scholarly journals Global Analysis of Transcriptional Expression in Mice Exposed to Intermediate Frequency Magnetic Fields Utilized for Wireless Power Transfer Systems

2019 ◽  
Vol 16 (10) ◽  
pp. 1851
Author(s):  
Shin Ohtani ◽  
Akira Ushiyama ◽  
Machiko Maeda ◽  
Keiji Wada ◽  
Yukihisa Suzuki ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Flux Density ◽  
Wireless Power Transfer ◽  
Intermediate Frequency ◽  
Whole Body ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Transcriptional Expression ◽  
Wireless Power

Background: Intermediate frequency magnetic fields (IF-MFs) at around 85 kHz are a component of wireless power transfer systems used for charging electrical vehicles. However, limited data exist on the potential health effects of IF-MFs. We performed a comprehensive analysis of transcriptional expression in mice after IF-MF exposure. Materials and Methods: We developed an IF-MF exposure system to generate a high magnetic flux density (25.3 mT). The system can expose the IF-MF for a mouse whole-body without considering thermal effects. After 10 days (1 h/day) of exposure, a comprehensive expression analysis was performed using microarray data from both the brain and liver. Results: No significant differences in transcriptional expression were detected in the 35,240 probe-sets when controlling the false discovery rate (FDR) under a fold change cutoff >1.5. However, several differential expressions were detected without FDR-adjustment, but these were not confirmed by RT-PCR analysis. Conclusions: To our knowledge, this is the first in vivo study to evaluate the biological effects of IF-MF exposure with an intense magnetic flux density 253 times higher than the occupational restriction level defined by the International Commission on Non-Ionizing Radiation Protection guidelines. However, our findings indicate that transcriptional responses in the living body are not affected under these conditions.

scholarly journals Coil Positioning for Wireless Power Transfer System of Automatic Guided Vehicle Based on Magnetic Sensing

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5304
Author(s):  
Ce Liang ◽  
Yanchi Zhang ◽  
Zhonggang Li ◽  
Feng Yuan ◽  
Guang Yang ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Data Fusion ◽  
Flux Density ◽  
Sensor Array ◽  
Wireless Power Transfer ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Wireless Power ◽  
Automatic Guided Vehicle ◽  
Receiving Coil

As an auxiliary function of the wireless power transfer (WPT) system, coil positioning can solve the power and efficiency degradation during power transmission caused by misalignment of the magnetic coupler. In this paper, a Hall sensor array is used to measure the change of magnetic flux density. By comparing the multisensor data fusion results with the preset data obtained from the coil alignment, the real-time accurate positioning of the receiving coil can be realized. Firstly, the positioning model of the receiving coil is built and the variation of magnetic flux density with the coil misalignment is analyzed. Secondly, the arrangement of the Planar 8-direction symmetric sensor array and the positioning algorithm based on data fusion of magnetic flux density variations are proposed. In order to avoid coil positioning misalignment caused by the unstable magnetic field distribution which is actually affected by the change of mutual inductance during automatic guided vehicle (AGV) alignment, the constant current strategy of primary and secondary sides is proposed. Finally, the coil positioning experimental platform is built. The experimental results show that the coil positioning method proposed in this paper has high accuracy, and the positioning error is within 4 cm.

scholarly journals Magnetic Flux Density Measurement Platform for an Inductive Wireless Power Transmitter Coil Design

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 479
Author(s):  
Nataša Prosen ◽  
Miro Milanovič ◽  
Jure Domajnko
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Density Measurement ◽  
Wireless Power Transfer ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Wireless Power ◽  
Search Coil ◽  
Transmitter Coil ◽  
Flux Density Measurement

This paper presents a platform developed for automated magnetic flux density measurement. The platform was designed to be used to measure the magnetic flux density of the transmitter/receiver coil of an inductive wireless power transfer system. The magnetic flux density of a transmitter was measured using a small, 3-axis search coil. The search coil was positioned in the 3D space above the transmitter coil using a 3D positioning mechanism and used to measure the magnetic flux density at a specific point. The data was then sent to a computer application to visualize the magnetic flux density. The measured magnetic field could be used in combination with electromagnetic field solvers to design and optimize transmitter coils for inductive wireless power transfer systems.

scholarly journals Performance of Inductive Coupled Power Transfer Versus the Coil Shape - Investigation using Finite Element Analysis

