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  • 1.
    Akyuz, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Berg, M
    Larsson, A
    Thottappillil, R
    Calculation of the electrostatic force acting on dielectric bodies1999Ingår i: 11th International Symposium of Hight Voltage Engineering (ISH), London, UK, August 23-27, 1999Konferensbidrag (Refereegranskat)
  • 2.
    Aronsson, Inga-Lill
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Det sårbara informationssamhället1989Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Rapporten diskuterar det moderna, informationssamhällets sårbarhet vad gäller varnings- och larmsystem. Rapporten beskriver vad som kan hända under kraftiga åskväder när olika system slås ut. Olika fallstudier presenteras från sjukhus och larmcentraler.

  • 3.
    Aronsson, Inga-Lill
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Human Response to the Lightning Hazard in a Cultural Context1986Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This paper explores the human responses to lightning hazards from a cultural anthropological perspective. By definition, a natural hazard involves human action, initiative, and choices. There is always an interaction between man and nature, because humans respond and adapt themselves to the natural phenomena. These adjustments and responses differ from one society to another. The author was, at the time of writing, affiliated to both the Institute of High Voltage Research, and, the Department of Cultural Anthropology, Uppsala University.

  • 4.
    Bendjamin, J
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R
    Scuka, V
    Time varying electromagnetic fields generated by electrostatic discharges1997Ingår i: The First IEEE International Symposium on Polymeric Electronics Packaging, Norrköping, Oct 27-29, 1997, s. 197-202Konferensbidrag (Refereegranskat)
  • 5.
    Bendjamin, John
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Characteristics of electrostatic discharges (ESD) based on current,optical and magnetic radiation fields2000Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In this thesis parameters characterising electrostatic discharges such as the current, the magnetic fieldand the optical radiation are investigated. Optical radiation and magnetic fields generated by ESD aremeasured together with their current signatures in the time domain. Observations show that during theinitial growth, the temporal variation of the optical pulse is similar to that of the current. The peakcurrent is linearly correlated to the peak optical radiation, with a correlation coefficient of about 0.9.The results show that both the optical radiation and the magnetic fields can be used to remote sense thecurrents in electrostatic discharges, which is difficult to measure directly.

    It is shown that magnetic fields very close to an ESD can be predicted by modelling theradiating discharge current path as a sequence of electric dipoles. Time domain measurements of thecurrent and the magnetic fields generated by human-metal electrostatic discharges produced by an ESDgenerator are used for verification. An ESD current with a peak of 28 A and a risetime of 10 ns cancreate magnetic flux density derivative of about 105 T/s at a distance of 10 mm from the discharge.

    Current generated by ESD events between metal electrodes and a finitely conducting mediumwere measured simultaneously with their magnetic fields and optical radiation in the time domain.Finitely conducting water was used as the medium. The conductivity of water was changed by addingsalt (NaCl) and an ESD was applied through a point plane electrode configuration with a fixed gapdistance. For a given voltage, the peak current and the peak magnetic field derivative increases withincreasing conductivity. The duration of the ESD current also varies with the conductivity of water. Itincreases with decreasing conductivity initially but reaches a maximum and then starts to decreaseagain. It is shown that an RLC model canpredict the general features of the experimental results.

    Magnetic fields and optical radiation generated by ESD from metal objects held by peopletogether with their current signatures are also measured in the time domain. The peak measured currentwaveforms are between 25-50 A and the risetime is about 10 ns for a 10 kV discharge, which wassimilar to the current measured from the human body model ESD generator (IEC 801-2). The resultscan be used to estimate the RLC circuit components of the human body model ESD generator.

