Computer simulation of lightning flashes to transmission lines

1999 ◽  
Author(s):  
A.J. Phillips
Keyword(s):  
Computer Simulation ◽  
Transmission Lines

ATTRACTOR AND BASIN PORTRAITS OF A DOUBLE SWING POWER SYSTEM

2004 ◽  
Vol 14 (09) ◽  
pp. 3135-3152 ◽  
Author(s):  
YOSHISUKE UEDA ◽  
MAKOTO HIRANO ◽  
HIROFUMI OHTA ◽  
RALPH H. ABRAHAM
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Power System ◽  
Transmission Lines ◽  
General Context ◽  
Deviant Behaviors ◽  
Running Away ◽  
Weakly Coupled ◽  
System Frequency ◽  
Fixed System

In a normal power system, many generators are operating in synchrony. That is, they all have the same speed or frequency, the system frequency. In case some accident occurs, a situation might arise in which one or more generators are running at a different speed, much faster than the system frequency. They are said to be running away or stepping out, or in a state of accelerated stepping out. We have been engaged in a series of studies of this situation, and have found global attractor-basin portraits. In the course of this program, we have observed the phenomenon of decelerated stepping out, in which one or more generators deviate from the system frequency toward lower speeds. These kinds of behavior cannot be explained with the well-known model involving one generator operating on to an infinite bus. Rather, we require a model in which robust subsystems — for example, generator/motor combination, which we call swing pairs — are connected by interconnecting transmission lines. In this more general context, the deviant behaviors we are considering may be regarded as forms of desynchronization of subsystems. We therefore begin this paper with the derivation of a new mathematical model, in which there is no infinite bus nor fixed system frequency. In the simple case of two subsystems (each a swing pair) weakly coupled by an interconnecting transmission line, we develop a system of seven differential equations which include the variation of frequency in a fundamental way. We then go on to study the behavior of this model, using our usual methods of computer simulation to draw the attractor-basin portraits. We have succeeded in finding both accelerated and decelerated stepping out in this new model. In addition, we discovered an unexpected subharmonic swinging of the whole system.

scholarly journals On Some Strategies for Computer Simulation of the Wave Propagation Using Finite Differences I. One–Dimensional FDTD Method

2013 ◽  
Vol 64 (4) ◽  
pp. 213-221
Author(s):  
L̓ubomír Šumichrast
Keyword(s):  
Computer Simulation ◽  
Transmission Lines ◽  
Finite Differences ◽  
Fdtd Method ◽  
Numerical Dispersion ◽  
Electromagnetic Plane Wave ◽  
One Dimensional ◽  
Differential Formulation ◽  
The One ◽  
Wave Phenomena

Some strategies used in the computer simulation of wave phenomena by means of finite differences in time-domain (FDTD) method are reviewed and discussed here. It is shown that the wave equation in its discretized form possesses different properties in comparison with the true differential formulation. In this part the issues of stability and numerical dispersion are thoroughly investigated for the one-dimensional case represented here by waves on transmission lines and transversal electromagnetic plane wave

Coupling Effect of Transmission Lines by HEMP Based on CST

2014 ◽  
Vol 986-987 ◽  
pp. 2064-2067
Author(s):  
Jian Guo Zhang ◽  
Xin Zhang
Keyword(s):  
Computer Simulation ◽  
High Altitude ◽  
Transmission Lines ◽  
Rise Time ◽  
Electromagnetic Pulse ◽  
Coupling Effect ◽  
Electronic Devices ◽  
Model Coupling ◽  
Simulation Technology ◽  
Coupling Current

High-altitude nuclear electromagnetic pulse (HEMP) has a significant effect on electronic devices by cables. This paper makes an analysis of field-wire coupling. With the software of Computer Simulation Technology (CST) constructing the model, coupling current has been acquired. The effect of length, height and impedance on coupling current has been gained. To our surprise, the rise time of HEMP is faster than the time of coupling current. This provides HEMP hardening with the crucial basis.

scholarly journals The implementation of the computer simulation of magnetically insulated transmission lines in post-hole convolute

2010 ◽  
Vol 59 (3) ◽  
pp. 1643
Author(s):  
Liu La-Qun ◽  
Meng Lin ◽  
Deng Jian-Jun ◽  
Song Sheng-Yi ◽  
Zou Wen-Kang ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Transmission Lines ◽  
Post Hole

Characterization of Modulated Structure Through Structure Images and their Computer Simulation

1990 ◽  
Vol 48 (1) ◽  
pp. 70-71
Author(s):  
Kiyomichi Nakai ◽  
Yusuke Isobe ◽  
Chiken Kinoshita ◽  
Kazutoshi Shinohara
Keyword(s):  
Computer Simulation ◽  
High Resolution ◽  
Spherical Aberration ◽  
High Resolution Electron Microscopy ◽  
Basic Mechanism ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Transmitted Beam ◽  
Modulated Structure ◽  
Resolution Electron

Induced spinodal decomposition under electron irradiation in a Ni-Au alloy has been investigated with respect to its basic mechanism and confirmed to be caused by the relaxation of coherent strain associated with modulated structure. Modulation of white-dots on structure images of modulated structure due to high-resolution electron microscopy is reduced with irradiation. In this paper the atom arrangement of the modulated structure is confirmed with computer simulation on the structure images, and the relaxation of the coherent strain is concluded to be due to the reduction of phase-modulation.Structure images of three-dimensional modulated structure along <100> were taken with the JEM-4000EX high-resolution electron microscope at the HVEM Laboratory, Kyushu University. The transmitted beam and four 200 reflections with their satellites from the modulated structure in an fee Ni-30.0at%Au alloy under illumination of 400keV electrons were used for the structure images under a condition of the spherical aberration constant of the objective lens, Cs = 1mm, the divergence of the beam, α = 3 × 10-4 rad, underfocus, Δf ≃ -50nm and specimen thickness, t ≃ 15nm. The CIHRTEM code was used for the simulation of the structure image.

Averting robo-bees: why free-flying robotic bees are a bad idea

2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin
Keyword(s):  
Climate Change ◽  
Computer Simulation ◽  
Food Security ◽  
European Countries ◽  
Plant Interactions ◽  
Plant Insect Interactions ◽  
Native Habitat ◽  
Insect Pollinators ◽  
Insect Interactions

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.

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