Implementation of the sliding-line technique in a MEC model of a linear bistable actuator

Purpose The aim of this study is to investigate the implementation of the sliding-line technique (SLT) in a generic two-dimensional (2D) nonlinear adaptive magnetic equivalent circuit (MEC) model predicting the electromagnetic force evolution of a linear bistable electromagnetic actuator technology. Design/methodology/approach The developed MEC model considers the saturation effect and the auto-adjustability of the spatial discretisation. The connection between static and mobile zones is ensured by an approach known as “air-gap sliding-line technique”, which is widely used for rotary electric motor models. To the best of the author’s knowledge, that is the first time that the SLT is implemented on an electromagnetic structure with linear motion. Findings It was found that, in case of a linear actuator with a relatively small working stroke, the implementation of the SLT could lead to some non-negligible inaccuracies. Originality/value To solve the above-mentioned problem, it was proposed to investigate the implementation of a single SLT vs double SLT. The results of the MEC models were compared with the 2D finite-element analysis (FEA) as well as with the experimental test results. The developed semi-analytical models can be easily adapted to other topologies of linear electromagnetic machines.

Analysis of Electromagnetic Force And Formability of Tube Electromagnetic Bulging Based On Convex Magnetic Field Shaper

In order to solve the problems of non-uniform axial deformation and thinning of wall thickness in traditional tube electromagnetic bulging, a method of tube electromagnetic bulging based on convex magnetic field shaper is proposed in this paper. The electromagnetic-structure coupling model is constructed by using COMSOL software, and the influence of convex magnetic field shaper structure on radial and axial electromagnetic force, axial deformation uniformity and wall thickness reduction is analyzed, and compared with traditional tube electromagnetic bulging. The results show that by using this method, the axial deformation uniformity is increased by 4.2 times, and the relative wall thickness is reduced by 33%. Obviously, this method of tube bulging can effectively overcome the problems existing in traditional tube electromagnetic bulging and promote the wide application of electromagnetic forming technology.

Quantized toroidal dipole eigenvalues in nano-systems

The parity violation in nuclear reactions led to the discovery of the new class of toroidal multipoles. Since then, it was observed that toroidal multipoles are present in the electromagnetic structure of systems at all scales, from elementary particles, to solid state systems and metamaterials. The toroidal dipole T (the lowest order multipole) is the most common. This corresponds to the toroidal dipole operator T ^ in quantum systems, with the projections T ^ i (i = 1, 2, 3) on the coordinate axes. These operators are observables if they are self-adjoint, but, although it is commonly discussed of toroidal dipoles of both, classical and quantum systems, up to now no system has been identified in which the operators are self-adjoint. Therefore, in this paper we use what are called the “natural coordinates” of the T ^ 3 operator to give a general procedure to construct operators that commute with T ^ 3 . Using this method, we introduce the operators p ^ ( k ) , p ^ ( k 1 ) , and p ^ ( k 2 ) , which, together with T ^ 3 and L ^ 3 , form sets of commuting operators: ( p ^ ( k ) , T ^ 3 , L ^ 3 ) and ( p ^ ( k 1 ) , p ^ ( k 2 ) , T ^ 3 ) . All these theoretical considerations open up the possibility to design metamaterials that could exploit the quantization and the general quantum properties of the toroidal dipoles.

Influence of Equivalent Circuit Resistances on Operating Parameters on Three-Phase Induction Motors with Powers up to 50 kW

This work shows the results obtained from studying the influence of equivalent circuit resistances on three-phase induction motors. The stator resistance, rotor resistance, and iron losses resistance affect the different motor operating variables (output power, current, speed, power factor, starting ratios, and maximum torque). These influences have been quantified, paying particular attention to the losses affected and their impact on efficiency. The study carried out does not apply optimization techniques. It evaluates the different influences of the equivalent circuit’s different resistances on its operation by evaluating applicable constructive modifications concerning available motors. The work has been limited to three-phase induction motors up to 50 kW and low voltage, with the nominal powers of the selected motors being 0.25 kW, 1.5 kW, 7.5 kW, 22 kW, and 45 kW. The tools used to carry out the study are analyzing the equivalent circuit and the simulation of the electromagnetic structure using a finite-element program. The variations proposed in each resistance for all the motors studied is not purely theoretical, as it is based on applying feasible constructive modifications, appropriately analyzed and simulated. These modifications are the variation of the conductor diameter in the stator coils, the change of the section of the rotor cage, and the selection of different ferromagnetic steel types.

