Results 141 to 150 of about 529,740 (187)

Discussion of Measurement Methods of Impulse Grounding Impedance

2018 34th International Conference on Lightning Protection (ICLP), 2018
The grounding device is very important for lightning protection. However, it is difficult to measure the impulse grounding impedance because the impulse generator is cumbersome and dangerous compared with the device for power frequency test. At the same time it is difficult to generate a lightning current with a suitable waveform due to the inductance ...
Jinjiang He, Zhizhong Li
exaly   +2 more sources

Impulse Impedance Measurements of Lightning Protection Earthings

2019 IEEE PES GTD Grand International Conference and Exposition Asia (GTD Asia), 2019
Lightning protection earthing systems should be tested at currents with time parameters similar to those of lightnings. A method and definition of a measured value of impulse impedance are introduced. The impulse impedance was determined by a quotient of voltage drop on the tested earthing to a value of current in measure circuit. The usefulness of the
T. Horchue, W. Tangtheerajaroonwong, S. Wojtas, M. Woloszyk   +3 more
exaly   +2 more sources

Measurement of Impulse Grounding Impedance in Frequency Domain

2010 International Conference on Intelligent System Design and Engineering Application, 2010
Impulse grounding impedance cannot be described as an absolute index, because it depends on the characteristic of the impulse current waveform, soil structure type and grounding system configuration, etc. This paper presents a test system to measure the impulse grounding impedance directly in time domain, moreover, calculated and defined in frequency ...
Guangning Wu
exaly   +2 more sources

Measurement of respiratory impedance in healthy calves using the impulse oscillation technique—Physiological and methodological aspects

Veterinary Journal, 1998
peer reviewedThe aim of the present study was to investigate methodological and physiological aspects of complex respiratory impedance measurements in calves using the impulse oscillation technique.
P Reinhold, P Lekeux
exaly   +2 more sources

Impulse Impedance and Effective Area of Grounding Grids

IEEE Transactions on Power Delivery, 2021
High values and uneven distribution of the transient ground potential rise (TGPR) at grounding grid conductors in cases of lightning can disrupt the system safety and reliability. To assess the transient performance of grounding grids under lightning currents, a parametric analysis was performed with a computer simulation of 13,978 cases of time-domain
Leonid Grcev, Blagoja Markovski
openaire   +1 more source

Impulse Impedance of Buried Ground Wire

IEEE Transactions on Power Apparatus and Systems, 1980
The performance of ground electrode under impulse currents must be known if problems concerning lightning protection and transients under ground faults are to be accurately analysed. This paper deals with such performance and establishes a simple analytical expression to determine the impulse impedance of a buried ground wire to a short impulse ...
R. Verma, D. Mukhedkar
openaire   +2 more sources

Impulse impedance of rectangular grounding grids

IEEE Transactions on Power Delivery, 1992
In an earlier work B.R. Gupta and B. Thapar (1980) presented the results of investigations and empirical formulae to evaluate the impulse impedance of square grounding grids. In the present work, the authors extend those investigations to the rectangular grounding grids.
B.R. Gupta, V.K. Singh
openaire   +1 more source

The Use of the Impulse Impedance as a Concise Representation of Grounding Electrodes in Lightning Protection Applications

IEEE Transactions on Electromagnetic Compatibility, 2018
Based on measured and simulated results, the features of the first-return-stroke impulse grounding impedance are analyzed to show that, in a vast class of lightning protection applications, using this parameter yields results very similar to those ...
Silverio Visacro
exaly   +1 more source

Online Monitoring of the Cable Insulation State Based on the Impulse Impedance Spectrum

IEEE Transactions on Instrumentation and Measurement
Zhirong Tang, Kai Zhou, Pengfei Meng
exaly   +2 more sources

Characterization of human joint impedance during impulsive motion

Journal of Electromyography and Kinesiology, 1993
The objective of the present work is to make use of the limited existing information on human joint impedance and to supplement and refine it synthetically, by means of simulation. A modular concept was applied to the construction of a joint model. The basic module was an individual revolute joint which was constrained by four resistive elements.
M, Batman, R, Seliktar
openaire   +2 more sources