  • 6.
    Berg, MJ
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R
    Scuka, V
    A digital image processing method for estimating the level of hydrophobicity of high voltage polymeric insulating materials1999Ingår i: IEEE Conference on Electrical Insulation and Dielectric Phenomena, Austin, Texas, USA, October 17-21, 1999Konferensbidrag (Refereegranskat)
  • 7. Bjerselius, R
    et al.
    Aune, M
    Darnerud, P-O
    Atuma, S
    Tysklind, M
    Bergek, S
    Lundstedt-Enkel, K
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för fysiologi och utvecklingsbiologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för fysiologi och utvecklingsbiologi, Ekotoxikologi.
    Glynn, A
    Tekniska sektionen, Institutionen för högspänningsforskning. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för fysiologi och utvecklingsbiologi, Ekotoxikologi.
    Resultat av analys av dioxin och dioxinlika PCB i fisk från Östersjön, Vänern och Vättern2002Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 8.
    Blennow, J
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Sjöberg, M
    Leijon, M
    Gubanski, S
    Electric Field Reduction Due to Charge Accumulation in Dielectric-Covered Electrode System2000Ingår i: IEEE Transactions on Dielectrics and Insulation, Vol. 7, nr 3, s. 340-345Artikel i tidskrift (Refereegranskat)
  • 9.
    Cooray, V
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Charge and Voltage Characteristics of Corona Discharges in a Coaxial Geometry2000Ingår i: IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 7, nr 6Artikel i tidskrift (Refereegranskat)
  • 10.
    Cooray, V
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    The modelling of positive return strokes in lightning flashes2000Ingår i: Journal of Atmospheric and Solar-Terrestrial Physics, Vol. 62, s. 169-187Artikel i tidskrift (Refereegranskat)
  • 11.
    Cooray, V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap. Institutionen för högspänningsforskning.
    Fernando, M
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper.
    Sörensen, M
    Götschl, T
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper.
    Pedersen, A
    Propagation of lightning generated transient electromagnetic fields over finitely conducting ground2000Ingår i: Journal of Atmospheric and Solar-Terrestrial Physics, Vol. 62, s. 583-600Artikel i tidskrift (Refereegranskat)
  • 12.
    Cooray, V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Galván, A
    A Negative First Return Stroke Model For Engineering Applications2000Ingår i: 25th International Conference on Lightning Protection, Rhodos, Greece, 2000Konferensbidrag (Refereegranskat)
  • 13.
    Cooray, V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Galván, A
    The Stepped Leader As A Source of Interference In Electrical Installations2000Ingår i: 25th International Conference on Lightning Protection, Rhodos, Greece, 2000Konferensbidrag (Refereegranskat)
  • 14.
    Cooray, V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Jayaratne, R
    What directs a lightning flash towards ground?2000Ingår i: Sri Lankan Journal of Physics, Vol. 1, s. 1-10Artikel i tidskrift (Refereegranskat)
  • 15.
    Dahlgren, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Frank, H
    Leijon, M
    Owman, F
    Walfridsson, L
    Windformer - Windpower goes large-scale2000Ingår i: ABB Review, nr 3Artikel i tidskrift (Övrigt vetenskapligt)
  • 16.
    Galvan, A
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Cooray, V
    Thottappillil, R
    Scuka, V
    Effects of lightning electromagnetic field pulses (LEMP) in low voltage power installations1998Ingår i: 24th International Conference on Lightning Protection (ICLP), Birmingham, UK, Sept 14-18, 1998, s. 729-734Konferensbidrag (Refereegranskat)
  • 17.
    Galván, A
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Cooray, V
    Analytical Simulation of Lightning Induced Voltages in Low Voltage Power Installations2000Ingår i: 25th International Conference on Lightning Protection, Rhodos, Greece, 2000Konferensbidrag (Refereegranskat)
  • 18.
    Galván, A
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Fernando, M
    Operative characteristics of a parallel-plate antenna to measure vertical electric fields from lightning flashes2000Rapport (Övrigt vetenskapligt)
  • 19.
    Galván Diego, Arturo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Simulation of lightning electromagnetic fields and their interaction with low voltage power installations: By Arturo Galván Diego2000Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    An increasing number of damages of electric nature are being observed on modem electronic sensitiveequipment connected to low voltage power installation (LVPI) networks when they are exposed tolightning electromagnetic fields (LEMPs), or indeed, any other electromagnetic pulse (EMP). The wayin which these fields affect the electronic equipment depends on the properties of the interferencesource, the electromagnetic interaction and the hardness of the device. The aim of this study was tomodel some of the process of the lightning flash that generate the adverse electromagneticenvironment and to investigate the transient response of simple and complex LVPI networks whenexposed to natural lightning Sashes.

