Search results for "Linear"
showing 10 items of 7165 documents
Experimental comparison between direct and indirect measurement techniques for the characterization of Linear Induction Motors
1997
Abstract An experimental comparison between direct and indirect measurement techniques for the on-line characterization of Linear Induction Motors (LIMs) is presented. Indirect measurements are based on a mathematical model of the motors. Direct measurements are carried out by means of traditional instruments and a smart sensor, located on the LIM and linked to the controller by the power supply line. Both a synthetic description of the LIM model and the sensor architecture are reported. The experimental results, achieved by applying different feeding strategy, are discussed.
A model of a linear synchronous motor based on distribution theory
2012
The fundamental idea of this paper is to use the distribution theory to analyze linear machines in order to include in the mathematical model both ideal and non ideal features. This paper shows how distribution theory can be used to establish a mathematical model able to describe both the ordinary working condition of a Linear Synchronous Motor (LSM) as well the role of the unavoidable irregularities and non ideal features.
Econo- Environmental Dispatch Solutions for Power Systems Integrated with Renewable Energy Resources
2020
Due to the global initiatives for sustainable energy supply, the electric grids are increasingly integrated with environment-friendly and renewable energy resources. Hence, the power dispatch strategies are to be timely modified by incorporating the environmental aspects of generation along with the economic considerations. In this paper, we propose such an Econo- Environmental dispatch (EED) system for a power grids, which are integrated with renewable energy sources. The EED problem is formulated with two objective functions which aims at minimizing the unit cost of generation as well as minimizing the emissions caused during the power production. For attaining these objectives, cost and …
Linear Waves in Electrical Transmission Lines
1996
Nowadays, linear transmission lines provide vital links in virtually all communications and computer systems, and the parallel-wire line is still widely used today in open-wire form, in coaxial cables and microstrips. The standard twoconductor transmission line is an important familiar system, that is able to support the propagation of transverse electromagnetic modes and is of great interest in many practical situations. We have all often studied this electrical circuit or variation of it in elementary electronics, physics, or mathematics courses (Ramo et al. 1965, Davidson 1978, Badlock and Bridgeman 1981). In fact, the study of linear transmission lines is an old problem: in their simple…
Dynamical Compensation of the Load Torque in a High-Performance Electrical Drive with an Induction Motor
2018
This paper describes a new method for dynamical estimation of load disturbance in induction motors by using Nonlinear Unknown Input Observers (NUIO). This estimation is then used to compensate dynamically the load torque in a Field Oriented Control (FOC) induction motor drive to increase its load-rejection capability. The method has been verified both in simulation and experimentally on a experimental rig.
Optimization of a Sea Wave Energy Harvesting Electromagnetic Device
2008
This paper presents the optimization of a permanent magnet linear generator directly coupled to sea waves. In order to maximize energy extraction, the stochastic features of the energy source is included in the mathematical model of the system in order to satisfactorily tackle the problem. An optimization procedure which includes the stochastic features of the model is presented and a machine built on the basis of the results of this procedure is shown.
Experimental investigation of low-frequency pulsed Lorentz force influence on the motion of Galinstan melt
2016
Abstract The paper presents the results of the numerical and physical experiments, aimed at assessing the influence of pulsed force of electromagnetic field on the melt motion and the fluid velocities. The experiment was performed on the eutectic alloy Galinstan in the cylindrical volume, where an ultrasonic Doppler velocimeter was employed for velocity measurements under conditions of pulsed and steady EM field application. A numerical simulation of the melt flow, forced by the steady EM force, involved a 2D axisymmetric model. The k-e turbulence model was used to obtain the information about the melt velocities. The verification of the numerical model was carried out for the steady case. …
Forward-backward equations for nonlinear propagation in axially invariant optical systems
2004
We present a novel general framework to deal with forward and backward components of the electromagnetic field in axially-invariant nonlinear optical systems, which include those having any type of linear or nonlinear transverse inhomogeneities. With a minimum amount of approximations, we obtain a system of two first-order equations for forward and backward components explicitly showing the nonlinear couplings among them. The modal approach used allows for an effective reduction of the dimensionality of the original problem from 3+1 (three spatial dimensions plus one time dimension) to 1+1 (one spatial dimension plus one frequency dimension). The new equations can be written in a spinor Dir…
Silencing and enhancement of second-harmonic generation in optical gap antennas
2012
International audience; Amplifying local electromagnetic fields by engineering optical interactions between individual constituents of an optical antenna is considered fundamental for efficient nonlinear wavelength conversion in nanometer-scale devices. In contrast to this general statement we show that high field enhancement does not necessarily lead to an optimized nonlinear activity. In particular, we demonstrate that second-harmonic responses generated at strongly interacting optical gap antennas can be significantly suppressed. Numerical simulations are confirming silencing of second-harmonic in these coupled systems despite the existence of local field amplification. We then propose a…
Generalized Einstein-Maxwell field equations in the Palatini formalism
2013
We derive a new set of field equations within the framework of the Palatini formalism.These equations are a natural generalization of the Einstein-Maxwell equations which arise by adding a function $\mathcal{F}(\mathcal{Q})$, with $\mathcal{Q}\equiv F^{\alpha\beta}F_{\alpha\beta}$ to the Palatini Lagrangian $f(R,Q)$.The result we obtain can be viewed as the coupling of gravity with a nonlinear extension of the electromagnetic field.In addition,a new method is introduced to solve the algebraic equation associated to the Ricci tensor.