Results 251 to 260 of about 507,617 (286)

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

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

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

Reflection of impulses as a method of determining acoustic impedance

The Journal of the Acoustical Society of America, 1984
An impulse technique has been developed which allows investigation of the reflection of acoustic transients at different angles from an impedance boundary. From measurements of the direct and reflected impulses, the complex surface impedance has been calculated from the ratio of the corresponding Fourier components.
A. J. Cramond, C. G. Don
openaire   +1 more source

Issues Concerning Determination of Impulse Voltage, Current, and Impedance

IEEE Electromagnetic Compatibility Magazine, 2021
The paper deals with satisfying the quasi-stationarity (or quasi-static) condition in studies of impulse quantities. The validity of the definition of voltage, current, and immittance is discussed. Examples are given regarding the electromagnetic compatibility issues when the quasi-stationarity condition is not met, thus the basic electric circuit ...
openaire   +1 more source

An impulse method of measuring normal impedance at oblique incidence

Journal of Sound and Vibration, 1979
Abstract An experimental method of determining the oblique incidence behaviour of sound absorbing materials is given. The method involves the measurement of acoustic impulses at the surface of an absorbing material and comparing the complex frequency components with those of a reference signal recorded remote from the surface.
J.C. Davies, K.A. Mulholland
openaire   +1 more source