scholarly journals Design and Experiments of a Galloping-Based Wind Energy Harvester Using Quadruple Halbach Arrays

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6094
Author(s):  
Hai Dang Le ◽  
Soon-Duck Kwon
Keyword(s):  
High Performance ◽  
Low Frequency ◽  
Electrical Energy ◽  
Load Resistance ◽  
Field Analysis ◽  
Magnetic Flux Density ◽  
Original Design ◽  
Halbach Array ◽  
Magnetic Field Analysis ◽  
Halbach Arrays

This study aims to develop a device for harvesting electrical energy from low-speed natural wind. Four linear Halbach arrays are adopted to design a high-performance galloping harvester with the advantage of high durability and efficiency at low-frequency vibrations. The results of magnetic field analysis reveal that there are optimal sizes of the main and transit magnets of the Halbach arrays and coil to obtain the maximum magnetic flux density normal to the coil. The experimental and simulation results show that the electrical external load resistance significantly affects the vibration amplitude and the galloping onset velocity of the harvester. The results also reveal that the performance of the original design using the quadruple Halbach array was lower than that of the existing harvester because of the heavy magnet mass embedded in the tip prism. The modified design, reducing mass, improved the performance by four times compared to the original design.

Characteristic and Magnetic Field Analysis of a Novel Ironless Halbach Permanent Magnet Linear Synchronous Motor

2013 ◽  
Vol 416-417 ◽  
pp. 149-155
Author(s):  
Lu Zhang ◽  
Bao Quan Kou ◽  
Bin Chao Zhao ◽  
Feng Xing
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Synchronous Motor ◽  
Field Analysis ◽  
Magnetic Flux Density ◽  
Linear Synchronous Motor ◽  
Halbach Array ◽  
Magnetic Field Analysis ◽  
Magnetization Intensity ◽  
Flux Density Distribution

This paper proposes an ironless permanent magnet linear synchronous motor (ILPMLSM) with a novel Halbach array. The magnetic flux density distribution of the Halbach array is solved analytically by using the equivalent magnetization intensity method. The expressions of no-load back-EMF and electromagnetic thrust are obtained. All of the results are verified by finite element method and they are coincide very well.

2-D Magnetic Field Analysis of Air Cylinder with MR Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 2706-2709
Author(s):  
Dan Jiang ◽  
Ping Yang ◽  
Kun Jiang
Keyword(s):  
Magnetic Field ◽  
Field Analysis ◽  
Magnetic Flux Density ◽  
Piston Motion ◽  
Element Analysis ◽  
Pneumatic Control ◽  
Magnetoresistive Sensor ◽  
Magnetic Field Analysis ◽  
Working Principle ◽  
The Magnetic Field

As a type of solid state switch, MR (magnetoresistive) sensor detects the air cylinder piston’s position in pneumatic control system. The construction and working principle of the air cylinder with MR sensor are introduced. Using 2-D magnetic field finite element analysis (FEA) method, the magnetic field distribution of air cylinder with piston motion is analyzed. Simulation results are given. The magnetic flux density characteristics are compared between piston wear or not.

scholarly journals Comment on "Ultra Low Frequency (ULF) European multi station magnetic field analysis before and during the 2009 earthquake at L'Aquila regarding regional geotechnical information" by Prattes et al. (2011)

2012 ◽  
Vol 12 (5) ◽  
pp. 1717-1719 ◽  
Author(s):  
F. Masci
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Activity ◽  
Low Frequency ◽  
Field Analysis ◽  
L’Aquila Earthquake ◽  
Magnetic Field Analysis ◽  
Magnetic Signatures ◽  
Geotechnical Information

Abstract. Prattes et al. (2011) report ULF magnetic anomalous signals claiming them to be possibly precursor of the 6 April 2009 MW = 6.3 L'Aquila earthquake. This comment casts doubts on the possibility that the observed magnetic signatures could have a seismogenic origin by showing that these pre-earthquake signals are actually part of normal global geomagnetic activity.

scholarly journals Structural Parameter Optimization of a Tubular Permanent-Magnet Linear Machine for Regenerative Suspension

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dongsheng Lu ◽  
Hailong Zhang ◽  
Jian Liu ◽  
Enrong Wang
Keyword(s):  
Permanent Magnet ◽  
Analytical Model ◽  
Structural Parameters ◽  
Field Analysis ◽  
Structural Parameter ◽  
Element Analysis ◽  
Modified Particle Swarm Optimization ◽  
Halbach Array ◽  
Magnetic Field Analysis ◽  
Permanent Magnet Linear Motor

The regenerative suspension can effectively recover the vibration potential energy of the vehicle suspension, thus has broad prospects in application. In this paper, a tubular permanent-magnet linear motor (TPMLM) with the Halbach array magnetic pole is analyzed. The magnetic field analysis method of the excitation source separation is proposed, and then, the transient analytical model of output electromagnetic force and the external circuit characteristic under displacement excitation is established. A modified particle swarm optimization algorithm is further adopted to optimize the structural parameters of TPMLM. By comparing with the finite element analysis, the correctness of the proposed analytical model and the optimization are verified. This work lays the theoretical foundation for extensive application of the regenerative suspension.

scholarly journals Ultra Low Frequency (ULF) European multi station magnetic field analysis before and during the 2009 earthquake at L'Aquila regarding regional geotechnical information

2011 ◽  
Vol 11 (7) ◽  
pp. 1959-1968 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Field Measurements ◽  
Field Analysis ◽  
Electromagnetic Noise ◽  
European Collaboration ◽  
Magnetic Field Analysis ◽  
Time Period ◽  
Power Spectral ◽  
Geotechnical Information

Abstract. This work presents ground based Ultra Low Frequency (ULF) magnetic field measurements in the frequency range from 10–15 mHz from 1 January 2008 to 14 April 2009. In this time period a strong earthquake series hit the Italian Abruzzo region around L'Aquila with the main stroke of magnitude M = 6.3 on 6 April 2009. In the frame of the South European Geomagnetic Array (SEGMA), a European collaboration runs ULF fluxgate instruments providing continuously magnetic field data recorded in mid- and south Europe. The main scientific objective is the investigation of signal variations due to seismic activity and the discrimination between other natural and human influences. The SEGMA station closest to the L'Aquila earthquake epicenter is L'Aquila observatory located in the epicenter region. For the scientific analysis we extract the nighttime period from 22:00–02:00 UT and determine the power spectral density (PSD) of the horizontal (H) and vertical (Z) magnetic field components and the standardized polarization ratio (Z) over (H). To discriminate local emissions from global geomagnetic effects, data from three SEGMA stations in distances up to 630 km from the epicenter region are analyzed and further compared to the independent global geomagnetic ∑ Kp index. Apart from indirect ionospheric effects, electromagnetic noise could be originated in the lithosphere due to tectonic mechanisms in the earthquake focus. To estimate the amplitude of assumed lithospheric electromagnetic noise emissions causing anomalies in the PSD of the (Z) component, we consider magnetotelluric calculations of the electric crust conductivity in the L'Aquila region. Results found at L'Aquila observatory are interpreted with respect to the lithosphere electrical conductivity in the local observatory region, the ∑ Kp index, and further in a multi station analysis. Possible seismic related ULF anomalies occur ~2 weeks before the main stroke.

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