EMCABS: 01-02-2011
LONG-TERM POWER QUALITY MONITORING IN DISTRIBUTION NETWORKS
+ Pavel Santarius, + Petr Krejci, + Radovan Hajovsky and ++ Radim Cumpelik
+ VSB-Technical University of Ostrava, Czech Republic
++ CEZ– a.s., Czech Republic
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 13–16.
Abstract: In the power company CEZ in the North Moravia Region (the Czech Republic) the monitoring of a number of selected parameters of the quality of electrical energy (harmonics, flicker and unbalance) is being carried out in cooperation with research laboratories of the Faculty of Electrical Engineering and Computer Science, VSB- Technical University of Ostrava. The monitoring is being carried out in a complex manner in 59 feeding points 400 V, always within one week intervals, and at the same time on all voltage levels (HV, MV and LV). In the paper, the results of the complex monitoring during 12 years are summarized together with the comparison of the changes of parameters after three years. In addition, the results of annual continual monitoring for one selected locality on an MV level are presented in the paper.
Index terms: Power quality, harmonics, flicker, unbalance.
EMCABS: 02-02-2011
INVESTIGATION OF EVALUATING METHOD OF INFLUENCES BY DISTURBANCES ON DIGITAL TV USING ACTUAL BROADCASTING SIGNAL
Nobuo Kuwabara and Shohei Yanagi
Department of Electrical Engineering and Electronics, Kyushu Institute of Technology, Japan
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 29–32.
Abstract: Influence by the disturbances from the electrical equipment was investigated by using the actual broadcasting signal. The disturbances from the equipment were measured by an oscilloscope and were generated by the arbitrarily waveform generator The TV signal and the disturbances level were evaluated by a quasi peak value, an amplitude probability distribution and an average power. The influences on received images were evaluated by mean opinion score (MOS). The relation between MOS and these signal levels were investigated concerning the actual digital TV signal and the analog TV signal. The results suggested that the evaluation by the average power was appropriate because the method could reduce the influence on the kind of disturbance.
Index terms: Analog TV, digital TV, disturbances, APD, quasi peak, average power, mean opinion score.
EMCABS: 03-02-2011
FORCASTING AND FINDING ELECTROMAGNETIC SHIP’S SIGNATURES
+ Krzysztof Dymarkowski, + Rafal Namiotko, ++ Grzegorz Pettke and ++ Edward Szmit
+ OBR Centrum Techniki Morskiej S.A., Poland, ++ Polski Rejestr Statkow S.A., Poland
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 33–36.
Abstract: The paper presents a matrix model of platform/ship structure and the topological approach for the assessment of electromagnetic field signature. The model is developed on the basis of an assumption taking into account the sources of electromagnetic emissions, the ship’s structure discontinuity, including manholes, cable passes, casings, etc. An analysis of the electromagnetic emission paths out of the ship’s hull is also included.
Index terms: Ship’s electromagnetic field signature, electromagnetic emission, naval ship, electromagnetic topology.
EMCABS: 04-02-2011
SHIELDING EFFECTIVENESS OF GRADIENT LIQUID-CONTAINING COMPOSITE MATERIALS
Natallia Nasonova, Tatiana Pulko, Galina Pukhir, Vjacheslav Kizimenko and Leonid Lynkov
Belarusian State University of Informatics and Radioelectronics, Belarus
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 57–60.
Abstract: In order to reduce the reflectivity of metal objects, radio absorbing materials are commonly used. Using the CST Microwave Studio 2010 we model the frequency characteristics of electromagnetic radiation reflection through an RCS calculation in the SHF range. We show that by applying the dielectric layers on a metal surface, its RCS decreases as a result of dissipation of the electromagnetic energy. The highest efficiency of RCS decreasing on the metal plate is ensured by a three-layered structure comprising a low-loss dielectric layer as the first matching layer, a high-loss dielectric layer as the second matching layer and a metal plate. Results of real RCS decrease by a developed double-layered composite liquid-containing structure are given.