    Two models, based on experimental observations in long sparks, were developed to describe thestepped leader and the return stroke processes of cloud-to-ground flashes. The models, which are ableto reproduce the main features of measured LEMPs, can easily be used or adapted for engineeringpurposes in order to evaluate, by analytical simulations, overvoltages upon aerial and undergroundcables.

    Two analytical techniques, one for simple and other for complex installations, were developed andvalidated by experimental data gathered when several LVPI networks were exposed to LEMPs. Thepredictions of the lightning induced voltages upon the networks are done in time domain, avoidingcomplex Fourier transformations otherwise required in other proposed models.

    By using the two techniques, the transient response of different LVPI networks to lightningelectromagnetic fields generated by natural lightning flashes was investigated. It was found that theamplitude and wave shape of the lightning induced voltage upon the networks depends on thefollowing factors: source of interference, value and position of the loads connected to the LVPI,measuring point, angle of incidence, height of the installation, soil conductivity, number of outlets andthe effect produced by the natural shielding of the building housing the aerial conductors.

  • 20.
    Gao, L
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Akyuz, M
    Larsson, A
    Cooray, V
    Scuka, V
    Measurement of the positive streamer charge2000Ingår i: Journal of Physics D: Applied Physics, Vol. 33, s. 1861-1865Artikel i tidskrift (Refereegranskat)
  • 21.
    Gao, L
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Cooray, V
    Thottappillil, R
    Scuka, V
    Study of cathode-directed positive streamers in air by streamer current and luminosity measurements1997Ingår i: IEEE Conference on Electrical Insulation and Dielectric Phenomena, Minneapolis, USA, Oct 19-22, 1997, s. 587-590Konferensbidrag (Refereegranskat)
  • 22.
    Gao, Lan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Characteristics of streamer discharges in air and along insulating surfaces2000Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Power quality is dependent on the dielectric properties of the insulators used throughout the power generation and power transmission utilities. Knowledge of the pre-discharge stage associated with the electrical breakdown across outdoor insulators is essential if one is to improve the performance of these insulators under various electrical and environmentalconditions. The streamer discharge is an important sub-process in the development of partial and disruptive discharges. Parameters concerning the propagation of streamer discharges in air and along insulator surfaces are thus of importance for understanding the way in which the streamer characteristics can be influenced. The studies reported in this thesis were made on streamer discharges in air and over insulating surfaces at atmospheric pressure.

    Experiments on positive streamer discharges in air are presented. Currents associated with streamer discharges have been measured in a three-electrode gap system that provides a quasi-uniform electric field. Parameters for the streamer discharges such as the electric field required for the stable streamer propagation, speed of the streamer propagation and the chargeinvolved in the streamer discharge have been investigated. A simplified streamer model, assuming the streamer as a finitely conducting channel has been studied through computer simulation. The agreement between experiments and simulations has shown that this model can predict some properties of the streamer discharges.

    Experiments on streamer propagation over insulating surfaces and the comparison of breakdown channels in air and along insulator surfaces have been reported. Differences between streamer discharges in air alone and streamer discharges over insulating surfaces have been discussed. It is suggested that the charge deposited on the insulator surface plays asignificant role in determining whether the spark channel follows the insulator surface or takes a path in air.

    In an attempt to develop diagnostic tools for investigation of the charge density and the amount of energy required to initiate a discharge in an ambient electric field, the effect of absorbed laser pulse energy has been studied for laser triggered electrical discharges.

