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Fundamental Considerations and Impluse Impedance of Grounding Grids
IEEE Transactions on Power Apparatus and Systems, 1981The impulse impedance of a grounding grid must be known for determining its performance while discharging impulse currents to ground if problems concerning lightning protection and transients under ground faults are to be accurately analysed. This paper out-lines the basic concepts required for this study, analyses the equivalent circuit ,21]of a ...
R. Verma, D. Mukhedkar
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Impulse impedance tests on laboratory model ground electrodes
IEE Proceedings - Generation, Transmission and Distribution, 2003Impulse impedance of vertical rods embedded in several soil types was determined by laboratory tests under four temperatures and four soil moisture contents with three different waveshapes of the applied impulse voltage. To avoid errors due to current spikes caused by soil ionisation, it is proposed that the impulse impedance be defined as the ratio ...
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Research on Field Test of Impulse Grounding Impedance for Small Substation
2018 International Conference on Smart Grid and Electrical Automation (ICSGEA), 2018In this paper, application of a portable instrument to obtain impulse grounding impedance (IGI) characteristics for grounding grid of small substation is introduced. The test currents of 8/20 µs, 10/350 µs and 30/80 µs were chosen as the injection signal sources to the grounding grid respectively with simultaneous measurement of the response ...
Si Wen-Rong +5 more
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The impulse grounding impedance computation in HVDC transmission line tower
2013 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC), 2013Electromagnetic field and circuit theory combined is applied to calculate the impulse grounding impedance in HVDC transmission line towers in this paper. The mutual inductance of conductor segments are taken into account. At the same time, the images of the self resistance and mutual inductance are considered for the different medium (soil and air ...
Li Tian-wei, Xiang Yang, Zhao Yu-ming
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A new impulse grounding impedance detection device for transmission tower
2016 International Conference on Condition Monitoring and Diagnosis (CMD), 2016To obtain impulse impedance characteristics for grounding device of transmission tower, a small and portable instrument is developed. It can stable output the 8/20 µs and 10/350 µs standard lightning currents with simultaneous measurement of the response transient voltage waveshapes, which simulates the currents of direct and indirect lightning strikes,
Yue-Qiang Wang +4 more
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Achievements in the Measurement of Tower-footing Impulse Impedance of Transmission Lines
2018 34th International Conference on Lightning Protection (ICLP), 2018This paper presents results obtained from field measurements of tower-footing impulse impedance carried out in real transmission lines. Tests were performed using an impulsive voltage generator, measuring the ground potential rise and the impressed current to determine the impulsive grounding impedance.
Silverio Visacro +2 more
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2023 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (USNC-URSI), 2023
Fernando Albarracin +3 more
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Fernando Albarracin +3 more
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[Diurnal profile of impulse oscillometric impedance in healthy subjects].
Pneumologie (Stuttgart, Germany), 1997Diurnal profiles of impulse oscillometry during 24 hours in 3 hour intervals in sitting and lateral lying position have been studied in 20 healthy female and male probands 10-67 years of age. Approximating the profiles by a sine-cosine-function the amplitude of resistance was found up to 3, that of reactance up to 1 hPa/l/s in single cases, preferably ...
J, Vogel +4 more
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Measurement of respiratory impedance by impulse oscillometry--effects of endotracheal tubes.
Research in experimental medicine. Zeitschrift fur die gesamte experimentelle Medizin einschliesslich experimenteller Chirurgie, 2001Impulse Oscillometry is a new, noninvasive method to measure respiratory impedance, i.e. airway resistance and reactance at different oscillation frequencies. These parameters are potentially useful for the monitoring of respiratory mechanics in the critically ill patent with respiratory dysfunction.
G E, Kuhnle +5 more
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