• Title/Summary/Keyword: DC Corona Current Pulse

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Trichel Pulse in Negative DC Corona discharge and Its Electromagnetic Radiations

  • Zhang, Yu;Liu, Li-Juan;Miao, Jin-Song;Peng, Zu-Lin;Ouyang, Ji-Ting
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1174-1180
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    • 2015
  • We investigate in this paper the radiated electromagnetic waves together with the discharge characteristics of Trichel pulse of negative DC corona discharge in air in pin-to-plate and wire-to-plate configurations. The feature of the current pulse and the frequency spectrum of the electromagnetic radiations were measured under various pressures and gas gaps. The results show that the repetition frequency and the amplitude of Trichel pulse current depend on the discharge conditions, but the rising time of the pulse relates only to the radius of needle or wire and keeps constant even if the other conditions (including the discharge current, the gas gap and the gas pressure) change. There exists the characterized spectrum of electromagnetic waves from negative corona discharge in Trichel pulse regime. These characterized radiations do not change their frequency at a given cathode geometry even if the averaged current, the gas gap or the air pressure changes, but the amplitude of radiations changes accordingly. The characterized electromagnetic radiations from Trichel pulse corona relate to the formation or the rising edge of current pulse. It confirms that the characterized radiations from Trichel pulse supply information of discharge system and provide a potential method for detecting charged targets.

Characteristics of DC Corona Discharges Caused at the tip of a Needle-shaped Electrode Placed in the Homogeneous Electric Fields (균등전계 중에 놓인 침상 전극의 끝단에서 발생한 직류 코로나방전 특성)

  • Kim, Tae-Ki;Kim, Seung-Min;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.11
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    • pp.74-81
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    • 2015
  • In the measurement of atmospheric static electric field, it is important to know characteristics of corona discharges caused at the tip of test electrode. This paper presents the fundamental data of DC corona discharges that occurred at the tip of a needle-shaped electrode placed in the homogeneous background electric field which simulates the atmospheric static field under thundercloud. The major characteristics of interest for this purpose are the polarity effect of corona discharges and the magnitudes and time intervals of corona current pulses. The experimental set-up consists of the plate-to-plate configuration with a needle-shaped protrusion, DC power supply, and voltage and current measuring devices. As a result of experiments, the polarity dependence of corona pulses is significantly pronounced. The time intervals between successive corona pulses in the negative polarity is much longer than those in the positive polarity. The time intervals for both polarities is drastically decreased as the applied electric field is increased. Also the magnitudes of the positive corona pulses are slightly changed with an increase in applied electric field, but those of the negative corona pulses are linearly increased with increasing the applied electric fields.

Experimental Study of DC Coronas in Point-to-Plane Short Gap (지간적 직류Corona의 실질적 검토)

  • 오철한;이성만
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.5
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    • pp.157-163
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    • 1983
  • Positive and negative coronas in point-to-plane short gap have been investigated with the variations of point radius and gap length. Mainly the onset potentials and current pulses under various conditions were measured with a 70 MHz C.R.O. and a precise-controllable D.C. power supply. In the case of negative corona, the Trichel pulse corona, glow corona and spark regions were distinguished apparently and the critical gap lengths between them were also found clearly. In the case of positive corona, there are streamer corona, spark regions and the critical gap length between them, too. The current pulse forms of Trichel pulse corona of negative and streamer pulse corona of positive are similar in rising time, peak-to-peak time and pulse width. The glow corona current shows D.C. component in form.

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A Study on the Collection Characteristics of a Wide Plate-Spacing Electrostatic Precipitator -II. Effect of Wave Form of Pulse Energization - (광폭 전기집진기의 집진특성에 판한 연구 - II. 펄스 하전 파형의 영향 -)

  • 김용진;하병길;정상현;홍원석;하대홍;유주식
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.11
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    • pp.1059-1064
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    • 2001
  • This study Investigates the effect of the wave form of pulse energization on the collection characteristics of a wide plate spacing electrostatic precipitator. For the semi-pulse energization, the peak current and voltage of the energization increases with increase of the pulse period, and the corona current increases, as pulse ratio decreases. For the micro-pulse energization, the corona current increases with increase of the pulse voltage. The collection efficiency of semi-pulse and micro-pulse energization is larger than that of DC charge.

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Design of the High Frequency Resonant Inverter for Corona Surface Processes

  • Choi, Chul-Yong;Lee, Dae-Sik
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.119-122
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    • 2005
  • A algorithm for control and performance of a pulse-density-modulated (PDM) series-resonant voltage source inverter developed for corona-dischange precesses is presented. The PDM inverter produces either a square-wave ac-voltage state or a zero-voltage state at its ac terminals to control the average output voltage under constant dc voltage and operating frequency. Moreover it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) in all the operating condition for a reduction of switching lost. Even though the corona discharge load with a strong nonlinear characteristics, new high frequency resonant inverter is shown the wide range power control from 5% to 100%.

