Analysis and Optimization of Magnetic Energy Converters for Wireless Sensors in Substation

2012 ◽  
Vol 229-231 ◽  
pp. 1068-1071
Author(s):  
Yan Cheng ◽  
Jin Xin Huang ◽  
Chun Hui Yu ◽  
Li Zhang
Keyword(s):  
Wireless Sensors ◽  
Solution Method ◽  
Magnetic Energy ◽  
Structural Parameters ◽  
Wireless Sensor ◽  
Field Energy ◽  
Energy Scavenging ◽  
Energy Converter ◽  
Principal Element ◽  
Magnetic Field Energy

With the development of wireless sensor networks, energy supplying problem become critical. However, energy scavenging technology provides an efficient solution method, and it is the principal element for wireless sensors to facilitate on-site self-powering. A magnetic energy converter which can convert magnetic field energy to power is proposed when there is sufficient magnetic energy in substations. By modeling this converter, the inductive factor was defined to present energy harvesting capability and optimization was realized in terms of framework material, structural parameters and turns of coils. The research results present theoretical basis for optimal design of the energy scavenging devices.

scholarly journals Magnetic dynamo action in two-dimensional turbulent magneto-hydrodynamics

1977 ◽  
Vol 17 (2) ◽  
pp. 317-335 ◽  
Author(s):  
David Fyfe ◽  
Glenn Joyce ◽  
David Montgomery
Keyword(s):  
Initial Conditions ◽  
Magnetic Energy ◽  
Field Energy ◽  
Magnetic Excitation ◽  
External Forcing ◽  
Two Dimensional ◽  
Dynamo Action ◽  
Magnetohydrodynamic Turbulence ◽  
Long Wavelength ◽  
Magnetic Field Energy

Two-dimensional magnetohydrodynamic turbulence is explored by means of numerical simulation. Previous analytical theory, based on non-dissipative constants of the motion in a truncated Fourier representation, is verified by following the evolution of highly non-equilibrium initial conditions numerically. Dynamo action (conversion of a significant fraction of turbulent kinetic energy into long-wavelength magnetic field energy) is observed. It is conjectured that in the presence of dissipation and external forcing; a dual cascade will be observed for zero-helicity situations. Energy will cascade to higher wavenumbers simultaneously with a cascade of mean square vector potential to lower wavenumbers, leading to an omni-directional magnetic energy spectrum which varies as k-⅓ at lower wavenumbers, simultaneously with a build-up of magnetic excitation at the lowest wavenumber of the system. Equipartition of kinetic and magnetic energies is expected at the highest wavenumbers in the system.

scholarly journals Fast magnetic energy dissipation in relativistic plasma induced by high order laser modes

2016 ◽  
Vol 4 ◽  
Author(s):  
Y. J. Gu ◽  
Q. Yu ◽  
O. Klimo ◽  
T. Zh. Esirkepov ◽  
S. V. Bulanov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Energy ◽  
Collisionless Plasma ◽  
High Energy ◽  
Field Energy ◽  
Displacement Current ◽  
Particle In Cell ◽  
Magnetic Field Energy ◽  
High Energy Electrons

Fast magnetic field annihilation in a collisionless plasma is induced by using TEM(1,0) laser pulse. The magnetic quadrupole structure formation, expansion and annihilation stages are demonstrated with 2.5-dimensional particle-in-cell simulations. The magnetic field energy is converted to the electric field and accelerate the particles inside the annihilation plane. A bunch of high energy electrons moving backwards is detected in the current sheet. The strong displacement current is the dominant contribution which induces the longitudinal inductive electric field.

scholarly journals Slowing the spins of stellar cores

2019 ◽  
Vol 485 (3) ◽  
pp. 3661-3680 ◽  
Author(s):  
Jim Fuller ◽  
Anthony L Piro ◽  
Adam S Jermyn
Keyword(s):  
Magnetic Field ◽  
Magnetic Energy ◽  
Compact Objects ◽  
Field Energy ◽  
Red Giants ◽  
Turbulent Dissipation ◽  
Rotation Rates ◽  
Magnetic Field Energy ◽  
Rotational Evolution ◽  
Red Giant

ABSTRACT The angular momentum (AM) evolution of stellar interiors, along with the resulting rotation rates of stellar remnants, remains poorly understood. Asteroseismic measurements of red giant stars reveal that their cores rotate much faster than their surfaces, but much slower than theoretically predicted, indicating an unidentified source of AM transport operates in their radiative cores. Motivated by this, we investigate the magnetic Tayler instability and argue that it saturates when turbulent dissipation of the perturbed magnetic field energy is equal to magnetic energy generation via winding. This leads to larger magnetic field amplitudes, more efficient AM transport, and smaller shears than predicted by the classic Tayler–Spruit dynamo. We provide prescriptions for the effective AM diffusivity and incorporate them into numerical stellar models, finding they largely reproduce (1) the nearly rigid rotation of the Sun and main sequence stars, (2) the core rotation rates of low-mass red giants during hydrogen shell and helium burning, and (3) the rotation rates of white dwarfs. We discuss implications for stellar rotational evolution, internal rotation profiles, rotational mixing, and the spins of compact objects.