Incremental Linear Switched Reluctance Actuator

Linear switched reluctance actuators are a focus of study for many applications because of their simple and robust electromagnetic structure, despite their lower thrust force density when compared with linear permanent magnet synchronous motors. This chapter deals with incremental linear actuator have switched reluctance structure. First, the different topologies of linear incremental actuators are mentioned. Furthermore, a special interest is focused on the switched reluctance linear actuator then the operating principal is explained. In addition, an analytical model of the proposed actuator is developed without taking account of the saturation in magnetic circuit. Finally, the control techniques that can be applied to the studied actuator are presented.

“Particle of God” as insulting of the Divine Principle

The author’s research has shown that fundamental magnetic poles (magnetic charges) are real structural components of atoms and substance. It is the magnetic poles, and not the moving electric charges are the direct sources of all magnetic fields and magnetic manifestations in Nature. The main reasons that real magnetic charges were “buried alive” in modern theories are the physics of its confinement in substance which is radically different from the confinement of electrons, as well as the vicious electromagnetic theory (electric magnetism) of Maxwell (1873). The vicious ignoring of real magnetic charges, as well as true anti-electrons in physical science for almost 150 years is responsible for the appearance of such global theoretical delusions as the curvature of 4-dimensional space-time, explaining the nature of gravity, the global expansion of the Universe and the big bang. Annihilation of particles in the pairs particle - antiparticle and many, many others. The author’s experiments have shown that the gravitational field is the vortex electromagnetic field, and all varieties of Physical Mass (FM) are of the electromagnetic atom-figurative structures, which are capable of emitting gravitational field. The masses are, for example, atoms and nucleons. If magnetic charges are removed from the FM composition, then only electric particles will remain in this “place” which themselves, without the participation of magnetic poles, are not able to form either mass or gravitational field. All fundamental electric and magnetic particles are not and cannot become masses, and even “God particles” cannot change anything here. The notion the famous Higgs boson and its main purpose - to give mass to particles is of just a vicious theoretical fiction and a sad result of following erroneous electromagnetic concept of Maxwell. In addition, there is no division of Masses into gravitational and inert ones. The concepts of gravitational and inert mass refer to the same electromagnetic structure, called Mass, but they correspond to different processes of interaction of its gravitational field with other masses (so-called gravitational mass) and the environment (so-called inert mass). As for spinor particles, that is, charged particles, they have the property of inertia, however, this circumstance cannot bind these particles with of a real mass.

100 kW Three-Phase Wireless Charger for EV: Experimental Validation Adopting Opposition Method

This paper presents the experimental validation, using the opposition method, of a high-power three-phase Wireless-Power-Transfer (WPT) system for automotive applications. The system under test consists of three coils with circular sector shape overlapped to minimize the mutual cross-coupling, a three-phase inverter at primary side and a three-phase rectifier at receiver side. In fact thanks to the delta configuration used to connect the coils of the electromagnetic structure, a three-phase Silicon Carbide (SiC) inverter is driving the transmitter side. The resonance tank capacitors are placed outside of the delta configuration reducing in this way their voltage sizing. This WPT system is used as a 100 kW–85 kHz ultrafast battery charger for light delivery vehicle directly supplied by the power grid of tramways. The adopted test-bench for the WPT charger consists of adding circulating boost converter to the system under test to perform the opposition method technique. The experimental results prove the effectiveness of the proposed structure together with the validation of fully exploited simulation analysis. This is demonstrated by transferring 100 kW with more than 94% DC-to-DC efficiency over 50 mm air gap in aligned conditions. Furthermore, testing of Zero-Current and Zero-Voltage commutations are performed to test the performance of SiC technology employed.

Effect of Static Rotor Eccentricity on End Winding Forces and Vibration Wearing

In order to study the vibration wearing regularity and the strength failure point of stator end windings before and after static rotor eccentricity, the three-dimensional electromagnetic forces and the subsequent mechanical responses are studied in this paper. The electromagnetic force, stress, and deformation on the end winding of the QFSN-600-2YHG turbo-generator are calculated by the finite element method (FEM) through an electromagnetic-structure coupling. The radial vibration characteristics of the winding are verified by experiments. It shows that the vibration wearing in the same layer is more serious than that between two neighboring layers. For different layers, the interphase coils endure a larger wearing risk than the innerphase coils. Inside the same phase, the last coil along the rotating direction has the highest risk of insulation wearing. The occurrence of static rotor eccentricity will significantly increase the electromagnetic forces and the vibration amplitudes on some coils. The end-phase coil which is close to the minimum air-gap point is the most dangerous one due to the lasting overstresses and the intensified deformations.