An introduction to the analysis of short-circuit earth return current, rise of earth potential and electrical interference

2008 ◽  
pp. 550-604 ◽  
Author(s):  
Nasser D. Tleis
Keyword(s):  
Short Circuit ◽  
Return Current ◽  
Current Rise ◽  
Electrical Interference ◽  
Earth Potential

scholarly journals Specifics of automatic switches commutation testing

2019 ◽  
Vol 124 ◽  
pp. 03016
Author(s):  
E. G. Egorov ◽  
N. Yu. Luiya ◽  
E. V. Mikhailova ◽  
V. N. Pichugin ◽  
R. V. Fedorov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Normal Mode ◽  
Short Circuit ◽  
Test Preparation ◽  
Return Current ◽  
Wave Parameters ◽  
Amplitude Coefficient ◽  
Test Circuit ◽  
Three Phase ◽  
Contact Arc

We demonstrate that the most efficient way to extinguish the short-circuit arc is extinguishing inside the camera with an arc extinguishing grid, which splits it into several smaller arcs. The active resistivity of these partial arcs decreases the amplitude of the current of the short-circuit arc, decreases the angle φ between current and voltage, which decreases the amplitude of the return current and enhances the condition for the arc extinguishing. We analyze the process of arc extinguishing in the three-phase circuit. We would like to note that during the extinguishing of the arc in the first extinguishing pole resistance of electric arcs in two other poles deforms the voltage triangle decreasing the coefficients of the scheme from 1.5 to 1.3 according to the experimental data. This allows to decrease the difficulty of the tests for maximum commutation capability. Simultaneously, we consider the necessity of the selection and regulation of the wave parameters (amplitude coefficient and normal mode) of the test circuit according to the standard for test preparation. Taking into account the decrease of the coefficient of the scheme and the real wave parameters will allow to objectively estimate commutation capability and to optimize the parameters pf the contact arc extinguishing system of an automated switch.

Structural Imperfections in thin Oxide Films Formed on Some Fe- and Ni-Base Alloys

1970 ◽  
Vol 28 ◽  
pp. 510-511
Author(s):  
L. P. Lemaire ◽  
D. E. Fornwalt ◽  
F. S. Pettit ◽  
B. H. Kear
Keyword(s):  
Oxide Scale ◽  
Oxidation Process ◽  
Short Circuit ◽  
Protective Oxide ◽  
Protective Oxide Scale ◽  
Thin Oxide Films ◽  
Diffusion Paths ◽  
Oxidation Resistant ◽  
Structural Imperfections ◽  
Short Circuit Diffusion

Oxidation resistant alloys depend on the formation of a continuous layer of protective oxide scale during the oxidation process. The initial stages of oxidation of multi-component alloys can be quite complex, since numerous metal oxides can be formed. For oxidation resistance, the composition is adjusted so that selective oxidation occurs of that element whose oxide affords the most protection. Ideally, the protective oxide scale should be i) structurally perfect, so as to avoid short-circuit diffusion paths, and ii) strongly adherent to the alloy substrate, which minimizes spalling in response to thermal cycling. Small concentrations (∼ 0.1%) of certain reactive elements, such as yttrium, markedly improve the adherence of oxide scales in many alloy systems.

Short Circuit Currents of Normal and Crohn's Diseased Human Colonic Mucosa

Endoscopy ◽  
2006 ◽  
Vol 38 (11) ◽  
Author(s):  
A Patel ◽  
DL Bovell ◽  
AD Corbett ◽  
RJ Holdsworth
Keyword(s):  
Colonic Mucosa ◽  
Short Circuit ◽  
Short Circuit Currents

Determination of parameters of short circuit of power transformer by means of mathematical modeling

2017 ◽  
Vol 26 (102) ◽  
pp. 110-119
Author(s):  
D. S. Yarymbash, ◽  
◽  
S. T. Yarymbash, ◽  
T. E. Divchuk, ◽  
D. A. Litvinov
Keyword(s):  
Mathematical Modeling ◽  
Power Transformer ◽  
Short Circuit ◽  
Determination Of Parameters

Estimation Methods of Short Circuit Current using Normal PMU Measurements and Field Testing

2013 ◽  
Vol 133 (1) ◽  
pp. 37-44
Author(s):  
Suresh Chand Verma ◽  
Yoshiki Nakachi ◽  
Yoshihiko Wazawa ◽  
Yoko Kosaka ◽  
Takenori Kobayashi ◽  
...  
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Field Testing ◽  
Estimation Methods
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