be influenced by differences in method of recruitment, demographic and disease-related characteristics, administration, and cultural factors. After having performed a number of analyses, it appeared that the differences were mainly attributable to sampling effects; however, cultural influences could not be excluded.
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- 1999
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19. PROBLEMS IN COMPUTING SPECTRA GENERATED BY PWM INVERTERS FOR OPTIMIZATION OF ELECTRICAL DRIVES
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Groud, Alain, Gerbaud, Laurent, Rognon, Jean-Pierre, and Roudet, James
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This paper deals with the problems encountered in the study of the harmonics generated by a converter supplying an electrical drive. We are looking for a method easy to use, accurate and general enough to cover situations with different level of hypotheses. This difficult problem is studied in a basic case
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- 1998
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20. PROBLEMS IN COMPUTING SPECTRA GENERATED BY PWM INVERTERS FOR OPTIMIZATION OF ELECTRICAL DRIVES
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Groud, Alain, Gerbaud, Laurent, Rognon, Jean-Pierre, and Roudet, James
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This paper deals with the problems encountered in the study of the harmonics generated by a converter supplying an electrical drive. We are looking for a method easy to use, accurate and general enough to cover situations with different level of hypotheses. This difficult problem is studied in a basic case
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- 1998
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21. Contribution ? la mod?lisation des convertisseurs statiques pour la simulation ? topologie variable
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Sahraoui, Omar, Gerbaud, Laurent, Normand, Olivier, and Roudet, James
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This paper presents a simple and structured method of static converter modelling with variable topology, for the simulation of controlled converter-machine drives. The methodology is based on the notion of switching cells which enables a modular decomposition of converters in structures easy to be studied and henceforth called independent converter legs. These independent legs will be stored in libraries (algorithms or programs, and models) in order to be re-used for the study of other converters. Cet article propose une m?thode simple et structur?e pour la mod?lisation des convertisseurs statiques par des mod?les ? topologie variable, en vue de la simulation d'associations machine-convertisseur-commande compl?tes. Cette d?marche s'appuie sur la notion de cellule de commutation pour permettre de d?gager une d?composition modulaire du convertisseur en structures ?l?mentaires, faciles ? ?tudier, qui seront appel?es bras ind?pendants. Ces derniers sont stock?s en biblioth?que (sous forme d'algorithme ou programme, et sous forme de mod?le), pour ?tre r?utilis?s dans l'?tude d'autres convertisseurs.
- Published
- 1993
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