A Non-Resonant Magnetoelectric Energy Converter for Scavenging Magnetic Field Energy From Two-Wire Power Cords

2016 ◽  
Vol 52 (7) ◽  
pp. 1-4
Author(s):  
Wei He ◽  
Chiwen Qu ◽  
Jitao Zhang ◽  
Jie Wu ◽  
Jiancai Peng
Keyword(s):  
Magnetic Field ◽  
Field Energy ◽  
Energy Converter ◽  
Magnetic Field Energy

scholarly journals Estimating the magnetic energy inside traveling compression regions

2009 ◽  
Vol 27 (5) ◽  
pp. 1969-1978 ◽  
Author(s):  
S. A. Kiehas ◽  
V. S. Semenov ◽  
H. K. Biernat ◽  
V. V. Ivanova ◽  
R. Nakamura ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Kinetic Energy ◽  
Theoretical Result ◽  
Magnetic Energy ◽  
Field Energy ◽  
Plasma Energy ◽  
Magnetic Field Energy ◽  
The Magnetic Field

Abstract. We investigate a series of six TCRs (traveling compression regions), appearing in the course of a small substorm on 19 September 2001. Except for two of these TCRs, all Cluster spacecraft were located in the lobe and detected the typical signatures of TCRs, i.e., compressions in |B| and bipolar Bz variations. We use these perturbations in Bz for calculations on the magnetic energy inside the TCR and compare the amount of magnetic field energy with the kinetic energy inside the underlying plasma bulge. According to results obtained from theory, the amount of magnetic energy inside TCRs is about two times higher than the kinetic plasma energy inside the accompanied plasma bulge. We verify this theoretical result by first investigations of the magnetic field energy inside TCRs. The calculations lead to a magnetic energy in the order of 1010 Joule per RE for each of the TCRs.

scholarly journals Magnetic Fields in Accretion Disks

1999 ◽  
Vol 16 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Marthijn de Kool ◽  
Geoffrey V. Bicknell ◽  
Zdenka Kuncic
Keyword(s):  
Magnetic Fields ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Magnetic Energy ◽  
Significant Part ◽  
Field Energy ◽  
Dynamo Action ◽  
Magnetic Field Energy ◽  
Non Local ◽  
Energy And Momentum

AbstractThis paper summarises our work on the role of magnetic fields in accretion disks presented in two papers elsewhere. In the first part (a summary of part of Kuncic & Bicknell 1999), we present a formal development of the equations governing the structure of an accretion disk containing magnetohydrodynamic turbulence. The importance of the different terms in the energy and momentum equations is discussed, and a parametrisation of the unresolved processes is suggested that could be used to make further progress. We briefly explore whether an MHD accretion disk can transport a significant part of the gravitational power into a corona by buoyancy. In the second part, we present some exploratory calculations of the vertical structure of accretion disks, in which non-local dissipation of energy due to the buoyant transport of magnetic field energy is taken into account. It is argued that the efficiency of buoyant magnetic transport depends very strongly on the size of the coherent magnetic regions. If the size of the buoyant cells is not very close to the disk thickness, magnetic energy generated by dynamo action inside the disk will be dissipated locally, and will not be available to transport a significant part of the accretion luminosity into a corona.

scholarly journals Sensor System: A Survey of Sensor Type, Ad Hoc Network Topology and Energy Harvesting Techniques

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 219
Author(s):  
Phuoc Duc Nguyen ◽  
Lok-won Kim
Keyword(s):  
Energy Harvesting ◽  
Large Scale ◽  
Ad Hoc ◽  
Sensor Nodes ◽  
Sensor System ◽  
Wireless Sensor ◽  
The Internet ◽  
Original Research ◽  
Energy Scavenging ◽  
Term Operation

People nowadays are entering an era of rapid evolution due to the generation of massive amounts of data. Such information is produced with an enormous contribution from the use of billions of sensing devices equipped with in situ signal processing and communication capabilities which form wireless sensor networks (WSNs). As the number of small devices connected to the Internet is higher than 50 billion, the Internet of Things (IoT) devices focus on sensing accuracy, communication efficiency, and low power consumption because IoT device deployment is mainly for correct information acquisition, remote node accessing, and longer-term operation with lower battery changing requirements. Thus, recently, there have been rich activities for original research in these domains. Various sensors used by processing devices can be heterogeneous or homogeneous. Since the devices are primarily expected to operate independently in an autonomous manner, the abilities of connection, communication, and ambient energy scavenging play significant roles, especially in a large-scale deployment. This paper classifies wireless sensor nodes into two major categories based the types of the sensor array (heterogeneous/homogeneous). It also emphasizes on the utilization of ad hoc networking and energy harvesting mechanisms as a fundamental cornerstone to building a self-governing, sustainable, and perpetually-operated sensor system. We review systems representative of each category and depict trends in system development.

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