  • 23.
    Gomes, C
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Cooray, V
    Concepts of Lightning Return Stroke Models2000Ingår i: IEEE Transactions on Electromagnetic compatibility, Vol. 42, nr 1Artikel i tidskrift (Refereegranskat)
  • 24.
    Gomes, C
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R, Scuka, V
    Bipolar electric field pulses in lightning flashes over Sweden1997Ingår i: Paper 31F4, 12th International Zurich Symposium & Technical Exhibition on Electromagnetic Compatibility, Feb 17-21, 1997Konferensbidrag (Refereegranskat)
  • 25.
    Holmberg, Pär
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Modelling the transient response of windings, laminated steel coresand electromagnetic power devices by means of lumped circuits: With special reference to windings with a coaxial insulation system2000Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. This is the case for the explosive magnetic flux compression generator (EMG) and a ferromagnetic actuator.

    Models are presented that are mainly intended for transients in the millisecond range and faster. Hence, eddy currents and the related skin and proximity effect become significant in windings, magnetic cores and in the armatures of the devices. These effects are important for, e.g., the damping of the transients. Further, the displacement current in the insulation of the winding is significant. It changes the response of the windings dramatically, as it manifests the finite velocity of propagation of the electromagnetic fields. Under such circumstances, reflections and excited resonances can make the transient voltage and current distribution highly irregular.

    Induced voltages are modelled with self and mutual inductances or reluctances combined with winding templates. The displacement currents are modelled with capacitances or coefficients of potential. Cauer circuits and their dual form are used to model eddy currents in laminated cores and in conductors. The Cauer circuit enables one to consider hysteresis and the non-linear response of a magnetic core. It is also used to model the eddy currents in the moving armature of an EMG.

    A set-up is presented that can be used to study the transient voltage and the current distribution along a coil.

    The transient response of coaxially insulated windings is analysed and modelled in detail. A lumped circuit model is developed for a coil, DryformerTM - the new high-voltage transformer - and PowerformerTM, the new high-voltage generator. An alternative model, a combined lumped circuit and FEM model, is presented for a coaxially insulated winding in two slot cores.

  • 26.
    Larsson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Inhibited electrical discharges in air1997Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Modem society requires a stable electricity supply, the reliability of which is partlydetermined by the dielectric strength of the outdoor high-voltage insulation systems.This thesis concentrates upon one particular discharge phenomenon that occurs whensuch a system is subjected to rain, namely the inhibited discharge. This is a dischargewhere the energy input into the discharge channel is limited by the presence of a largeseries resistor in the discharge circuit.

    Two experimental arrangements have been used: A quasi-uniform 10 mm electrodegap (simulating discharges between water drops) and a rod-to-plane 1 m electrode gap(simulating the flashover of a high-voltage post insulator).The presence of the series resistance caused no increase in the disruptive dischargevoltage for the 10 mm gap, but for the 1 m gap it induced an increase that was morepronounced for negative than positive polarity.

    The transition from a cold discharge to a hot plasma was significantly prolongedwhen a large series resistance was introduced in the discharge circuit. This is interestingfor engineering purposes since it increases the time window in which action can betaken before the end of the disruptive discharge.

    A five order-of-magnitude difference in the peak streamer-to-spark transition current(1 mA - 100 A) was found in the literature for 10 mm gaps. This difference has notbeen thoroughly investigated previously. Here an explanation is suggested for thisphenomenon.

    The experimental results revealed that the streamer propagation was not inhibited bythe presence of a large series resistance in the discharge circuit, but the final jump was.The effect upon streamer propagation was confirmed by calculations using a well-established streamer model. A final-jump model was derived as part of the work presented here and good agreement was obtained between the experiments and the calculations. This model should be useful in the design of high-voltage insulators.

