1,720,995 research outputs found
Comparison between Permanent Magnet Assisted Synchronous Reluctance Motors Considering Electric Vehicle Driving Cycle
No full textPermanent magnet assisted synchronous reluctance motors are becoming a promising solution for electric vehicles, thanks to their high power density, efficiency and increased constant power speed range. The design of the rotor geometry, in terms of amount of PM to be inserted within the machine rotor slots, constitutes a challenging task which has to considered the requirements in terms of speed and torque during a typical electric vehicle driving cycle. This paper presents a comparison among different permanent magnet assisted synchronous reluctance motors for electric vehicles, by also investigating the influence of the number of pole pairs on the main performance indicators. The selected machines are therefore compared in terms of overall efficiency and operating limits, thus leading to some design insights for a given outer envelope
Influence of the Cost Function on the Optimal Design of Magnetic Hysteresis Couplings
No full textThe transmission of a constant torque from zero to synchronous speed with low torque ripple via simple electromechanical devices is an important requirement for a wide range of industrial applications. Hysteresis couplers or clutches can be useful to improve the aforementioned performance indexes, thanks to their unique features. This paper analyzes the influence of the cost functions in the design optimization of magnetic hysteresis couplings. After a brief re-call of a fast method of analysis, several configurations are compared by optimizing the coupler geometry in order to maximize the average torque and minimize the amount of rare-earth material. The obtained results are then deeply analyzed allowing to draw general design guidelines with special emphasis on the influence of the number of poles, cost functions, outer envelope as well as the airgap thickness on the main performance indexes
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
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