Index terms: Liquid dielectrics, radar cross-section, electromagnetic radiation, modeling.
EMCABS: 05-02-2011
MONITORING SYSTEM CONSIDERING TIME VARYING ELECTROMAGNETIC FIELDS IN MAGNETIC FUSION TEST FACILITIES
+ Tatsuhiko Uda, + Masahiro Tanaka, ++ Shizuhiko Deji, +++ Yoshitsugu Kamimura, ++++ Jianqing Wang and ++++ Osamu Fujiwara
+ National Institute for Fusion Science, ++ Kobe Co-Medical College, +++ Utsunomiya University, ++++ Nagoya Institute of Technology, Japan
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 67–70.
Abstract: To consider occupational safety management from static magnetic field to high frequencies of electromagnetic fields, the electric and magnetic fields had been measured around a magnetic fusion plasma test facility of a Large Helical Device (LHD). The LHD uses a superconductive coils system and high-power radio frequency wave devices for auxiliary plasma heating. Although usual leakage of the electric and magnetic fields were less than the regulation level, it shows time-dependently and statistical variation according to plasma shots and experimental condition. To establish the continuous monitoring system desired in such a facility, the authors used some instruments, including the convenient personal monitors, to confirm their sensitivity had been examined and clarified their applicability.
Index terms: Magnetic fusion plasma, electromagnetic fields measurement, safety management.
EMCABS: 06-02-2011
INVESTIGATION OF COMPACT FLUORESCENT LAMPS ELECTROMAGNETIC RADIATION
Konstantinas Otas, Alfonsas Vaskys and Paulius Vaskys
Kaunas University of Technology, Lithuania
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 95–98.
Abstract: EU decided to phase out the sale of incandescent light bulbs in the coming years in favor of much more efficient compact fluorescent lamps (CFLs). The CFLs for replacing 100 W incandescent lamps (ILs) and most widely found on the Lithuania market were selected for experimental investigation in this work. Lamp current, power, power factor, light output and UV radiation of 27 CFLs of different brands were investigated. UV radiation evaluation of tested lamps was carried out. |
|
Index terms: Compact fluorescent lamp, CFL, lamp current, lamp power, lamp luminous flux, UV radiation.
EMCABS: 07-02-2011
ESTIMATION OF GAP BREAKDOWN FIELD FOR AIR DISCHARGES OF ESD-GUN WITH LOW CHARGE VOLTAGES
+ Ikuko Mori and ++ Osamu Fujiwara
+ Suzuka National College of Technology, ++ Nagoya Institute of Technology, Japan
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 111–114.
Abstract: To grasp the characteristics of air discharge of ESD-guns with low charge voltages, the gap breakdown field is estimated using a discharge circuit approach with the maximum current rising slope and peak current. At the same time, because the rise time below several hundred volts reaches the measurement limit of the oscilloscope, real discharge current waveforms are reconstructed using complex frequency response of the second order low pass filter of the oscilloscope and then gap breakdown field in this case is also estimated. As a result, the gap breakdown field can be estimated approximately 2.6 × 107 V/m below charge voltage of 600 V and those obtained from reconstructed waveforms gives higher values and below 400 V they are estimated to be 3 × 107 V/m.
Index terms: Electrostatic discharge (ESD), ESD-gun, air discharge, low charge voltage, circuit approach, gap breakdown field.
EMCABS: 08-02-2011
CURRENT-POTENTIAL MEASURING METHOD FOR ESTIMATION OF THREAT RELATED TO LIGHTNING STRIKE TO A RADIO BASE STATION
Renata Markowska, Jaroslaw Wiater and Andrzej Sowa
Bialystok University of Technology, Poland
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 141–146.