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Corona Discharge Phenomena on the Dielectric Electrodes in High Field (고전계하에서 유전체 전극에 나타나는 코로나 현상)

  • Kim, Jung-Dal;Lee, Duck-Jin;Joo, Sung-Cheol;Jung, Jang-Gun;Chang, Gi-Hyuk;Lee, Sae-Hun
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1598-1600
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    • 1998
  • When dielectric surface electric field exceed any electric field strength on air, corona discharge is occurred from the dielectric surface. This paper presents corona discharge phenomena on the dielectric in high field were studied under application of ${\pm}DC$ voltage, constitute of the point to plane 20mm gap. The results obtained in experimental are summarized as follow :(1) Corona pulse is appeared periodically after first corona pulse is occurred and the number of corona pulse increases with the instantaneous applied voltage but peak value is not changed greatly.(2)Applied voltage to beccrite and characteristics and peak value of current are almost a straight line. That kind of tendency accorded with characteristics of beccrite resistance.(3)In case of Positive corona, Positive streamers, were progressed greatly to plane electrodes but In case of negative corona, negative streamers smaller than that of Positive corona.

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A Study on the Removal of SOx/NOx by a Pulsed Corona Discharge in the Wire-Plate Reactor (Wire-Plate 반응기에서 펄스 코로나 방전을 이용한 탈황 탈질에 관한 연구)

  • Shin, Wan-Ho;Song, Yong-Hoon;Kim, Han-Seok;Choi, Yeon-Seok;Kim, Seok-Joon
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1910-1912
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    • 1996
  • This paper presents the results of laboratory experimentals to remove $SO_2$ and $NO_x$ by a pulsed corona discharge in the wire-plate reactor. A rotating spark gap switch was used to generate the pulse by chewing the dc high voltage. Repetition frequency of the pulse was 60Hz and rising time of 50ns. The photo pictures of positive streamer corona taken by ICCD camera, pulse voltage and current were measured using a digital oscilloscope. Simultaneous effects of $C_{2}H_{4}$ injection and heterogeneous chemical reactions on nonthermal plasma process to remove $SO_2$ and $NO_x$ from flue gas were investigated in the present study

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$SO_2$ and CO Removal Characteristics in Various Applied Voltage of Nonthermal Discharge Plasma in a Crossed DC Magnetic Field (전.자계상의 전원장치변화에 따른 비열방전 플라즈마의 $SO_2$와 CO가스 제거특성)

  • Lee, Geun-Taek;Geum, Sang-Taek;Mun, Jae-Duk
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.3
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    • pp.215-220
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    • 1999
  • $SO_2$and CO gas removal characteristics of a wire-to-cylinder type nonthermal discharge plasma reactor in various applied voltage (-dc, ac, fast rising pulse and high frequency pulse) and a crossed dc magnetic field have been investigated. The experiment has been emphasized on the oxidizing characteristics of $SO_2$ and CO gas by $O_3$ and the applying of a crossed magnetic field, which would induce the cyclotronic and drift motions of electrons making the residual time longer in the removal airgap space. And it also would enhance the energy of electrons and the electrophysicochemical actions to remove the pollutant gases effectively. It is found thatthe corona onset voltage and the breakdown voltage were decreased with increasing the crossed magnetic field and decrease initial fed $SO_2$and CO concentration. As a result, a higher ozone generation and $SO_2$ and CO gas removal rate of 20[%] can be obtained with -dc, ac and fast rising pulse corona discharges in the crossed dc current-induced magnetic field. But high frequency pulse didn't show effect in applying of a crossed magnetic field.

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A High Efficiency Electrolytic Cell by Superposing Pulsed Corona Discharge in Water (수중 펄스코로나 방전을 중첩한 고효율 강전해수 발생장치)

  • 이재용;김진규;정성진;박승록;문재덕
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.2
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    • pp.79-85
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    • 2001
  • A conventional electrolyzing cell has been made by an ion exchange membrane inbetween parallel plate electrodes. A low dc voltage is applied to the electrodes for electrolyzing and the efficiency is remained in low. in this study, a novel electrolyzing cell with a pair of slit-type third electrodes installed inbetween parallel plate electrodes has been proposed and investigated experimentally. And pulse power wa supplied to between each electrodes. This slit type of third electrodes can concentrate the strong electric fields at the every its edges to accelerate the electrolyzing powers, and to generate oxygen bubble discharges for generating oxidants. And moreover the slits eliminate the space charge limiting action and the temperature of the water by leaking out through the slits from electrolyzing region to outside of the main electrode region. As a result, it was found that a strong electorzed water of pH 2.8 and pH 10.5 and oxidants dissolved water of 1 [ppm] in acidic water were obtained with a tap water fed at the electric current of 2 [A], which however were several times higher oxidant and ion concentration quantity compared with the conventional cell.

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