Search results for "electromagnetic [effect]"
showing 10 items of 555 documents
A General Mathematical Formulation for Winding Layout Arrangement of Electrical Machines
2018
Winding design methods have been a subject of research for many years of the past century. Many methods have been developed, each one characterized by some advantages and drawbacks. Nowadays, the star of slots is the most widespread design tool for electrical machine windings. In this context, this paper presents a simple and effective procedure to determine the distribution of the slot EMFs over the phases and of the winding configuration in all possible typologies of electrical machines equipped with symmetrical windings. The result of this procedure gives a Winding Distribution Table (WDT), which can be used to define coils and coil groups connections and also to simply implement winding…
A General Investigation on the Differential Leakage Factor for Symmetrical and Asymmetrical Multiphase Winding Design
2020
This work provides an investigation based on a fast estimation of the degree of unbalance (D.U.%) and the differential leakage factor (&sigma
Magnetic field controlled FZ single crystal growth of intermetallic compounds
2005
Abstract Intermetallic rare-earth-transition-metal compounds with their coexistence of magnetic ordering and superconductivity are still of great scientific interest. The crystal growth of bulk single crystals is very often unsuccessful due to an unfavorable solid–liquid interface geometry enclosing concave fringes. The aim of the work is the contactless control of heat and material transport during floating-zone single crystal growth of intermetallic compounds. This control is provided by a tailored design of the electromagnetic field and the resulting electromagnetically driven convection. Numerical simulations for the determination of the electromagnetic field configuration induced by th…
Reliable Propagation of Magnetic Domain Walls in Cross Structures for Advanced Multiturn Sensors
2017
[EN] We develop and analyze an advanced concept for a domain-wall-based sensing of rotations. Moving domain walls in n closed loops with n - 1 intersecting convolutions by rotating fields, we are able to sense n rotations. By combining loops with coprime numbers of rotations, we create a sensor system allowing for the total counting of millions of turns of a rotating applied magnetic field. We analyze the operation of the sensor and identify the intersecting cross structures as the critical component for reliable operation. Specifically, depending on the orientation of the applied field angle with the magnetization in the branches of the cross, a domain wall is found to propagate in an unwa…
The transient gravitational-wave sky
2013
Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular of the explosive and transient Universe. Now is the time to challenge our theoretical understanding of short-duration gravitational-wave signatures from cataclysmic events, their connection to more traditional electromagnetic and particle astrophysics, and the data analysis techniques that will make the observations a reality. This paper summarizes the state of the art, future science opportunities, and current challenges in understanding gravitational-wave transients.
Analysis, design, and evaluation of a high frequency inductor to reduce manufacturing cost, and improve the efficiency of a PV inverter
2013
Photovoltaic inverters are the major functional units of the photovoltaic systems. Therefore, efficiency and cost are vitally important in the design, and operation of the PV system. Magnetic components are the bulkiest component and highly affect the efficiency of the galvanically isolated PV inverter and design of such component generally involves a compromise between the reduction of core loss at the expense of increased winding loss or vice versa. The loss characteristics of the magnetic material itself present a fundamental limitation on core loss reduction, implying that the intrinsic reduction of core loss density depends on magnetic material improvements. Hence, the essential tradeo…
Effective-Lagrangian formulation of generalized vector dominance. II
1975
As in a preceding paper we generalize the Lagrangian of Lee and Zumino to include several mutually interacting vector mesons. The treatment is more general in the sense that all possible interactions between the vector mesons, compatible with the field-current proportionality relations, are now discussed. It is moreover demonstrated that also the fields corresponding to the physical vector mesons satisfy a field-current proportionality relation of exactly the same form. Comparison of the different schemes and their implications for the magnetic moments of the vector mesons are discussed.
Refined equivalent single layer formulations and finite elements for smart laminates free vibrations
2014
A family of 2D refined equivalent single layer models for multilayered and functionally graded smart magneto-electro-elastic plates is presented. They are based on variable kinematics and quasi-static behavior for the electromagnetic fields. First, the electromagnetic state of the plate is determined by solving the strong form of the electromagnetic governing equations coupled with the corresponding interface continuity conditions and external boundary conditions. The electromagnetic state is then condensed into the plate kinematics, whose governing equations can be written using the generalized principle of virtual displacements. The procedure identifies an effective elastic plate kinemati…
Zero Ripple Current with Coupled Inductors in Continuous Conduction Mode under PWM Signals
2020
This article presents a generalized analysis to explain current ripple of an $m$ windings coupled inductor with a given coupling factor $k_{ij}$ for each pair of windings and then studies more in detail its use in the continuous conduction mode and with pulsewidth modulated signals. To determine the current ripple, a generalized expression of the equivalent inductance of each winding is calculated, including the influence of voltage unbalance. In the ideal case, the equivalent inductance shows that the current ripple can only become $m$ times smaller than that with uncoupled inductors. But in the unbalanced case, some divergences of the equivalent inductance appear that are responsible for …
Construction, assembly and tests of the ATLAS electromagnetic barrel calorimeter
2006
The construction and assembly of the two half barrels of the ATLAS central electromagnetic calorimeter and their insertion into the barrel cryostat are described. The results of the qualification tests of the calorimeter before installation in the LHC ATLAS pit are given.