  • 27.
    Leijon, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Andersson, T
    High and Dry2000Ingår i: IEE Review, nr JulyArtikel i tidskrift (Refereegranskat)
  • 28.
    Leijon, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Jaksts, A
    Sasse, C
    Frank, H
    Fogelberg, T
    Andersson, T
    Forsmark, S
    Nilsson, L
    Sjögren, A
    A major Breakthrough in Transformer Technology2000Rapport (Övrigt vetenskapligt)
  • 29.
    Manyahi, James Mighanda
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Response of Transformers to Lightning Transients and Their Transfer Between the Transformer Circuits2000Licentiatavhandling, monografi (Övrigt vetenskapligt)
  • 30.
    Manyahi, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R
    A method for Estimating the LEMP Environment of Facilities Using the Lightning Location System2000Ingår i: 25th International Conference on Lightning Protection, Rhodos, Greece, 2000Konferensbidrag (Refereegranskat)
  • 31.
    Manyahi, M.J., Thottappillil, R., Scuka, V.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Transient Response of Equipment Transformers1999Ingår i: proceedings, 1999 International Conference on Electrical Engineering and Technology, Dar Es Salaam, Tanzania , 1999Konferensbidrag (Övrigt vetenskapligt)
  • 32.
    Popov, M., He, S., Thottappillil, R.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Reconstruction of lightning currents and return stroke model parameters using remote electromagnetic fields1999Ingår i: Abstract, XXVIth General Assembly of the International Union of Radio Science (URSI), Toronto, Canada , 1999Konferensbidrag (Övrigt vetenskapligt)
  • 33.
    Popov, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    He, S
    Thottappillil, R
    Reconstruction of lightning currents and return stroke model parameters using remote electromagnetic fields2000Ingår i: Journal of Geophysical Research, Vol. 105, s. 24469-24481Artikel i tidskrift (Refereegranskat)
  • 34.
    Rakov, VA
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R
    Uman, MA
    Barker, PP
    Mechanism of the lightning M Component1995Ingår i: J. Geophys. Res., Vol. 100, s. 25701-25710Artikel i tidskrift (Refereegranskat)
  • 35.
    Rakov, VA
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Uman, MA
    Thottappillil, R
    Review of recent lightning research at the University of Florida1995Ingår i: Electrotechnik und Informationstechnik, Vol. 112, nr 6, s. 262-265Artikel i tidskrift (Refereegranskat)
  • 36.
    Rakov, VA
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Uman, MA
    Thottappillil, R
    Eybert-Berard, A
    Berlandis, JP
    Lalande, P
    Laroche, P
    Fisher, RJ
    Schnetzer, GH
    New insights into lightning processes gained from the triggered-lightning experiments in Florida and Alabama1996Ingår i: 10th International Conference on Atmospheric Electricity, Osaka, Japan, June 10-14, 1996, s. 672-675Konferensbidrag (Refereegranskat)
  • 37.
    Rakow, VA
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Uman, MA
    Thottappillil, R
    Eybert-Berard, A
    Berlandis, JP, Rachidi, F
    Rubinstein, M
    Nucci, CA
    Guerrieri, S
    Observed electromagnetic environment close to the lightning channel1996Ingår i: 23rd International Conference on Lightning Protection (ICLP), Florence, Italy, Sept 23-27, 1996, s. 30-35Konferensbidrag (Refereegranskat)
  • 38.
    Rubinstein, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Rachidi, M
    Uman, MA, Thottappillil, R
    Characterization of vertical electric fields 500 m and 30 m from triggered lightning1995Ingår i: J. Geophys. Res., Vol. 100, s. 8863-8872Artikel i tidskrift (Refereegranskat)
  • 39.
    Silfverskiöld, S
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Bäckström, M
    Lorén, J
    Microwave Field-to-Wire Coupling Measurements in Anechoic and Reverberation Chambers2000Rapport (Övrigt vetenskapligt)
  • 40.
    Silfverskiöld, S
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Thottappillil, R
    Ming, Y
    Cooray, V
    Scuka, V
    Induced voltages in a low voltage power installation network due to lightning electromagnetic fields1996Ingår i: 23rd International Conference on Lightning Protection (ICLP), Florence, Italy, Sept 23-27, 1996, s. 334-339Konferensbidrag (Refereegranskat)
  • 41.
    Sjöberg, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Blennow, J
    Gubanski, S
    Leijon, M
    On Discharge Phenomena in a Covered Electrode System in Air2000Ingår i: IEEE International Symposium on Electrical Insulation, Anaheim, USA, 2000, s. 345-348Konferensbidrag (Refereegranskat)
  • 42.
    Sjöberg, M
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Blennow, J
    Leijon, M
    Gubanski, S
    The Electric Field Reduction in a Covered Electrode Gap due to Ionization and Charge Accumulation2000Ingår i: 6th International DC High Voltage Symposium, Hamburg, Germany, 2000Konferensbidrag (Refereegranskat)
  • 43.
    Tang, Hong
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Transient control in low-voltage power installation networks and electronic systems1997Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Transient protection in a low-voltage power installation network and an electronic system isof vital importance since most of the activities of our society are very dependent on thereliability of low-voltage power installation networks and electronic systems. This thesisconcentrates upon several investigations which all deal with the evaluation and improvementof the protection measures of low-voltage power installation networks and electronic systemsagainst electrical transients.

