Magnetic compensation coils are often used to improve the effectiveness of a magnetically shielded room (MSR), but distortion field is caused by shielding layer consisting high-permeability material, which leads reduction in capacity. To solve this problem, new method presented article based on target-field method, an image and particle swarm optimization. By way, magnetic system composed biplanar designed fabricated compensate background for wearable magnetoencephalography device inside...

The utilization of nanocrystalline magnetic shielding can provide a low-noise weak environment for various ultra-high sensitivity measurements. Their interlayer insulation properties effectively impede eddy currents, thereby ameliorating current losses and diminishing noise within the structure. However, nanocrystal's thin-layered structure stacking process greatly impact its effective permeability conductivity. Hence, this article presents quantitative evaluation research methodology...

The uniform field and gradient coils can be utilized for nulling background inside magnetic shielding room (MSR), but the desired produced by is inevitably distorted due to coupling effect of material. To overcome this problem, an improved method proposed based on image target (TFM). Directed method, a series bi-planar are designed produce fields gradients active compensation in MSR. Then, their finite element models practical experiment established verify effectiveness. Compared with...

A novel method to design highly uniform axial coils inside a closed magnetically shielded cylinder (MSC) is presented. The proposed has two major advantages over existing methods. First, based on the coupling model of coil and MSC with finite permeability thickness, image target-field (TFM) are introduced provide flexible for MSC. Second, backpropagation neural network (BPNN) particle swarm optimization (PSO) algorithm used predict optimize parameters, thus reducing magnetic field deviation...

Abstract Magnetic shielded cylinder (MSC) is crucial in various applications, especially the realm of medical weak magnetic signal measurement. However, designing a small volume, low noise MSC multi-objective optimization problem, with objectives conflict each other. To address complexity arising from numerous variables optimal design volume and low-noise, this paper proposes an method based on non-dominated sorting genetic algorithm II (NSGA-II) to realize high shielding factor, low-noise....

To achieve the nearly zero-field environment, demagnetization is an indispensable step for magnetic shields composed of high-permeability material, which adjusts magnetization material to establish equilibrium with environmental field and improve shielding performance. The ideal can make on anhysteretic curve have a higher permeability than initial curve. However, inappropriate parameters degaussing cause state deviate from Therefore, this article proposes new assessment criterion analyze...

Biomagnetic field measurements necessitate magnetic shields of high performance, particularly for quasi-static and low-frequency fields. These largely rely on the properties shielding material. Magnetic shaking can enhance material's permeability by reducing hysteresis loss, though this method introduces interference into device, complicating environment. In study, an attenuation coefficient is introduced Jiles–Atherton model to quantify suppression effect based under To improve performance...

Temperature rise caused by losses is a key issue for high-speed machine. This paper deals with loss calculation and thermal analysis of magnetically suspended PM machine (MSPMM) an actual power 33 kW rotation speed 55 332 r/min. The temperature distribution based on the finite element method obtained accounting various losses, which consist air friction copper iron radial magnetic bearing, combined radial/axial permanent magnet (PMM). A back-to-back test setup two MSPMM fabricated verifying...

The stable control of the active magnetic bearing rotor (AMB-rotor) system is key technology for a magnetically suspended moment gyroscope, which used in spacecraft attitude system. nutation and precession instability caused by strong gyroscopic effects principal issue AMB-rotor In order to solve problem, this article, state-space model radial four-degree-of-freedom established, term varying with speed regarded as bounded perturbation. regional pole assignment method an uncertain design...

Generally, a permalloy sheet is applied as the major shielding material for weakening environmental magnetic field interference in of high-precision measurement. The demagnetization determines its performance; therefore, an enhanced method measuring properties under degaussing excitation proposed this paper. apparatus and feedback control system are designed regulating B curve desired amplitude waveform. Furthermore, applying corresponding measurement approach such conditions investigated....

The three degree‐of‐freedom (3‐DOF) hybrid magnetic bearing (HMB) sets radial, axial at one entirety, which can effectively save the installation space. Here, a 3‐DOF HMB is designed, optimised, and tested for 30 kW 60,000 r/min high‐speed motor system. radial capacity analysed by equivalent circuit method dimensional finite element model (FEM) of initial established. Then, capacity, current‐stiffness, displacement‐stiffness are selected as optimised design target using chaos particle swarm...

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"...

Abstract The demand for spatial nonlinear magnetic fields (SNMF) spans diverse domains, encompassing medical applications like drug transportation and aerospace such as attitude control. Existing designs of field coils predominantly focus on uniform gradient the complexity distribution often leads to intricate solution processes. This paper presents a novel approach coil design, addressing challenge SNMF by reconstructing characteristic matrix within traditional target method (TFM). To solve...

The radiant ceiling system is considered to be a promising technology capable of meeting sustainable cooling requirements. Correct evaluation the heat transfer process important for its design and practical applications. This article reports research on developing new simplified correlations total coefficient flux density panels. are proposed based experimental results. experiments conducted in climate chamber under different combinations indoor operative temperature supply water...

Temperature rise subjected to the copper losses and iron is an important issue for a magnetically suspended turbomolecular pump (MSTMP). In this study, loss estimation, thermal analysis, temperature measurement of large‐scale MSTMP are investigated. The core two radial magnetic bearings, thrust bearing, brushless direct current motor (BLDCM) predicted by analytical models. Based on values, heat generation rates in different parts calculated, then field prototype analysed 3D finite‐element...