This paper presents a novel parallel magnetic path hybrid excitation linear eddy current brake. The brake using scheme with the presence of PMs, whose flux lines in primary are oppositely directed respect to by windings, has effect mitigating saturation iron teeth primary. allows be fed more intense currents improving braking force. structure and working principle introduced. analytical model was found equivalent circuit method layer theory approach. design studied finite element method....

The traditional model of the electromagnetic force and torque does not take coil corners into account, which is major cause for motor fluctuation. To reduce fluctuation, a more accurate real-time computation model, considers influence corners, proposed in this paper. Three coordinate systems respectively stator, mover, corner are established. first harmonic magnetic flux density distribution Halbach magnet array taken account model. divided straight segment based on its structure. For...

Low-frequency excitation magnetic field coils are potent tools for studying the effects of fields on cells. However, existing vulnerable to external and difficult generate a high uniform with small size. Thus, this study proposes novel optimization design method combining target (TFM), thickness mirror image method, fruit fly algorithm (FOA) new type bi-planar coil placed in near-zero cell incubator. Based three <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In this paper, a novel 2-DOF permanent magnet planar eddy current damper is proposed, of which the stator made copper plate and mover composed two orthogonal 1-D arrays with double sided structure. The main objective to provide damping forces for dynamic systems like high precision positioning system. Firstly, basic structure operating principle are introduced. Secondly, analytical model established where magnetic flux density distribution obtained by using equivalent charge method image...

Hysteresis is a fundamental characteristic of magnetic materials. The Jiles–Atherton (J-A) hysteresis model, which known for its few parameters and clear physical interpretations, has been widely employed in simulating characteristics. To better analyze compute behavior, this study established state space representation based on the primitive J-A model. First, five equations was through variable substitution simplification. Furthermore, to address singularity problem at zero crossings, local...

In order to solve the problem that relative permeability of permalloy is missing and difficult measure accurately in an extremely weak magnetic field (EWMF, &lt;1 nT), a method EWMF based on Rayleigh model proposed this paper. method, for material was first introduced. Then, test system measuring standard ring specimen set up. Based data model, functional expression applied obtain achieved. Finally, feasibility accuracy are verified by measurement custom large-size (&lt;1 nT) residual...

Abstract The permeability of permalloy at ultra-low-frequency magnetic field is a crucial and fundamental parameter for analyzing the low frequency shielding factor magnetically shielded rooms. However, due to limitations in accuracy existing flux signal measuring system, challenging precisely determine. Therefore, high-precision voltammetry method proposed this paper. First, theory required level induced voltage are derived thoroughly analyzed. Then, acquisition module with ultra-low noise...

In the semiconductor industry, positioning accuracy and acceleration are critical parameters. To improve speed of a motor, this paper proposes moving-coil maglev planar motor with concentric winding structure. The coordinate system has been built for multiple degrees freedom movement system. Lorenz force method applied to solve its electromagnetic model. real-time solving generalized inverse matrix factors can realize decoupling current. When height changes, torque decreases exponentially...

In this study, an inexact stochastic fuzzy programming (ISFP) model is proposed for land-use allocation (LUA) and environmental/ecological planning at a watershed level, where uncertainties associated with parameters, benefit functions, requirements are described as discrete intervals, probabilities sets. model, interval used to support quantitative optimization under uncertainty. Complexities in systems can be systematically reflected, thus applicability of the modeling process highly...

Various uncertainties exist in most urban land-use allocation systems; however, they have not been considered traditional methods. In this study, an interval-probabilistic model is developed based on a hybrid programming method. The can deal with expressed as intervals and probability distributions; moreover, it also help examine the reliability of satisfying (or risk violating) system constraints under uncertainty; only considers economic factors, but involves environmental ecological...

The whole control system is a strong coupling, nonlinear and multivariable because the motion of maglev permanent magnet synchronous planar motor has multi-degrees freedom magnetic field produced by decreases nonlinearly in vertical direction. decoupling linearization levitation force key part for high-speed high-precision control. paper analyzes mathematical model motor. After that, designs controller, which achieves goal linearizing system, using feedback method. simulation result...

A magnetically shielded room (MSR) is the fundamental device in research of extremely weak magnetic fields, and cost-effective improvement its shielding performance very critical to ensure practicality. Thus, this study proposes a method for designing new type magnetic-field compensation coil that clings outer part MSR without interfering with door. In method, irregular coils inner compensating are combined increase uniform area suppress cross-coupling effect. Thereafter, feasibility...

Abstract Investigating the state of cells in zero magnetic or near-zero environments is an important scientific issue. However, standard cell culture incubators can only provide general conditions such as constant temperature, humidity, sterility, and carbon dioxide, cannot for culture. To address this issue, optimization method was proposed paper based on combination particle swarm algorithm (PSO) finite element (FEM), achieving design a shielding box (MSB) with small volume, high factor,...

The maglev linear motor has three degrees of motion freedom, which are respectively realized by the thrust force in x-axis, levitation z-axis and torque around y-axis. Both can be seen as sum forces on windings. resultant independently controlled d-axis current q-axis respectively. Thus, commonly used dq transformation control strategy is suitable for realizing force, either force. However, windings also generate additional because they do not pass mover mass center. To realize system...

The current nonlinear distortion of power converter can cause motion trajectory error and positioning motor, affect the nano accuracy ultra-precision system. resonant pole-based dual buck soft-switching (RPDBSPC) topology does not​ suffer caused by blanking time, support high-frequency operation. It is suitable for field high dynamic high-precision control. In order to realize low current, should possess linear output characteristics, its voltage needs be suppressed. This paper analyzes...

To realize the high-speed and precise control of maglev planar motor, a more accurate real-time electromagnetic model, which considers influence coil corners, is proposed in this paper. Three coordinate systems for stator, mover corner are established. The divided into two segments, straight segment segment, order to obtain complete model. When only take first harmonic flux density distribution Halbach magnet array account, integration method can be carried out towards segments according...

The propulsion force of electrodynamic suspension train is provided by air-cored superconducting linear synchronous motor (AC-SLSM). In this paper, the excitation magnetic field AC-SLSM analyzed in detail. Firstly, basic configuration described. Secondly, detail Biot–Savart law. Finally, effects magnetomotive force, armature current and air gap length on are finite element software.