    Different components of transient protection circuits, such as varistors, gas dischargeprotectors and shielded cables, and their co-ordination in complex protection circuits havebeen experimentally investigated. The transient response of an individual protectioncomponent together with a complex protection system is discussed. Using a direct "high-level" current injection, a shielded system including non-linear circuit components wasevaluated experimentally. Based on the theoretical analysis, self-consistent time domainmodels of the varistor, the gas discharge protector, the power installation cable and theshielded cable were developed and implemented under the Alternative Transients Program -Electromagnetic Transients Program (ATP-EMTP). A good agreement was obtained incomparing the measured and the calculated results even for a complex protection circuit. Themodels developed in this thesis are shown to be a very efficient tool in the evaluation ofprotective measures in low-voltage power installation networks and in electronic systems.Different protection schemes for a protection circuit are also discussed in this thesis.

    A mid-plane triggered spark gap trigatron was also theoretically and experimentallyinvestigated. On the basis of these investigations, an optimised trigatron spark gap wasdeveloped and used in the construction of a new low impedance impulse current generatorwhich was used in the experiments described in this thesis.

  • 44.
    Thottappillil, R
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    A review of lightning with emphasis on the properties important for the protection of ground based assets2000Ingår i: A document prepared for Försvarets Materielverk under contractÖvrigt (Övrigt vetenskapligt)
  • 45.
    Thottappillil, R
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Electromagnetic environment models for Cloud-To-Ground Lightning2000Ingår i: 25th International Conference on Lightning Protection, Rhodos, Greece, 2000Konferensbidrag (Refereegranskat)
  • 46.
    Thottappillil, R
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Lightning effects on installations1996Konferensbidrag (Övrigt vetenskapligt)
  • 47.
    Thottappillil, R
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Goldberg, J
    Rakov, VA
    Uman, MA
    Fisher, RJ
    Schnetzer, GH
    Properties of lightning M components from currents measured at triggered lightning channel base1995Ingår i: J. Geophys. Res., Vol. 100, s. 25711-25720Artikel i tidskrift (Refereegranskat)
  • 48.
    Thottappillil, R
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Rakov, VA
    Uman, MA
    Time domain expressions for remote electric and magnetic fields in terms of the charge distribution along the lightning channel1996Ingår i: 23rd International Conference on Lightning Protection (ICLP), Florence, Italy, Sept 23-27, 1996, s. 291-296Konferensbidrag (Refereegranskat)
  • 49.
    Thottappillil, R
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Scuka, V
    Eriksson, J
    Eriksson, A
    Öhman, P
    Estimation of fields radiated by a PCB from close magnetic field measurements1997Ingår i: 10th International Conference on Electromagnetic Compatibility, University of Warwick, UK, IEE Conf. Publication, Sept 1-3, 1997, nr 445, s. 89-93Konferensbidrag (Refereegranskat)
  • 50.
    Thottappillil, R
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för högspänningsforskning.
    Uman, MA
    Rakov, VA
    Comments on the significance of retardation effects in calculating the radiated electromagnetic fields from an extending discharge1997Ingår i: Paper 13C3, 12th International Zurich Symposium & Technical Exhibition on Electromagnetic Compatibility, Feb 17-21, 1997Konferensbidrag (Refereegranskat)
12 1 - 50 av 58
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