2018 ◽  
Vol 225 ◽  
pp. 01017 ◽  
Author(s):  
Mohd Fakhizan Romlie ◽  
Kevin Lau ◽  
Mohd Zaifulrizal Zainol ◽  
Mohd Faris Abdullah ◽  
Ramani Kannan
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Coupling Coefficient ◽  
Mutual Inductance ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Element Analysis ◽  
Spiral Coil ◽  
The Impact ◽  
Coil Shape

The objective of this paper is to investigate the impact of the spiral coil shape of inductive coupled power transfer on its performance. The coil shapes evaluated are: circular, square and pentagon spiral shapes. The coils are modelled in Ansoft Maxwell software. Simulations are carried out to determine the mutual inductance, coupling coefficient and magnetic flux density. The performance in term of magnetic flux density, mutual inductance and coupling coefficient of the three coils shapes are compared. Of the three shapes, the pentagon is shown to have the best performance in term of its mutual inductance, coupling coefficient and magnetic flux density.

Study on the transmission characteristics of magnetic resonance wireless power transfer system

2017 ◽  
Vol 9 (9) ◽  
pp. 1799-1807
Author(s):  
Xiufang Wang ◽  
Yu Wang ◽  
Yilang Liang ◽  
Guangcheng Fan ◽  
Xinyi Nie ◽  
...  
Keyword(s):  
High Efficiency ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Parameter Extraction ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Wireless Power ◽  
Element Analysis ◽  
Practical Applications ◽  
Power Transfer Efficiency

Magnetic coupling resonance wireless power transfer technology has attracted worldwide attention in recent years due to its mid-range, non-radiative, and high-efficiency power transfer. However, in regard to its practical applications, there are still some issues that need to be considered and studied with respect to coil design, such as coil structure, and parasitic parameter extraction. This paper investigated the characteristics of magnetic coupling resonance wireless power transfer systems with different coil structures, including circular coils and rectangular coils arranged in parallel. We calculated the magnetic field distributions and mutual inductances by subdividing the receiving coils and computing the magnetic flux density of each subdivision. The proposed analysis was validated by means of the finite element analysis and the experimental results. We investigated the effects of the coil's structure, and topological structures, on the power transfer efficiency. The results demonstrate that using circular coils in parallel is more advantageous than using rectangular coils.

Magnetic phenomena

2004 ◽  
Author(s):  
Robert E. Newnham
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Dipole ◽  
Electric Charge ◽  
Dipole Moments ◽  
Magnetic Flux Density

In this chapter we deal with a number of magnetic properties and their directional dependence: pyromagnetism, magnetic susceptibility, magnetoelectricity, and piezomagnetism. In the course of dealing with these properties, two new ideas are introduced: magnetic symmetry and axial tensors. Moving electric charge generates magnetic fields and magnetization. Macroscopically, an electric current i flowing in a coil of n turns per meter produces a magnetic field H = ni amperes/meter [A/m]. On the atomic scale, magnetization arises from unpaired electron spins and unbalanced electronic orbital motion. The weber [Wb] is the basic unit of magnetic charge m. The force between two magnetic charges m1 and m2 is where r is the separation distance and μ0 (=4π×10−7 H/m) is the permeability of vacuum. In a magnetic field H, magnetic charge experiences a force F = mH [N]. North and south poles (magnetic charges) separated by a distance r create magnetic dipole moments mr [Wb m]. Magnetic dipole moments provide a convenient way of picturing the atomistic origins arising from moving electric charge. Magnetization (I) is the magnetic dipole moment per unit volume and is expressed in units of Wb m/m3 = Wb/m2. The magnetic flux density (B = I + μ0H) is also in Wb/m2 and is analogous to the electric displacement D. All materials respond to magnetic fields, producing a magnetization I = χH, and a magnetic flux density B = μH where χ is the magnetic susceptibility and μ is the magnetic permeability. Both χ and μ are in henries/m (H/m). The permeability μ = χ + μ0 and is analogous to electric permittivity. χ and μ are sometimes expressed as dimensionless quantities (x ̅ and μ ̅ and ) like the dielectric constant, where = x ̅/μ0 and = μ ̅/μ0. Other magnetic properties will be defined later in the chapter. A schematic view of the submicroscopic origins of magnetic phenomena is presented in Fig. 14.1. Most materials are diamagnetic with only a weak magnetic response induced by an applied magnetic field.

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