Abstract: The paper presents a methodology and provides an example showing results of on-site measurements of surge current flows and potentials in a radio base station. The basic idea of the method is to simulate a lightning strike to the base station tower using a surge generator and to measure surge current flows and potentials with respect to remote ground at various elements of the station. The aim of the experiment was to provide complex information on the performance of a radio base station affected by surge currents. This information may be used in further theoretical analysis of lightning threats for testing and verification of numerical models and/or for analysis of various lightning protection measures.
Index terms: Direct lightning strike, communication tower, on-site simulation of lightning strike, measurements, surge current flow, ground potential rise.
EMCABS: 09-02-2011
SEPARATION DISTANCES IN LIGHTNING PROTECTION OF ANTENNAS
Andrzej W. Sowa
Bialystok University of Technology, Poland
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 151–154.
Abstract: An antenna mast on the roof of a structure should be protected against direct lighting strike. To achieve such protection, it should lay within the protective spaces and have a minimum separation distance between mast and element of air-termination system required. In this paper, the study of separation distances for different wave shapes of lighting surge voltage is presented.
Index terms: Lighting protection, antennas, separation distances.
EMCABS: 10-02-2011
INVESTIGATION OF THE VOLTAGE INFLUENCE ON PARTIAL DISCHARGE CHARACTERISTIC PARAMETERS IN SOLID INSULATION
+ Povilas Valatka and ++ Gediminas Dauksys
+ Department of Electric Power Systems, Kaunas University of Technology
++ Department of Electric Power Systems, Kaunas University of Technology, Kaunas Technical College, Lithuania
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 155–158.
Abstract: The solid insulations of electrical equipment are perpetually affected by various duration of over voltages and over currents. Depending on its duration, the over voltage event can be transient- a voltage spike, or permanent, leading to a power surge. Electric stress of insulation depends on its thickness and amplitude of applied voltage. The damaged solid insulation may also influence characteristic parameters of partial discharges. The characteristic parameters of solid insulation quality should be permanently evaluated. The paper discusses the voltage influence on partial discharge characteristic parameters in the solid insulation. Partial discharge values of different sizes and shapes of solid insulation defects under different voltage influences are evaluated.
Index terms: Partial discharge, partial discharge characteristics, overvoltage, dielectric, solid insulation.
EMCABS: 11-02-2011
INFLUENCE OF SLOTTED ENCLOSURE RADIATION PATTERN ON MESUREMENTS OF SHIELDING EFFECTIVENESS IN GTEM CELL
Andrzej Rusiecki
Bialystok Technical University, Faculty of Electrical Engineering, Poland
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 169–172.
Abstract: Influence of the radiation pattern of slotted enclosure on results of shielding effectiveness (SE) measurements in a GTEM cell is presented. The measurement results are compared to the calculated Far-Field (FFLD) emission of the enclosure. The effect of the spatial radiation pattern on the SE calculations has been taken into account using a Poynting vector integration. Differences in measured SE for different equipment setups in GTEM cell are presented.
Index terms: Shielding effectiveness, slotted enclosure, GTEM, far-field, Poynting vector integration.
EMCABS: 12-02-2011
EXPERIMENTAL RESEARCH OF PULSE PROCESSES IN THE OBJECT GROUNDING SYSTEM
+, ++ Nerijus Bagdanavicius, + Anatolijus Drabatiukas, + Sarunas Kilius and ++ Alfonsas Morkvenas
+ Kaunas Technical College, Lithuania
++ Kaunas University of Technology, Lithuania
Proceedings of XX International Conference on Electromagnetic Disturbances, Kaunas University of Technology, Lithuania, September 22–24, 2010, pp. 173–178.
Abstract: The suitable grounding of sensitive electronic equipment cases in the building objects is one of the measures to reduce the effect of the disturbances which arise due to the lightning impact or various commutations in the power supply network. The data registration and analysis is essential when characterizing such disturbances. Registration demonstrates the real statistical parameters in the particular objects. In this work, the influence of the object grounding system on the disturbances induced by the lightning discharge is evaluated.
Index terms: Surge, surge registration, test pulse, electromagnetic pulse, grounding system. EMC
|
EMCABS
