1,721,001 research outputs found
A DSP-based real-time simulation equipment for fast motor control development
No full text"This work presents a rapid motor control prototyping technique based on the development of a real-time simulation environment structured on a DSP architecture. The considered case study refers to an Interior Permanent Magnet synchronous motor (IPM) drive arranging a field oriented speed control with the optimization of the torque-to-current ratio and the decoupling of the feeding voltages. The main topics of this work are related with the construction of the real-time simulation platform and with the implementation issues coming from the use of a hardware DSP-based setup. In particular it will be shown how such a kind of simulation architecture can model very closely the real behaviour of a controlled IPM drive and consequently how it can be used to properly tune the control algorithm without the needing of using the real motor drive saving this way a lot of deployment time."This work presents a rapid motor control prototyping technique based on the development of a real-time simulation environment structured on a DSP architecture. The considered case study refers to an Interior Permanent Magnet synchronous motor (IPM) drive arranging a field oriented speed control with the optimization of the torque-to-current ratio and the decoupling of the feeding voltages. The main topics of this work are related with the construction of the real-time simulation platform and with the implementation issues coming from the use of a hardware DSP-based setup. In particular it will be shown how such a kind of simulation architecture can model very closely the real behaviour of a controlled IPM drive and consequently how it can be used to properly tune the control algorithm without the needing of using the real motor drive saving this way a lot of deployment time. © 2012 IEEE
Analysis of fault-tolerant PM motors with independent phases by finite element method
No full textThis paper presents the finite element analysis of a multiphase permanent-magnet motor designed to have independent phases structure according to the principles of fault tolerance. The goal of the study is to verify and quantify the independence of the phases from the electromagnetic point of view, one of the key requirements of fault-tolerant machines. The case study refers to a five-phase permanent-magnet motor designed for an aircraft flap application. The typical operating conditions of motors designed to operate in fault tolerant environments are considered, such as the opening of one or more phases after the occurrence of a failure. The actual performance of the multiphase motor is compared to that achieved by the superposition of the effects of each phase fed independently, which is the straightforward approach in usual modeling. The results demonstrate that modeling by independent phases leads to negligible errors in almost all the operating conditions
Analysis of fault-tolerant PM motors with independent phases by finite element method
No full textThis paper presents the finite element analysis of a multiphase permanent-magnet motor designed to have independent phases structure according to the principles of fault tolerance. The goal of the study is to verify and quantify the independence of the phases from the electromagnetic point of view, one of the key requirements of fault-tolerant machines. The case study refers to a five-phase permanent-magnet motor designed for an aircraft flap application. The typical operating conditions of motors designed to operate in fault tolerant environments are considered, such as the opening of one or more phases after the occurrence of a failure. The actual performance of the multiphase motor is compared to that achieved by the superposition of the effects of each phase fed independently, which is the straightforward approach in usual modeling. The results demonstrate that modeling by independent phases leads to negligible errors in almost all the operating conditions
Valutazione dell'esposizione a campi elettromagnetici da impiego di essiccatoi a radiofrequenze (27 MHz) nell'industria laniera
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Sub-Optimal Flux-Weakening Control of Synchronous Reluctance Motors
No full textThis paper deals with the control of the synchronous reluctance motors in the flux-weakening operating range. Given the difficulties of implementing truly optimal control strategies, sub-optimal solutions, which require minimal parametrization and set-up efforts, are proposed and experienced. First, the proposed solutions are presented and discussed, considering the uncoupled, constant-inductances model of the motor in d-q components as an analytical basis. Then, the influence of the flux non-linearities is taken into account, considering a 75 kW motor designed for an electric vehicle as a test case. The deviation in performance compared with the computed maximum torque-to-current and maximum torque-to-voltage optimization criteria are outlined. Finally, experimental results are presented, demonstrating the practical implementation in a micro-controlled drive
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