Results 131 to 140 of about 1,321 (185)

Evaluation of breakdown characteristics of oil-immersed transformers under non-standard lightning impulse waveforms - method for converting non-standard lightning impulse waveforms into standard lightning impulse waveforms

IEEE Transactions on Dielectrics and Electrical Insulation, 2008
To lower the insulation specifications (specifically, the lightning impulse withstand voltage) of oil-immersed transformers and thus reduce equipment cost while maintaining high insulation reliability, it is required to identify the insulation characteristics under non-standard lightning impulse waveforms that are associated with actual surge waveforms
Jun Takami
exaly   +2 more sources

High-Accuracy Comparison of Lightning and Switching Impulse Calibrators

IEEE Transactions on Instrumentation and Measurement, 2007
This paper summarizes the results of a comparison on two calculable impulse voltage calibrators and one commercial calibrator between Helsinki University of Technology, Finland (MIKES-TKK), Nippon Institute of Technology, Japan (NIT), and Physikalisch-Technische Bundesanstalt, Germany (PTB).
Wakimoto, Takayuki, Hällström, Jari K., Chekurov, Y., Ishii, M., Lucas, Wolfgang, Piiroinen, J., Shimizu, Hiroyuki   +7 more
openaire   +1 more source

Robust evaluation procedure for lightning impulses

Proceedings of the 7th International Conference on Properties and Applications of Dielectric Materials (Cat. No.03CH37417), 2004
The existing recommendation for high voltage tests, IEC Publication 60060, is ambiguous in the evaluation of the impulse test voltage, when oscillations or overshoot are superimposed on the peak of the smooth, double exponential waveshape. Particularly impulse tests on transformers may be critical due to the high stress on the insulation during the ...
K. Hackemack, E. Gockenbach
openaire   +1 more source

Lightning Impulse Tests on Tower Models

IEEE Transactions on Power Apparatus and Systems, 1984
Lightning impulse tests on long insulator strings have been carried out in an attempt to determine the impulse strength of tower insulation in the EHV-UHV ranges.
J. R. Fonseca, V. H. G. Andrade, P. C. V. Esmeraldo, L. E. N. Dias   +3 more
openaire   +1 more source

Lightning Impulse Voltage Evaluation

2017
This research studied and developed software for lightning impulse voltage parameters evaluation. Full lightning impulse voltage of 9 cases in TDG program had been used as references for software tested. This software created 2 types of voltage waveform which are mean curve and approximate real curve. Kalman Filter had been used for mean curve.
Nopphadon Khodpun, Krisada Vilailak
openaire   +1 more source

Virtual Instrument for Lightning Impulse Tests

IEEE Transactions on Power Delivery, 2007
We propose an objective formulation of the impulse analysis problem from a signal analysis viewpoint. The winding response is quintessentially that of a deterministic network to a finite energy signal, with breakdown and partial discharge being inherently nonlinear events.
A. Palani, V. Jayashankar
openaire   +1 more source

A new proposal for the evaluation of lightning impulses

Proceedings of the 6th International Conference on Properties and Applications of Dielectric Materials (Cat. No.00CH36347), 2002
In this contribution a new method for the characterization of lightning impulses superimposed with oscillations and overshoot is presented. The proposal bases on experimental investigation on lightning impulse tests performed with different dielectric media in the framework of an European project.
K. Hackemack, P. Werle, E. Gockenbach, H. Borsi   +3 more
openaire   +1 more source

Electrical parameters of water at lightning impulse

Proceedings of the 2014 15th International Scientific Conference on Electric Power Engineering (EPE), 2014
This paper deals with the description of the behavior of water at lightning impulses. The electric potential distribution in water at lightning impulses is simulated for the calculation of the safe distance. There are not hazardous conditions to human body at distances greater than the safe distance.
Michal Krbal, Petr Baxant, Jan Skoda, Stanislav Sumec   +3 more
openaire   +1 more source

Modern impulse generators for testing lightning arresters

Electrical Engineering, 1942
1. Thorough testing of lightning arresters requires a wide variety of impulse-current waves. 2. The strictly mathematical calculation of circuit constants to produce such waves is limited to the few cases where the circuit resistance is constant. 3. Valve-type lightning arresters have a resistance that is intentionally a function of voltage or current ...
openaire   +2 more sources

Effects of Soil Ionization and Lightning Impulse Corona on Lightning Current Strike

2020
With the new structural changes of power system that has emerged in recent years, which makes manufacturing units transmit more and more electrical power from the transmission lines, it is expected that a wider voltage collapse in the power systems happens.
Amouzad Mahdiraji, Ebadollah, Yousefi Talouki, Amir   +1 more
openaire   +1 more source